LS1 bait

well i went to the track last night and 2 out of the 3 times i ran i hit the "wall" and the car would not shift into 2nd.both times it did it i dead hooked and had a 1.7 60 ft.the first time it spun a little and i had a 1.9 60 ft and it shifted fine.i already got a pcmforless program for my car but it didnt seem to work.does anyone know of any other solution to this problem besides switching over to odb-2??maybe disabling the speed sensor??

BTW--i have a 95 bolt on z28 with a 2800 stall.

funina91ss

did it go from 1st to 3rd? I think that is what happens to most people.I have a 3k stall and last time at the track my car wouldnt shift..out of probally 25-30 passes pulling 1.6X to .75 I hope it was just a one time thing. And I also heard stalling them up will make it happen more offten try leaving at 1k if you havent already.

FastZinTennessee

Oh sh*t now you guys are starting to scare me. I've got a midwest 2800 stall on the way, and I don't want to have any shifting problems!! BTW what shiftkit are you guys running?

John

big dave

My 94 has had the same problem. In fact, if you do a search, you'll find the tread I started on this same subject, there were quite a few responses. After trying different programs, I ended up going with a 700r4 tranny, now I get to shift when I want. Another one of your options will be to convert over to obd2 to combat this problem.

LS1 bait

my tranny is fairly new and my car has way too many miles to consider swapping it for a 700r4.looks like i may just never get a good time out of my car if those r my only 2 options.

Dan K

On the 3 cars that I've done by tricking the VSS, all shift just fine at whatever shift points I tell them to.

indy500ss

Wait, so let me get this right, if I have a700R4 in my car I shouldn't have any shifting problems with my OBD1, but if I were to have a 4L60E, then the problems would arise. If that is true I am in luck because I do have a 700R4. Guess it is time for me to order that SY3500!!!

transamtom

I thought the problem was only with a 3000 plus stall on OBD1 cars?

I have a 2800 and have had no problems with it shifting or with everyday driveability.

Maybe I got lucky?

LS1 bait

i would really liek to know how u did this because it would be nice to have a car that shifts at wot on a track.thats the onyl reason i got the converter i cant flash it on the street.

Kory 88 Iroc Lt-1

I have had problems not shifting into third at wot. I have a 3k midwest stall. I noticed this after I tried swapping my stock tb for a holley 58mm I bought. The holley messed up my shift points so I put the stocker back on. I went to the track the next day and on my second pass the car wouldn't shift into third. I finally let off the gas at 6600. Could my tps adjustment be at fault? The car shifts fine at all other speeds exept wot. Or is this a problem caused by the higher than stock stall?
Thanks,
Kory

Transamdriver

I have a 97' with the OBD-I conversion and a 3200 stall. I also have the PCMForless tuning and my car has never had the dreaded 1-2 shift problem. The only problem I have had is the car going into "limp" mode and starting out in 2nd gear.

rage366

i have a 3000 stall, and my car always started in second gear...but, then again, it only went to 3rd gear and didnt go to OD...but, that was a transmission problem...well, hopefully, that was all it was.

new tranny is coming and so is the new 3000 stall.

LS1 bait

there has to be a way of making these converters work in these cars.what is the difference between the vss in the 95 and 96 cars??is it the actual sensor thats different or the pcm??if its just the sensor will a 96 sensor work in a 95 car??

Dan K

Let me start by saying this does not work on all cars.
Also, if any of the information that I provide is inaccurate, please let me know.
The story that I heard was that with a converter that can provide a quick enough 60ft (it's not "3000rpm" and above converters) and a hard enough launch, the VSS gets confused and doesn't read mph correctly. Therefore when you hit your target shift mph the car won't shift since the VSS isn't reading mph correctly.
Remember what makes the car shift, the computer reads the kickdown mph and kickdown rpm. When both of these values are reached, the trans will shift.
So in order to trick the VSS and make the car get a 1-2 shift, you need to set the kickdown mph tables to shift at 1mph. It will then use the kickdown rpm tables in order to make its shift. Kind of like taking the VSS out of the equation on the 1-2 shift.
Short version, but you get the idea.
Can you figure it out from there?

Smokn '94 Z

You can have your trans vacuum modulated.... Bryan @ pcm forless was successfull at fixing mine with tuning.