LS1Transam99

iTrader: (6)

When I made my first pass at the track after having my transmission rebuilt, I cut a 1.75 60' and it took off great, but it wouldn't shift into 2nd until I lifted. Datamaster stoped reading mph and the window lit up with a DTC from the transmission. The DTC's I get are:

22-TPS Sensor Low
72-Output Speed Loss

I reset the computer and it ran fine on the next pass.

That was 3 months ago and today I'm in Maryland for the Super Chevy Show doing test and tune. I decided to spray a 50 shot off the line to see if I could lift the wheels (which I did!) and it left hard, cutting a 1.649 60' and wouldn't shift into second, the datamaster started beeping again with the same DTC. I reset the computer and its running great again.

Why would my speed sensor crap out on a hard launch? What can I do to prevent this? Could anything have gone wrong durin the rebuild that would cause this?

infinitebird

iTrader: (11)

sounds like the obd1 high stall problem. apparantly ed wright, pcmforless, etc. can fix it. I've heard conflicting reports on that though.

A popular fix is to convert to obd2.

Ed Wright

iTrader: (1)

I have yet to run onto one I couldn't make shift, at least everybody I have heard back from have no shift problems. Some cars don't loose their speed sensor signal, but still won't shift, so that isn't the cause. My '96 TA was like that. An OBD2 PCM will fix that, but in most applications don't make quite as much power.

LS1Transam99

iTrader: (6)

Why does it happen so rarely? or have I just been lucky?

What exactly causes it?

Thanks for the help

slowmofo

iTrader: (6)

happenes to me all the time if I launch hard and hook. anything in the 1.86 or lower 60 it happens to me.

TwoFast4Lv

iTrader: (8)

Guys let me tell you a story many know. We fought this issue for years. We spent Thousands on it to the point a friend and I pioneered the OBD-II swap.

Not everyone wanted to swap so we kept testing.

Ed here took it upon himself to put a huge stall in his car and start testing the code one piece at a time. He is the Master and can work in areas of the code no one would help us with.

One day Ed shoots me a file and Says "try this" We stuffed it in a 10 second N2O car and right out of the gate it cut a 1.3 60ft and ran a solid ten second pass! We were aprehensive I will admit. banging you $10k motor off the limiter on juice scares the hell out of you that is for sure!

Alot of people were pissed off at me because I made a deal with Ed to NOT share the code and to this day I have pointed people back to him every time it comes up.

What can I says I am a man of my word and he did what no one else could or WOULD at the time. ANY tune that works for this is a copy of his code. I would rather he getts the money for what he engineered

Ed can fix your car, ask him what it will take


BTW 1.52 60fts tires up Launches last week on Dr radials!

carzman5678

Yeah, im fixind to get my "stall wall" removed from my car by PCMforless. It comes on when I cut a 1.7 60'. That with just a stall and 3.23 gears on DR's with stock suspension.

LS1Transam99

iTrader: (6)

I e-mailed Jeff Creech at Carolina Auto Masters since I already have free updates from him. He said he had a fix for this as well and he'll have it e-mailed to me by tuesday hopefully

Incidently, I had a 1.68 60' today without the nitrous and the car shifted fine. I guess launching of somethin as small as a 50 shot is enough to freak the PCM out.

buffman

iTrader: (9)

I had issues with BHs high stall fix (figured i'd be unlucky and have the OBd1 high stall issues) quick shifting out of 1st gear for no reason, so I had him remove the High stall fix, and I haven't had a problem yet. Although my best 60ft so far is only a 1.84