The infamous obd1/high stall converter problem

If anyone on this board would have a solution to this problem, you guys will. Apparently there is a problem with the obd1 cars (94-94 fbodys) having a converter higher than 2800 stall speed. I was somehow hoping that this wouldn't affect me so while my tranny was out for repair, I decided to have my stall speed raised to 3200. I guess I wasn't immune. At the track, if the car hooked, the tranny wouldn't shift from 1-2. Then it would go into some kind of a limp home mode where the overdrive wouldn't work until the car was restarted. After sending the computer out to Ed Wright for reprogramming and having that not fix the problem, decided to have the converter destalled back to the original 2800 stall speed. Have you guys dealt with this problem and what do you think it is and what do you think might be a possible solution?

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94 Z28 auto.White with white wheels.A few mods. 12.13@113 N/A with a 1.71 60'on nittos

Convert to an OBD2 PCM. This is a proven remedy. Look it up in the LT1edit archives from about 2 months ago. A lot of people tried a bunch of different things and this is what fixed it.

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96 Comp T/A #84 of 172
LS1 brakes, LT1_edit for OBDII.
TNT plate kit, a4 to M6 in progress!!!, Hooker LT's !anything not serving a go-fast purpose.

i've never had a problem with people with cars around me

we dont even use the computer to supply the line pressure anymore, we use a transgo vacuum modulator kit and dont have problems

its better off for the tranny in the end too and less troublesome than converting to OBDII

<font face="Verdana, Arial" size="2">Originally posted by 89ProchargedROC:
i've never had a problem with people with cars around me

we dont even use the computer to supply the line pressure anymore, we use a transgo vacuum modulator kit and dont have problems

its better off for the tranny in the end too and less troublesome than converting to OBDII</font>


Do you have to shift it yourself? I was running a similar setup, but had to shift it myself.

Some of the bracket racers (the only reason to even THINK about going with an automatic, IMO) didn't want to shift it, so they did the OBDII.

Mike

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1994 Sunset Orange Metallic Camaro Z28 Convertible - The Gorgeous and Sadistic Bitch Who Mistreats You and Lets You Down, Yet You Still Keep Her (http://personal.msy.bellsouth.net/~kraest/camaro.htm)


1989 Red Ford Mustang LX 5.0 Convertible - The Dependable Girl Who Treats You Right, Yet Your Mind Wanders Elsewhere (http://personal.msy.bellsouth.net/~kraest/mustang.htm)

big dave- You told Ed that the stall was a 3200? I'm surprised cause what I heard on this board was that he could fix it by adjusting the trannt tables. I'm a little worried now as I planned on 3500 stall with my heads/cam.

Yes, I did tell him it was a 3200. Apparently he redid the programming to change the gears by reading rpms instead of reading speed. It has something to do with the vss. Another interesting note was when I was going to get the obd2 computer from him, I was told that I would have to not only change the knock sensor but also a couple other things. Apparently with the 95 computers, it is far easier to do the conversion. I always thought the 94s and 95s were the same but apparently not.

KRAEST, now I didn't have to shift it by myself. It wouldn't allow me to do that. When I attempted manual shifts the same problem occurred.

<font face="Verdana, Arial" size="2">Originally posted by Kraest:

Do you have to shift it yourself? I was running a similar setup, but had to shift it myself.

Some of the bracket racers (the only reason to even THINK about going with an automatic, IMO) didn't want to shift it, so they did the OBDII.

Mike

</font>

No, you dont have to shift it yourself. The stock OBD I computer STILL shifts the transmission at whatever rpm it is programmed at

BUT

line pressure is now controlled by a vacuum modulator reading TRUE ENGINE VACUUM do give the proper line pressures.

Trans go sells the kits to convert to this style for about $110 from trans shops that are local to you and install isn't hard

<font face="Verdana, Arial" size="2">Originally posted by 89ProchargedROC:
No, you dont have to shift it yourself. The stock OBD I computer STILL shifts the transmission at whatever rpm it is programmed at

BUT

line pressure is now controlled by a vacuum modulator reading TRUE ENGINE VACUUM do give the proper line pressures.

Trans go sells the kits to convert to this style for about $110 from trans shops that are local to you and install isn't hard</font>

Do you happen to have the part #?? What if you have a hotcam, will that effect the vacuum pressure much?? In my IROC, I had to install a vacuum canister for my brakes b/c of the cam.

I have read this before, and it makes no sense to me.

Also, Pureevil (pureevil79@aol.com), a moderators on this ubb, ran at least a 4000 stall in his 95 LT1 TA last year and had no problems.

Is it me or were most of the cars having problems using LT1 Edit?

ODDII is even more complicated IMHO.

John
11.1 na LS1

<font face="Verdana, Arial" size="2">Originally posted by a_z28_vance:
Do you happen to have the part #?? What if you have a hotcam, will that effect the vacuum pressure much?? In my IROC, I had to install a vacuum canister for my brakes b/c of the cam.</font>

doesn't matter what cam you run because in actuality, the lower the vacuum reading at idle the more line pressure there will be in the tranny anyway which is a GOOD thing

no i dont have a part #

call your local transshop

When I hammer it from a slight roll it seems like the tranny is slipping. Then I let off the throttle and get back in it and its fine. Also the ABS light comes on and stays on till I turn off the car

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94 a4,3.23,K&Nfilter, 80 series Flowmaster, no cat, Jet 2 chip, Transgo shift kit, TT3000 w/2.5 str

87 GN ~106k
air bag pass side, pinion snubber, boxed trailing arms with polygraphite bushings, trans has Art Carr line pressure mods and shimmed servo, Precision 210/205 cam with new lifters, springs, and roller timing chain, and roller thrust button, blue top 36lb injectors, modified plenum, Red Armstrong ign wires, XP fuel pump, and 93 chip, K&N 12in intake breather, engine breathers (2), tiedown, alky injection

The only replacement for displacement is BOOST.

PSJ if it were just LT1 Edit WHY would Ed Write be having the problem also http://web.camaross.com/bb/wink.gif he Hex edits http://web.camaross.com/bb/biggrin.gif

OBD II is not as bad as many think and has some good advantages

Later

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11 Seconds to LOVE!
Mod's? A little of this and some of that.
Beware of what you can not see
My Ugly Old Ride (http://www.teamnwfbody.org/TeamMembers/EllisGroo.html)
REAL racers Site (http://www.teamnwfbody.org)

personally, i think you are all nutz http://web.camaross.com/bb/smile.gif

We never had a problem with trannies blowing up (high performance ones with big stalls) at my shop unless it made a lot of hp and it DIDN'T have the vacuum modulator

then YES

it would burn up in a few months or less

but with the modulator, we dont ever really have comebacks

<font face="Verdana, Arial" size="2">Originally posted by Z2FAST8:
When I hammer it from a slight roll it seems like the tranny is slipping. Then I let off the throttle and get back in it and its fine. Also the ABS light comes on and stays on till I turn off the car

</font>

That sounds exactly like my car last April. Eventually I lost OD, then D, followed by 2nd, and finally 1st. Turned out to be my TC and it had came apart and destroyed the tranny. Good thing the shop rebuilt it for free again b/c of their crappy TC.

PSJ, I have heard of a couple people NOT having problems with the 1-2 shift at WOT w/ a stall of 3200 or higher, but that has been few and far inbetween.

I must be one of those few and far betweens!!
That's GREAT! I am usually one of the few and far betweens in the negative sense!!

By the way... I run a zero-pump in my Vig..
What pump is everyone else having the trans shift problem with? Mine stalls in the 3200 range. Do any of you know the pump number in your Vig.?

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---God Speed, Good Luck and Fast Times to You!---
Kevin Hinkley (HInk) * '94 T/A GT * Best Numbers: 11.952 * 116.83 * 7.566 * 90.51 * 1.579 * Naturally Aspirated 350 ci LT1, No Nitrous, No Blower, No Turbo(s)... Just GOD's good, cold air and gobs of money! :)


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<font face="Verdana, Arial" size="2">Originally posted by a_z28_vance:
PSJ, I have heard of a couple people NOT having problems with the 1-2 shift at WOT w/ a stall of 3200 or higher, but that has been few and far inbetween.</font>

uh...not to be a smartazz but like i said, the reason why everyone blows their trannies with stalls any higher is because small diameter converters like the yanks and vigs' create TONS AND TONS OF HEAT, more than most realize.

HEAT is the #1 cause of tranny failure or lack of fluid pressure. when you have lack of fluid pressure, your clutches SLIP creating a trmendous amount of HEAT and leading to burning up the clutches and toasting the trannies

like i explained before, or maybe i didn't, the COMPUTER cannot keep up with LINE PRESSURE fast enough...what i mean is that the motor will be at where it is supposed to shift BUT the computer cannot give the tranny enough line pressure in time but STILL SHIFTS anyway...burning clutches...burning clutches, see the trend?

When you convert to a vacuum modulator, line pressure is directly related to the vacuum in the engine. The less vacuum you have, the MORE line pressure the tranny will see. So when you are at WOT and engine vacuum is basically 0in, you are getting ALL the line pressure. Where as with the computer solenoid supplying the line pressure it cannot keep up with the demand FAST ENOUGH.

Thats why when you switch to the vacuum modulator, *MOST* trannies do not break right away.

We had a problem with this when we first really started putting performances trannies in for customers with 12 second cars or faster. They were coming back with toasted trannies anywhere from a few weeks to a few months. Depended on how you drove.

When we converted them to the vacuum modulator, we almost never saw them again.

Change to a modulator setup and you'll be fine http://web.camaross.com/bb/smile.gif

well here we will just have to agree to disagree http://web.camaross.com/bb/wink.gif

the only time I use a the Modulator kit is if I have no control over the programing.

Just pulled one of our street strip 4L60Es apart for the yearly and guess what? It proves you wrong http://web.camaross.com/bb/wink.gif Use of the proper parts and proper programing left it looking great inside. I installed a new set of bearings and 3-4 clutches(usual freashen) and we are shooting for a another year!

This is in a 396 LT4 making over 400RWHP with a 9in TC.

The V-Mod is Great if you do not under stand the PCM or have no control over it. But if you do it is not needed and the PCM will give a better driving unit. I will agree the V-Mod should ALWAYS be used on Blower cars. then again I hate to see a stock PCM used on blower cars http://web.camaross.com/bb/biggrin.gif

BTW there are VERY few people who realy know what they are doing here. pick Your Trans Man wisely http://web.camaross.com/bb/wink.gif

Also I do not feel you are a smart ass. I get customers who know my job better then me every day http://web.camaross.com/bb/wink.gif A few are there for me to fix there mistakes...

Ellis"Lost in transmission hell"

True, i agree with you also

if someone was to be able to use LT1Edit to boost line pressure where it was needed where the stock programming fails, of course the v-mod wouldn't be needed

but not everyone can do that or understand it so that is why they bring transmissions to trans guys http://web.camaross.com/bb/wink.gif

so for those that cant figure out how to keep an OBD I tranny from failing, then do the v-mod.

can we agree on that? http://web.camaross.com/bb/wink.gif

Ellis, didn't you have to convert to ODBII to fix ur problem? (or so I recall on the old LT1edit topica archive)

89ProchargedROC -

No offense, just to clarify: nobody said anything about burning up trannies, so I don't know why you keep going off on that tangent. There is a well known problem with high-stall OBDI cars when the RPM's rise too fast. According to the logs people have posted, the VSS goes nuts and reads like 3 MPH which won't allow it to shift into 2nd... then when you let off, it figures out the correct speed, shifts into third, and stays there until you turn off the car.

Personally I haven't had the problem but I have a pretty tight 10" stall.

Does this have anything to do with the computer trying to detect a wheel spin condition(via being in gear and the RPM delta over a trigger). Sound like a fail safe to prevent from shifting during massive spin.

Or is it a sensor fault?

I can totaly agree Iroc http://web.camaross.com/bb/wink.gif

Yes we had to go to a OBD-II PCM to get a WOT 1-2 shift with a 4,000+ Convertor. Reason is know known and many are looking for a fix. I may toss may old OBD_I PCM back in and try a few different flashes to see what is up.

I am Now wondering if it may be everyone used a HPP+? and it changed the TQ model for stall Vs output speed.

Some day we will know I hope http://web.camaross.com/bb/wink.gif

Ellis

<font face="Verdana, Arial" size="2">Originally posted by 89ProchargedROC:
uh...not to be a smartazz but like i said, the reason why everyone blows their trannies with stalls any higher is because small diameter converters like the yanks and vigs' create TONS AND TONS OF HEAT, more than most realize.

</font>

Where, oh, where did I say anything about burning up a tranny?? I was talking about the famous non-1-2shift @ WOT.

boy o boy...try to give some people some information and they yell at you http://web.camaross.com/bb/rolleyes.gif

all i was trying to say is that....ah forget it

<font face="Verdana, Arial" size="2">Originally posted by 89ProchargedROC:
all i was trying to say is that.... </font>

heat burns tranny's up. Yes we know this, but what does this have to do with any stall above 3200 with an obd1 pcm not shifting from 1-2 @wot?? But if you use a 3000 stall, the tranny will work fine.

It sounds as though two solutions have been found, the vacum modulator or go to OBDII. But that is only if you have the problem. I have a 3200 stall and OBDI for over a year and have never had that problem.

<font face="Verdana, Arial" size="2">Originally posted by a_z28_vance:
...if you use a 3000 stall, the tranny will work fine. </font>

Boy, I hope so. I've got a 3000 stall waiting to be installed. Anybody here have a problem with a 3000 stall Vigilante?

-Chris



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'95Z: Black; stock except for all the aftermarket stuff;
12.72 @ 109.84
'01 S10 Xtreme:White extended cab, 2.2L automatic; more stock than Wall Street.

Feel the Quickness (http://www.fbody.com/members/Chrisbequick/index.htm)

The more I learn about women, the better I like my car.

94Red the Vacuum Modulator does not fix this particular problem. There is another choice but it included a modified valve body that you have to manually shift. The OBD-II PCM is the only know fix(IF you encounter this problem) that will let the car shift automaticly http://web.camaross.com/bb/wink.gif

We are hoping to find a solution for the OBD-I pcm but do not have enough people NOT having the problem to find a solution http://web.camaross.com/bb/wink.gif

Good luck all!

------------------
11 Seconds to LOVE!
Mod's? A little of this and some of that.
Beware of what you can not see
My Ugly Old Ride (http://www.teamnwfbody.org/TeamMembers/EllisGroo.html)
REAL racers Site (http://www.teamnwfbody.org)

If the problem is the pcm not keeping up with the fast rise in rpm due to a high stall, then I don't see why the vacum modulator would not work. I think there are some who disagree with you as well. And the state of understanding the way the pcm functions is still in the hacking stage. Just read the lt1 edit archives and find out that there is not even agrement about how the VE tables work. Everybody is still just poking around with it, tweaking until they get something close. That's fine with me, if it works it works, but those who profess to "know" can't seem to get repeatable results with all cars.

Well Red as the Guys who came up with the fix I am more then willing to set you straight.

First, the ONLY thing the V-Mod contols is line Pressure. The only thing this has to do with shifting is to make sure you have enough pressure to apply the clutches properly. It does a fine job of this when tuning is not used.

Second, the main problem is that the signal is NOT being sent from the PCm to the transmission. If you never tell the trans to shift how is raising the line pressure going to make it happen? You could raise it through the roof but if you never tell it to shift you might as well shoot it.

The area we were having wear on the trans was from going from a 3.06 first gear to a 1 to 1 third gear at to slow a speed. just before the 60ft we would have to lift and nail it again to get third. so now we are appling 500+ TQ through a 2.7 STR(1350TQ) to a clucth pack that was not ready for it. oddly enough it kept living http://web.camaross.com/bb/wink.gif

In the end what it came down to was we could not force the PCM to make the shift no matter what we did. I ask Ed if he could help and in the beginning he thought he had it handled. this was good for people who did not want to use LT1 Edit as he scrambles the file so you can not use Edit on it. For the rest of us we had to keep plugging away. I gave up on OBD-I in the pits at a race in between rounds in Canada. we swapped my car over so I could race.. I have not had any problems since then. The car actually drives better now then it ever has and the trans mission seams to be more acurate then it ever was with shifting. Only thing we lost is WOT lock-up and I think that is tied to the missing crank sensor. I am sure we will find a fix for that also http://web.camaross.com/bb/wink.gif

If you have any more Questions feel free to ask. I am sure any of the skilled Transmission technitions here will be willing to help you in your quest. I am sure they will also tell you if you never send a signal to the trans to make a shift it is hard for the transmission it self to make the shift http://web.camaross.com/bb/wink.gif

Later



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11 Seconds to LOVE!
Mod's? A little of this and some of that.
Beware of what you can not see
My Ugly Old Ride (http://www.teamnwfbody.org/TeamMembers/EllisGroo.html)
REAL racers Site (http://www.teamnwfbody.org)

OneFlyn95z28, on a similar topic...
Did you see this on the LT1edit list

<font face="Verdana, Arial" size="2">
It seems I have the feel of slippage after a 2-1 kickdown that doesn't
occur when pulling HARD after starting in first. I've always noticed this
"pressure up" time for a high stall on kickdown (you know the feeling of
needing to spool up) but I think I'm ready to figure it out.

Thanks,

_CAL
</font>

I know that most are tuning for the street so kickdown isn't a concern. This is on a 96z,Vig3600stall(4200 really) and P1s-c,8psi/2ic setup.

Any clues?

_CAL

I would bet you are feeling the slip of the stall convertor. I play with mine all the time. hard to get used to. goes against my grain to hold it in the TQ band while it feels like it is slipping but it sure pulls hard and does not spin the tires http://web.camaross.com/bb/wink.gif

On a up shift you are usually over the stall range but on a KD many time you go straight into stall http://web.camaross.com/bb/wink.gif

Good luck!

BTW Many time lately I have just hitting Delete on the LT list. to much stuff not enough time http://web.camaross.com/bb/wink.gif

Ellis

Thanks, not a big problem (been that way for 5 years http://web.camaross.com/bb/smile.gif

-CAL

OK, so there are two different problems. I should have read the previous posts more carefully.
But not everybody with OBDI and a high stall experiences the shifting problem. My stall is rated at 3200 but when I mash it it stalls at 4500. So it is plenty high enough stall to experience the problem if it is a systematic problem, you know, something inherent that will always show up. But I have never experienced any problems shifting under wot.
So I am skeptical about this "problem". Especially when it involves hacking into code that nobody outside of GM completely understands. You may have made a problem go away that you were experiencing with your setup, but you may not really know why, or all of the implications. You may have created a problem that hasn't shown up yet. Or maybe not. It is great that you are happy with your setup now. But I think a large dose of skepticism is necessary when hacking into the pcm that has functions that none of us outside GM fully understand. That's how people can go around fixing problems that they may have created in the first place. ;D

Then again Red if we fell into that type of thinking we would never do any thing to our cars(What the dealer and GM Want's).

You see every aspect of our cars is controled by the PCM. To do ANYTHING to our cars would violate this perfect world it lives in and cause problems. So in essance yes IF i had never added gears,convertor or any other numbers of things to my car I would not have to "Hack" the code.

Then again it would be a very boring world http://web.camaross.com/bb/wink.gif

Good luck!

How much is involved in swapping to the OBD2 system?

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Vigilante 3200 Stall Converter, LS1 Driveshaft, B&M Supercooler 19,000 GVW, Moroso Cold Air Induction, MAF Translator Plus, LT4 KM, Fan Switch, Jet IAT, Hypertech Power Stat, MSD Coil, NGK TR6 Plugs, Jacobs Wires, Russell Wire Dividers, Scanmaster, 3.23 Gears, SLP Headers w/PBM Coating, Borla Adj Catback, Air Foil, NX System, Nitto drag radials, Hal rear shocks, BMR STB PHR LCA

Ellis buddy, I'm not saying don't do it, and I have done a fair amount myself. I guess I am just a bit more carefull about calling a problem solved when there are so many unknowns. But if it works (for now) and you are happy with it, then you're in tall clover.

Ok, I'm ready to do the obd2 conversion. Has anyone here done it on a '94 and exactly what wire would I have to run to the new diagnostic connector? Hope I have this right. I have to get an obd2 computer, 95+ diagnostic connector, obd2 knock module, and of course the wire I'm supposed to run from somewhere to somewhere else...anything else I'm missing?

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94 Z28 auto.White with white wheels.A few mods. 12.01 @113.5 N/A with a 1.67 60' on bfgs

Too bad there's now way to make your car operate like 93 with a non-electric transmission. Or is there?

Apparently they don't have this problem.

------------------
'93 Camaro Z28 Automatic with a ZL1 hood.

No bottle.
No blower.
383 cubic inch serving of horsepower...hold the rice please.

Thats all you need to know.
ICQ: 23984221
Gripenfelter's Homepage (http://pages.sprint.ca/Gripenfelter)

Disclaimer: The opinions expressed by me are not necessarily supported or indicative of the Government of Canada or any other Federal Employee.

I saw in the posts above that it was recommended to run the vacuum modulator in blower cars.

How do you do that??

So far, my transmission is holding 437hp at the wheels. Some good parts, and I bumped up the part throttle line and temp settings with the LT-1 editor.

As far as the original question goes, can't you, with the LT-1 editor, just reduce the shift point mph on the 1 - 2 shift while keeping the shift rpm up where you want the shift to actually occur, I thought that PCM needed to satisfy both conditions before the shift would take place.

LWM

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95 A4, SLP catback, KBDD sfc, airfoil, Vortech S-trim, 30# SVO injectors, Autometer electric FP guage, boost guage, Hotchkis STB, AS&M headers, AFPR, Vortech Aftercooler, 3.125" blower pulley, 7" crank pulley, Vigilante 2,800 stall, MSD 6 BTM, SLP 35mm front bar, SLP 21mm rear bar, LT-1 editor ... :), 437hp at the wheels. --- members.shaw.ca/mackenzl/LWMsZ-28/LWMsZ-28.html (http://members.shaw.ca/mackenzl/LWMsZ-28/LWMsZ-28.html) ... 01 vert in the making ...

Oh yes the dreaded OBD1 high stall shifting problem. I fought this stupid thing for two years until Ed recently found a fix for it.

It is completely off the wall, affects maybe 1 out of 20 cars. The ONLY fix for it is in the PCM, a vacuum module will do nothing.

Ed can now fix it (unless you have 3.42 gears) and I believe Bryan Herter has now caught on as well. It takes some trickery to get it to work but it does.

Talk to Ed or Bryan they know all the details.

My car didn't shift right for two years and now bangs off every gear even with my 4,100 Vigilante http://web.camaross.com/bb/smile.gif

-Andy

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1995 Impala SS (http://4drss.cz28.com/index.html)
12.45 @105.51
Stock shortblock, no power adders, and full weight.

How recently did he find this fix? He tried programming mine back in January but it still didn't work.

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94 Z28 auto.White with white wheels.A few mods. 12.01 @113.5 N/A with a 1.67 60' on bfgs

My car did it with the 2800. So i didnt bother putting it back in. So know with the new tranny i can put the 3200 back in. http://web.camaross.com/bb/wink.gif What does ed charge for it 4DRSS?

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Vigilante 3200 Stall Converter, LS1 Driveshaft, B&M Supercooler 19,000 GVW, Moroso Cold Air Induction, MAF Translator Plus, LT4 KM, Fan Switch, Jet IAT, Hypertech Power Stat, MSD Coil, NGK TR6 Plugs, Jacobs Wires, Russell Wire Dividers, Scanmaster, 3.23 Gears, SLP Headers w/PBM Coating, Borla Adj Catback, Air Foil, NX System, Nitto drag radials, Hal rear shocks, BMR STB PHR LCA

<font face="Verdana, Arial" size="2">Originally posted by big dave:
How recently did he find this fix? He tried programming mine back in January but it still didn't work.

</font>

Dave he got it working the mid/end of March. Look him back up, he's got some new tricks up his sleeve http://web.camaross.com/bb/wink.gif

<font face="Verdana, Arial" size="2">Originally posted by chevy94c:
What does ed charge for it 4DRSS?

</font>

Check for yourself at http://www.fastchip.com/

I guess I'm just simple, but why not run a manual valve body? So you shift the car yourself, big deal. No problem with stall speed, and more control over when the car shifts. I really like the manual valve body and the B&M Pro Ratchet is great. It is like having a manual without the clutch. I get the best of both worlds. http://web.camaross.com/bb/smile.gif

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'94 Black Z28, 383, 700R4
1/8 ET: 7.49
1/4 ET: 11.86
1/4 MPH: 112
http://www.downtime.cz28.com.index.html (http://www.downtime.cz28.com/index.html)

<font face="Verdana, Arial" size="2">Originally posted by tnthub:
I guess I'm just simple, but why not run a manual valve body? So you shift the car yourself, big deal. No problem with stall speed, and more control over when the car shifts. I really like the manual valve body and the B&M Pro Ratchet is great. It is like having a manual without the clutch. I get the best of both worlds. http://web.camaross.com/bb/smile.gif

</font>

You obviously don't have a granny column shifter like I do http://web.camaross.com/bb/wink.gif Shifting manually on the tree is out of the question for me. A console shifter like the F-bodies maybe, but not in an Impy. You don't know how many shifts I missed shifting manually before I got this fixed.

Call me lazy but I just want to mash the gas and GO! http://web.camaross.com/bb/biggrin.gif



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1995 Impala SS (http://4drss.cz28.com/index.html)
12.45 @105.51
Stock shortblock, no power adders, and full weight.

<font face="Verdana, Arial" size="2">Originally posted by 4DRSS:
You obviously don't have a granny column shifter like I do http://web.camaross.com/bb/wink.gif Shifting manually on the tree is out of the question for me. A console shifter like the F-bodies maybe, but not in an Impy. You don't know how many shifts I missed shifting manually before I got this fixed.</font>
Should've gotten a '96 http://web.camaross.com/bb/wink.gif http://web.camaross.com/bb/rolleyes.gif

<font face="Verdana, Arial" size="2">Call me lazy but I just want to mash the gas and GO! http://web.camaross.com/bb/biggrin.gif</font>
Hey Andy, YOU'RE LAZY!!! http://web.camaross.com/bb/tongue.gif http://web.camaross.com/bb/tongue.gif

Just kiddin, man http://web.camaross.com/bb/biggrin.gif Your SS is bad ass http://web.camaross.com/bb/cool.gif

------------------
Cheston P - IM_A_0@yahoo.com AIM:Impalaitis
96 BBB Impala SS "ADIOSS"
91 white Caprice 'n0n 9c1' w/L03

GM_TBI listserv (http://groups.yahoo.com/group/GM_TBI)
GMForums.com (http://discussions.gmforums.com/)
ImpalaSSForum.com (http://www.impalassforum.com/)

[This message has been edited by AdioSS (edited April 25, 2002).]

Yeah lazy!...Oh wait so am I http://web.camaross.com/bb/wink.gif

Besides it is more consistant for me http://web.camaross.com/bb/wink.gif

------------------
Ellis
Project "Dementia" now under way!

O.k., I have been carefully reading this thread.

My car is fine w/ the 2800 Vigi. I have a chance to go up to the 3800 Vigi. But after reading all this, I am afraid to. I have
a 95 that is OBDI as well.

So, would I have to do this vaccum MOD or not? Or would the programming ED would do FIX it? And I wouldn't have to worry about burning up the tranny???

What is the straight answer on this? Thanks for the help....

Spoke to Ed a couple days ago. I was told that there isn't any surefire obd1 fix. His programming might work on some cars but others it won't. He said since his programming didn't work on mine before nothing has changed that would make it work now. Oh well, I guess I have no choice but to wait it out or just go to obd2.

Well, I am not switching over to OBDII. I like how my scanmaster works!

So, I think I will wait it out.

Ed told me the same thing.

Thanks

Its not just a stall rating, its also how hard you hit the tires. Dave just get eht tranny controller!

Yup so far only SURE fix is to go to OBD-II.

I am going to shoot for high 9s with it http://web.camaross.com/bb/wink.gif

------------------
Ellis
Project "Dementia" now under way!

I definitely want the tranny controller but I've got other problems to take care of first so it may be gone by then.

------------------
94 Z28 auto.White with white wheels.A few mods. 12.01 @113.5 N/A with a 1.67 60' on bfgs

Well I was talkin to my buddy Ryan (AHARTZ28) and he said he was an A4 with a 4400 stall. I said oh so your obd2 and he said no obd1. So he said he got around the 'infamous' problem by doing this:

<font face="Verdana, Arial" size="2">Set your RPMS for the shift at 1200 then set a MPH whatever you want make sure it is well below the rev limiter it takes about 600 rpms sometimes to shift completely maybe more you have to test it a bunch of times to get it right, that way it clears the RPM flag right away an only looks for the MPH.</font>

Anyone have comments?

I am STILL looking for some one to test new ideas to fix this http://web.camaross.com/bb/wink.gif

Ken yes that seems to be a hit and miss way. We tried it but it did not Always work http://web.camaross.com/bb/wink.gif

------------------
Ellis
Team Captain
Team North West F-Body
www.teamnwfbody.org (http://www.teamnwfbody.org)

<font face="Verdana, Arial" size="2">Originally posted by LTOne4Fun:
Its not just a stall rating, its also how hard you hit the tires. Dave just get eht tranny controller!</font>

I have to agree here. Now, I am no advanced tech expert, actually those here that know me know I am a newbie but here is what i experienced:

My best 60' is in the sig.

A couple of weeks ago I was running at Woodburn, OR. Hoosier QTP's at 12 lbs. Stage up, go! Car hooked hard. A buddy of mine was at the rear of my car in the staging area. He told me the car hooked hard.

I get to my 1-2 shift point, it keeps going and I hit the rev limiter. I back out, it shifts. I throttle, car backfires big time with a large cloud of black smoke, according to my buddy.

I roll back into throttle kinda wondering if I messed something up ended up rolling back to WOT with a run of 13.1 @ 107mph.

Get back to staging lanes car is stuck in third gear. Turn car off and the tranny resumes normal operation. I did not run it anymore that day and have not run it since. This happened with a 2800 vigilante.

Hope to run it again here soon in the cooler fall weather looking for 11's.

By the way this launch was a 1.71 60' But it really hooked hard. You all know how you can tell when it hooks!

Ellis I wil discuss this with ya on IM.

Ken



------------------
95 Z28, BBK 52 mm throttle body, ported MAF ends, K&N CAI, ASP Pulleys, 160 thermostat, PCM by WWW.PCMFORLESS, (http://WWW.PCMFORLESS,) LT4 KM, Heads by WWW.flow-technics.com, (http://WWW.flow-technics.com,) 2.055 int/1.57 exh. valves, 1.6 RR's, CC XE 230/236 544/556 112 LSA, Comp "R" lifters, Comp Magnum pushrods, FMS 24# SVO injectors, Meziere WP, Jet Hot coated Hooker LT's, Flowmaster cat back exh., PI Vig 2800-3000 TC, Strange 3.73 gears. Dyno numbers to come soon.

60' 1.690
1/8 7.674
MPH trap broke
1/4 12.059
MPH 113.00

My car www.teamnwfbody.org/members/mcdonald.htm (http://www.teamnwfbody.org/members/mcdonald.htm)

VID: CCXE230/236 thru Hooker LT's (http://members.shaw.ca/jd30thz28/KenS.MPG)

I know that one day Ed Wright or someone will figure the cause of this "no 1-2 shift limp mode upon hard launch" I hope so.

Let me add my experience to this thread.
I've had the no 1-2 shift -&gt; limp to 3rd gear happen many times over the last 7 years in my 95 impala SS.

The 1st time this happened was when my tranny was nearing end of life, (about 4 year old tranny with 300 mild 1/4 runs). I did not have a high stall converter and the car only went low 14's. I think I loaded up on the converter at the starting line. If I remember correctly, 2000 rpm or so. 60' times were probably only 1.9 to 2.0 The air was very cold too. Then someone told me to start the 1/4 run in manual 1 and to my suprise, the tranny shifted perfectly.

Since then I've had a 4000 stall Vigilante behind a 383LT1 natural. Never had the no shift problem. But I quit loading up the converter at the starting line. I launch from a tick off idle all the time now. Tranny always shifted perfectly accept when it was cold I would get a 2-3 flair up.

Now just last year I removed my 383 for the winter and put in a very mildly cammed 350LT1 and went to Cecil on a freezing cold day to try for some record ET's in the impala world. I wasn't bracket racing so I shallow staged and loaded up on the converter, (also starting in manual 1), and low and behold, no 1-2 shift --&gt; direct to 3rd gear limp. I actually thought that I was too slow on the 1-2 shift and that it was my fault and I simply hit the rev limiter so I return for the 2nd attempt and am concentrating on being quick with my manual shift into 2nd gear. I loaded up the converter, (gives me a quicker ET), and launched and make the shift before my shift light but BAM---NO 1-2 --&gt; directly to 3rd gear limp. I quit for the day.
Then it dawned on me...I had quit loading up the converter and now I'm back to loading up the converter and now I'm not getting the shift.
2 weeks later I drove with that same tranny down to Florida and launched just off idle, (warm air), and had perfect shifts.

I think that the problem could possibly be a some sort of torque converter slippage protection, and not VSS related. Whatever. I do know how to NOT get the no 1-2. I always launch from near idle. Never load up on the converter. Remember, this is in a heavy car with a 4000 vigi. (no heat problems here either and no tranny problems out of the ordinary).

Hope this adds info for you guys to figure the problem out. I've got Ed Wright tuning and I'm hoping that I'm the first to get the code fix on this if Ed or you guys nuke it out.

Karl Ellwein, 95 Impala SS, Ed Wright tuning,
12.38 @ 110 with Natural 350LT1, ARE Heads, Crane 227 cam
12.15 @ 112 with Natural 383LT1, ARE Heads, Solid Roller cam

Yep I load the TC to 1800-2000 on launch!

I will try from just above idle next time. 1100-1200 rpm's.

Another thought. Does everyone who has this problem run DR's or slicks? Or do some run regular street tires and get the same 1-2 miss

Ken

------------------
95 Z28, BBK 52 mm throttle body, ported MAF ends, K&N CAI, ASP Pulleys, 160 thermostat, PCM by WWW.PCMFORLESS, (http://WWW.PCMFORLESS,) LT4 KM, Heads by WWW.flow-technics.com, (http://WWW.flow-technics.com,) 2.055 int/1.57 exh. valves, 1.6 RR's, CC XE 230/236 544/556 112 LSA, Comp "R" lifters, Comp Magnum pushrods, FMS 24# SVO injectors, Meziere WP, Jet Hot coated Hooker LT's, Flowmaster cat back exh., PI Vig 2800-3000 TC, Strange 3.73 gears. Dyno numbers to come soon.

60' 1.690
1/8 7.674
MPH trap broke
1/4 12.059
MPH 113.00

My car www.teamnwfbody.org/members/mcdonald.htm (http://www.teamnwfbody.org/members/mcdonald.htm)

VID: CCXE230/236 thru Hooker LT's (http://members.shaw.ca/jd30thz28/KenS.MPG)

Yes most of the people who have REALY had this problem and looked into it agree it is a TC Slip table Vs VSS and not a VSS issue http://web.camaross.com/bb/wink.gif

Ken I will mod you file and next time you are up we will load it http://web.camaross.com/bb/wink.gif

------------------
Ellis
Team Captain
Team North West F-Body
www.teamnwfbody.org (http://www.teamnwfbody.org)

that all makes sense, but what is the difference in the programming in obd2 pcms that cure this? is it in the tranny tables that control the pressure regulator
?

<font face="Verdana, Arial" size="2">Originally posted by slowpoke96z28:
that all makes sense, but what is the difference in the programming in obd2 pcms that cure this? is it in the tranny tables that control the pressure regulator
?</font>

Very good question and hopefully someone will figure out the answer. If you do, please don't keep it a secret. http://web.camaross.com/bb/smile.gif
I'm going to visit my buddy Ed Wright October 2nd and 3rd and I'll be absorbing some tid bits of wisdom. I'll see what he has been up to on this deal.

Karl Ellwein, 95 impala SS

Who here that didnt have the problem ran some kind of shift kit, and if so what kit?

Transgo makes an add on to there kit that makes 4l60e's full manual valve body with the flip of a switch and then back to fully automatic when flipping it back. I put it in my trans and love it. I was having the skip shift problem and now when I want ot change shift points I don't have to get the laptop out just do it manually. On nitrous I like to short shift it a little too so I don't have to worry about anything just my shifting abilties which are pretty good I must say.

------------------
1995 T/A RamAir,17x9 WS6 polished rims,A4 Transgo 3:42's,LT4 Hotcam kit, mildly ported heads and intake, built 355 with forged pistons, LT4KM,NX N20 kit 125-175hp, Custom programming, AS&M headers, Vigilante 2800,
flowmaster catback, Fernco intake bellow,CSI w/p,MSD 6al, cutout. Everyday driver. New Et 12.50@107 N/A
11.61@117mph on N20. 1st decent N20 pass more to come!

This subject seems to be coming up quite frequently lately, hopefully this tread will be of some help.

We have some people on it now. We will see how it comes out ;)

I posted here too since I believe that this is realted to several other posts.
I thought I had my tranny fixed but nogo!!!!!!
The tranny works fine as long as I dont load up the Torque convertor. Just leave the light and hammer it I get good shifts. I went to the track today to try my new trans. I loaded up the torque convertor nailled it on the bottom yellow, shift light came on at 6100 made shift bam no 1-2 shift let off and tranny goes into 3rd gear limp mode. tried lowering mph some more and shift rpm to 5500 and still no 1-2 shift. Bummer!!!!!!!!!!!!!!!!

Has anyone found a fix or isolated the problem. Is it related to the VSS and convertor slippage? Has anyone been able to compare the tables between to obd1 and 2 files.
and what is entailed in swapping a 95 to obd2 since this seems to be the only fix

2 choices. Either switch over to obd2 or do as I did, convert over to a 700R4. My converter doesn't lock up when it should so I've lost a mph or 2 but I no longer have the shifting problem. Once I get a manual lockup switch, everything should be fine.

Ed Write now has the fix. he found the table. It is set from the factory at 2,400 stall. Any stall over that with less then XXMPH showing sets it in limp mode.

I am switching back to OBD-I to verify and get my WOT Lock-up back!!

www.fastchip.com

Tell Ed, Ellis Sent you!

Originally posted by OneFlyn95z28
Ed Write now has the fix. he found the table. It is set from the factory at 2,400 stall. Any stall over that with less then XXMPH showing sets it in limp mode.

I am switching back to OBD-I to verify and get my WOT Lock-up back!!

www.fastchip.com

Tell Ed, Ellis Sent you!

Please post the results of this. I would love to run a 3600 stalled converter on my 94 obd1 z-28.

I will let you know how it works with my 3,800+ Yank.

Looks like My next race is a month away. I will see if I can sneek off to a test and tune.

NO I can not share the file. You will have to call Ed.

Originally posted by OneFlyn95z28
I will let you know how it works with my 3,800+ Yank.

Looks like My next race is a month away. I will see if I can sneek off to a test and tune.

NO I can not share the file. You will have to call Ed.

Id figure you would say that but I understand. Let us know:)

I run a yank 3500 And have yet to have this problem with my 1/2 shift, mabye it has something to do with the type-f Tranny fluid yank told me to use?? I havent tried slicks yet...

Originally posted by Dave Feerst
I run a yank 3500 And have yet to have this problem with my 1/2 shift, mabye it has something to do with the type-f Tranny fluid yank told me to use?? I havent tried slicks yet...

Thats when it usually happens bro. When you get your tires to really hook is when this problem usually happens. Put some et streets on that bad boy and launch her and see what ahppens:)

EWWWWW! Type-F! ICK!

The problem usually happens with good hard launches when the foot stall is over 2,400 at the line and the flash is hard.

BTW Saying type-f is the fix to this problem is like saying exlax will clean out your vanes during a heart attack ;)

Good luck!

Any tuners found anything to resolve this, i know Ed Wright found the fix but not a fan mail order tuning. Anybody?.......Bueller:)

Call Ed. He may suprise you. You can get JUST this fix.

Went to Ed's shop mid July and learned about the fix. Simple computer code fix just like Ellis mentioned.
I have it now but am too chicken to launch off idle to give it a real life test. I'm so used to launching from idle I couldn't imagine doing it any other way.
One thing baffles Ed and I though. My tranny will now short shift 2nd gear and go to 3rd before the programmed rpm, (If I launch from D or OD and let the tranny do the shifting). I must hold 2nd gear manually until it's time for 3rd gear.
So I have the fix, but havn't tested yet with a loaded up torque converter launch. And, I now need to hold 2nd gear manually untill it's time for 3rd, (when at WOT at the track....untested on the street).
All this experimenting was done at the wrong time though. 1st round of an important bracket race, with Ed watching at the starting line, he's talking to GMHT Performance editor Rick Jensen and saying every good thing about me that he can think of, and I go and launch and the car short shifts into 3rd gear and I run a 12.8 on a 12.3 dial. 1st round looser. D*oh!
That's ok, he and I figured I could manually shift later that night and the car became very consistant.
I think it may be my tranny's fault and not the fault of the code fix.
Karl

Originally posted by OneFlyn95z28
Call Ed. He may suprise you. You can get JUST this fix.

come again Ellis:confused:

He wouldn't sell me just the fix:cry:, Period.
Had to buy the tuning with it and that would be fine but for me that means throw'n away ton's of hours with wide0'2 logging for open loop leaded fuel tune.:cry:
Then my LT1 edit licence would be like my fingers typing this...
.........shoved into fan blades:rolleyes:

Nothing against fastchips tho, they have every right to control "Their Product's" use and distrubtion.
I'll just wait for Yanks Tranny tricker I guess and go electric manual valve body control.
:sigh:

Originally posted by Hot Rod Hawk
come again Ellis:confused:

He wouldn't sell me just the fix:cry:, Period.
Had to buy the tuning with it and that would be fine but for me that means throw'n away ton's of hours with wide0'2 logging for open loop leaded fuel tune.:cry:
Then my LT1 edit licence would be like my fingers typing this...
.........shoved into fan blades:rolleyes:

Nothing against fastchips tho, they have every right to control "Their Product's" use and distrubtion.
I'll just wait for Yanks Tranny tricker I guess and go electric manual valve body control.
:sigh:

So how much is it for the whole package with the fix?

Originally posted by OneFlyn95z28
Ed Write now has the fix. he found the table. It is set from the factory at 2,400 stall. Any stall over that with less then XXMPH showing sets it in limp mode.

I am switching back to OBD-I to verify and get my WOT Lock-up back!!

www.fastchip.com

Tell Ed, Ellis Sent you!
i would get in touch with Bryan at pcms for less he has the fix ;) i had it bad with mine and he fixed it...........for free too ;)

Originally posted by MEAN LT1
So how much is it for the whole package with the fix?
E-mail ed wright at fast chips for your quote.
One other thing to remember is that if you have Lt-1 Edit for the pcm you send him you no longer will be able to use your owned copy of LT1 edit on that pcm. Ed protects his tunes by moving code locations to differant locations within the deal, That is a smart thing to do on his part!.
Good Luck.

Originally posted by Hot Rod Hawk
E-mail ed wright at fast chips for your quote.
One other thing to remember is that if you have Lt-1 Edit for the pcm you send him you no longer will be able to use your owned copy of LT1 edit on that pcm. Ed protects his tunes by moving code locations to differant locations within the deal, That is a smart thing to do on his part!.
Good Luck.

Well, guess I'll be going to pcm4 less unless some local tuner here in florida figure it out.:)

LOL You mean until they steal Ed's fix!

Some of the best tuning out of local guys came out of Ed's shop ;)

At least I have the balls to tell them I am ordering it from Ed's when I need it ;)


I have the "FIX" and a OBD-I PCM back in my car. Need to finish the tuning and I will be headed to the track for some real world testing.

Just in case I and taking my OBD-II PCM to back me up ;)

Originally posted by OneFlyn95z28
LOL You mean until they steal Ed's fix!

Some of the best tuning out of local guys came out of Ed's shop ;)

At least I have the balls to tell them I am ordering it from Ed's when I need it ;)


I have the "FIX" and a OBD-I PCM back in my car. Need to finish the tuning and I will be headed to the track for some real world testing.

Just in case I and taking my OBD-II PCM to back me up ;) actually Bryan came up with it, ED may have gotten it from him ;)

I am pretty sure that is not true ;)

Originally posted by OneFlyn95z28
I am pretty sure that is not true ;) well when i had my stall problem i contacted Ed wright about it he said the fix he had was still giving poeple problems he originally did my programming,and it worked only with some cars.then i got LT1 edit then i got ahold of Bryan and he emailed me the fix and has worked every since then..they were both working on it together i belive for awhile...

Originally posted by AHARTZ28
well when i had my stall problem i contacted Ed wright about it he said the fix he had was still giving poeple problems he originally did my programming,and it worked only with some cars.then i got LT1 edit then i got ahold of Bryan and he emailed me the fix and has worked every since then..they were both working on it together i belive for awhile...

Well being that my car already has tuning done to it and I dont want it to be locked from. I think Im going with Byran just for the simple case that he doesnt lock me out of my own pcm.

Originally posted by Hot Rod Hawk
Ed protects his tunes by moving code locations to differant locations within the deal, That is a smart thing to do on his part!.
Good Luck.

No it's not. It's bullsh!t. That's my pcm and I'm paying him to write a program for my car...then that tune belongs to me, I bought it. All of this locking and anti-tampering is crap. :rolleyes:

I did not know that Bry had a fix until I read this thread.
Bry has been a good friend for many years and Ed has been a long distance friend and partner of mine for many years.
I was suprised that I didn't know about Bry's fix.
Just spoke to Bry face to face yesterday. I said, "Bry, I didn't know you had a no-1-2-shift fix. I heard it on camaraoz28.com".
Bry said he had a fix but it's not a code fix, it's a work around with shift points, etc. And if it works, it works. That's good for us OBD 1 guys.

Now honestly, Ed's fix is in the actual GM code that causes the limp mode exactly as Ellis described. This is recent, less than a few months. It's good stuff to have the actual code fix and I hope the OBD 1 world can bennefit from it somehow.

And by the way, I did not test my application yesterday. Bry and I were racing heads up in our impala es eses. I had no opportunity to try a loaded up toque convereter launch. (But my launches from idle are dang hard enough for my taste with 1.69 60' in a 4000 lb boat.)

Karl

Hehehe. MY old fix ;)

I had so so luck with it. Worked on some cars did not on others. I tried a PCM of his last month in my car and I was still having the problem.

Ed Found the Table that was actually setting the problem in motion. Hopfully tomorrow I will get to finsh modifing the file with my last tune and can give it a try at the track next race.

good luck all!

Is Bryan @ pcm4less out of town??? I need this fix and emailed him a week ago with no response. Thanks Steven

thanks for all the input everyone
I'm running a vigilante 0 (~2800) currently but thinking it won't be enough for the new engine
it's either fix the 1-2/limp problem or build a 200-4R :cool: (or should I say another 200 lol)

Originally posted by triumph
Is Bryan @ pcm4less out of town??? I need this fix and emailed him a week ago with no response. Thanks Steven
Bry should be home. Give him another email
Karl

Originally posted by triumph
Is Bryan @ pcm4less out of town??? I need this fix and emailed him a week ago with no response. Thanks Steven

Bryan emailed me back on August 3rd, verifying my order. He said he is waiting for some PCMs so he can send out my updated tune for my fuel curve and for my new 3200 stall. I'm hoping everything goes smoothly. Knowing Bryan, I'm sure it will :)

I had the shift problem for 4 months!! 3200 vig. Bryan tried to fix it with no luck. So I bought Tunercat and went to work on the trans tables. After several tries, I got it shifting beautifully. Under all conditions. Off idle, stalled up, nitrous launches etc.
I almost threw in the towel, But I'm glad I kept trying.

Originally posted by Z28ROC
I had the shift problem for 4 months!! 3200 vig. Bryan tried to fix it with no luck. So I bought Tunercat and went to work on the trans tables. After several tries, I got it shifting beautifully. Under all conditions. Off idle, stalled up, nitrous launches etc.
I almost threw in the towel, But I'm glad I kept trying.
wow, your car has come along way. I remember that video from like two years ago. I'llhave to keep you in mind. I have a 3400 stalled converter in my car now and want to get the pcm revised for this mod.
:)

Thanks. If you have the shift problem, just shoot me an email and I'll see what I can do.

Originally posted by Z28ROC
Thanks. If you have the shift problem, just shoot me an email and I'll see what I can do.

I was hoping you would say that. Im going to try nittos first and then Im going to try the et streets.:)