Remember me!?!

Well here I am, some history:

1993 T/A -Auto :Full Bolt-Ons, Ported LT1 Heads, XE230/236 112LSA Comp Cam, PCM4LESS tuning...........

Few points about the mods:
using Cloyes Double Roller, still have 3.23 rearend, 30# SVO injectors

....mustered all that might for a miserable 13.9 at 102mph (1/4).

Symptoms:
-No Power, low torque (hardly spins), dreadful topend.
-Make you CRY PIG RICH
-Extremely rough idle, like it is running on 5 cylinders- cannot maintain rpm
-fouls plugs in minutes, (they are full black when I take them out)
-Cylinder 1 Exhaust primary not as hot as others, will hardly boil sprayed water.
-stalls under load, and after WOT run.
-LT BLMS @ 108 (left and right) when in CLOSED LOOP.
-Low Vaccum (ranges between 7-9) inches, MAP readings confirm this. BAR = 30.30, MAP ranges 21-22.xx)
-Have failed Quad Drivers (1 and 3 specifically) - no definite answers of what they mean (have not replaced ECM)

What I have done:
New OPTI (installed correctly)
New Plugs, Coil, Coil Wire
New IAC, IAT, MAP, TP, 0'2's, Opti harness
converted to heated 02's
Checked for Vaccum Leaks - None
Checked for Spark at all wires - OK
Checked Fuel Pressure - OK remains steady at 43psi at WOT
Confirmed KNOCK RETARD - Nothing PRESENT "0"
Check Timing Chain Alignment, = it is perfect DOT to DOT, dowel at 3'Oclock, Crank keyway at 1.5 Oclock, used the correct keyway setting on the Cloyes (rounded top), and used the dot. DAD confirmed this too (remember engine assembled by reputable shop).

-tried running stock 22# injectors on 30#tuning, ran much better, but still rich, no power!!!

What NEXT!!!!!

 

Sounds like you got a bad tune. Did you happen to tell them how much fuel pressure you were running. 93 tuning sucks! Get a scan of all data and send your chip back to PCMforless and have them tune around your readings.

 

....or check your fuel pressure and play with an adjustable regulator to find a good pressure for the car.

 

QDM Failure does not always indicate an actual problem with the PCM. It is a "self protection" mode for the drivers in the PCM. What it means most often is a failure of a component connected to the PCM that does not have any other sort of monitoring (I.E. codes for that component) You need to find out if you have anything shorted connected to the PCM. I would start with those SVO injectors.

 

I would start by putting the stock chip and injectors back in and see how it runns. Not going to be the best with a cam due to speed density system but may help you go in the right direction.

It sounds like all thing be what they should you may need a chip. Get some one who knows what they are doing to take cars of it for you. At the shop we use Ed Write exclusivly. PCM4Less has most of there experiance on MAF cars which tune alot diferent then MAP system cars

Good luck man!

 

Wait a tick!!!! I'm having VERY similar problems, albeit not as bad. I'm running PIG rich, which is in turn causing me to stutter and hesitate down low. Keep us posted on this, as I will too. I'm running a 224/230, very nice ported heads, and 30# SVO's also. cloyes true roller, vented opti conversion, ect. Sound familiar???? I'm putting it on datamaster here a little later and will post my findings.

 

Atrayu!! Where are you!! Atrayu!!


btw, what exactly DOES "PIG" stand for in this context?

 

Pig= Extremely Fat ect ect.

 

Yeah, I know.. Just funny how people use animals or animal parts to describe their condition.... "pig", "bone", etc.

But when you think about it, Pigs only eat as much as they can handle. Now BIRDS on the other hand eat typically 3 times their weight each day. So how 'bout saying it like, "my car is running BIRD rich"....

Have a great day!!

 

reply to: OneFlyn95z28

I have tried running on stock tuning, with the stock 22# injectors, but it wont even turn on. As soon as I put the chip, it will fire right up the first time. If I leave it running for a few minutes, It gets more diffucult to turning it once again, like it is flooded with fuel, although if I a smash the gas pedal it will turn on (but I know that the ECM enters "CLEAR FLOOD MODE" when turning the ignition with the pedal pressed.

reply to dave1w41:

I have checked each injector and they do fire. I checked that with a noid light. Do you know how can I check if they are shorted?

reply to Fastbird93:

Is your car drastically down on power also? Has anyone with another 93 4thGen had a succesful vented opti conversion?

To ALL:

Tommorrow I will finish removing the intake manifold, my DAD is coming down and checking proper valve seal, and the relationship to valve position at the time each piston enters firing point. Basically we are going to compare the COMP CAM lobes positions to the stock cams we have. We will try to eliminate the possibility that this cam is ground incorrectly.

Thanks for all of your responses....

BTW my brothers 96Z just matched speed for speed a 2003 COBRA, I miss my old car.

 

No, my car actually runs like a raped ape when once it's broken through the stumble area, and that's still down some HP because it's so rich.

For the better part though, the symptoms sound the same. I'm wondering if it's an SVO 30# thing???

 

Well, I have checked everything mechanically with this car, the timing chain alignment is good, valve seal is good. I guess the problem is outside the engine afterall. Valves are adjusted properly, the only thing that had our attention is that when the rockers are fully relieved (valves closed) I can physically pivot the rocker back on against the lifter. Could this be because the lifters are bleeded, has been 1 month since I lasted fired it up, and two weeks since I bleed it of oil. I can pivot the rocker about 1/2 inch against the lifter, like they have no force. Is this a sign that the lifters are toast? They are new Comp Cam lifter (non Pro-Magnum, bought these when there was a shortage of the Pro-Magnum versions).

Thanks

 

you should not be able to move the rockers at all by hand. it sounds like either a lifter has colapsed or the rockers are not adjusted correctly. if you are actually pushing in the lifter by hand its junk. get new ones.

 

Red,

Ok, sounds interesting, let me clear this one up just one more time to see if I get this better. Just to make sure. Not that I doubt your knowledge, but just to make sure.

Assuming the rockers are adjusted correctly..........if I pivot the rocker back against the lifter on a valve that is fully closed (spring on rested position) by at least 1/2 inch, this could possibly mean that the lifters are bad. I can do it on all of them that are fully rested. So even if they are bleeded of oil over time (engine not fired in 1 month, oil drained out for 2 weeks) this should not happen. Right?

Just to point out, I originally bought Comp 987-16 springs (recommened by Thunder Racing), but the shop said they needed additional spring height. So I do not know what is in there right now, but they are similar, Dual Coil, with another small one inside. I believe they did this because of the 2.02 intake valves. But I dont know. Also, I never bouth Pro Magnum, (not available at the time).

Is there a good test for the lifters?

Thanks Red

 

just another reason i would never rely on a mail-order tune for anything besides bolt-ons.