Howdy all, got a question for you thats driving me insane, and the person who tuned my car has NOT been helpful at all. He's a well known programmer that the community recomends and trusts, thats all I'll say for now, however he's been very unhelpful as since the flash my PCM with a 94 F-body based tune. I have lost engine braking in OD and TCC lock-up in D/OD.

When I drove there, I had engine breaking in OD, and TCC lock-up. When I left, I didn't. I went back, but he has refused to help me, i've already put a stop payment and am disputed the charge with my credit card. But i'm still out of luck.

Some specs.

The car is a 1989 TransAm GTA with a LT1/4L60 swap out of a 1994 Buick Road Master.

The engine was converted to run 1 knock sensor like a F-body vs the 2 that a B-body has. The harness does not have the wires anymore for a 2nd knock sensor. i'm considering pinning it into the harness and running two knock sensors like a B-body.

The reason I got a tune is because I figured with the different cam/heads that I wouldn't get the best performance out of a 94 A4 f-body tune. Also, because of the lack of a 2nd knock sensor the PCM threw a code and refused to enter closed loop. Hence why I got it tuned with a F-body based tune.

Since the flash I lost OD engine braking in all gears, and TCC will no longer engage.

I pulled the codes using TTS datamaster (I have a cable) and saw that I had code 83 which from everything I have searched for ends up being related to the TCC PWM solenoid on 95's and up.

Using Tunercat I checked the VIN and it shows that the base tune used to flash this PCM was built from a 94 Pontiac tune.

After reading for a good long while (and driving the car around in 3rd gear without TC lock-up) I decided to get the cables/software to tune it myself since this well known tuner did NOT want to help me and denied that his tune did anything to the car. And I want to start tuning it myself.

I downloaded the tune from the PCM and disabled code 83 in the tune, then reflashed it with the modifed bin. Now I have OD back, still don't have TCC and engine braking though. If I let off the gas, RPM's fall to zero like I put it in neutral. If I give it gas the engine revs up to where the rev's should be in 3rd, then with slightly more throttle the trans grabs again and upshifts to OD then its crusing as normal minus TC lockup.

If I put the shifter in D, I get engine braking in all gears back, though torque converter lock-up is still missing. I have yet to see the PCM command it yet.

Can anyone assist me with this? I can't find a virgin 94 A4 f-body tune, and don't trust the ones I found on http://www.bfranker.badz28.com/LT1Edit/LT1files.htm. There are only a few 94 tunes listed there for F-body A4s.

I can provide datalogs as requested. Here's one today, that I just did after flashing the PCM. It was just a quick jaunt on the highway and back again. Maybe later tonight when traffic dies down i'll go for a longer data log.

http://home.comcast.net/~thirdgen89g...ogs/code83.uni

 

Post the 'tune' thats currently on the car. I wanna take a look at it.

 

If the wrong type of file (EE vs EEB) is loaded, you will lose torque converter lockup. When I started playing with tuning LT1's in the late 90's, I figured this out on my own, swapping things around in my PCM. Make sure that the correct flash was put in the PCM; good chance it was not.

 

Assume you meant KT1/4L60E not 4L60 in the OP. You should verify if TCC PWM solenoid is present or not. ..as I am not familiar with the buick transmission setups. For the F-Body the '94 4l60E transmission does not have a TCC PWM solenoid. It is important to match the correct transmission, harness and PCM code for the '94 or '95 years. Or you will get a DTC 83. If the tranny has a TCC PWM solenoid you need '95 PCM code and harness, if tranny does not have PWM then you need '94 code. Since this is only an A4 problem (the code for '94 and '95 M6 is interchangeable) mixing '94 and '95 PCM code is easy to do. ...E-mailed you a known good (off my car, prior to mods) stock '94 A4 tune in case you need it.

 

The wire for TCC PWM isn't present in the harness, and it is a 94 4L60E. Already traced that wire down when I got code 83, its not there. I've dropped the pan and there are only the 2 solenoids that would be in a 94, not the 3 like a PWM trans.

As far as the tune, i can post it. In the tune that was on the car, code 83 was checked in the switches, I disabled it, and it helped some, but still can't go into OD and cruise because the slightest lift off the throttle and it will disengage. Lift completely off the idle at any speed in OD and the RPM will drop to idle.

Pop it in 3rd, and engine braking comes back immeadiately. In the tune below, the switch for code 83 is checked, I disabled it, but it didn't make a difference really. I could get it into 4th but it would not stay there unless under constant acceleration.
http://home.comcast.net/~thirdgen89g...ginal_tune.bin

 

TCC change has nothing to do with $EE vs $EEb, just 94 vs 95+.


I've had a 95 bin in my 94 for years now.

 

I would start by putting a virgin 94 or 95 bin in there.

The only things I did to the 95 bin on mine were to disable the DTC and change all the TCC DC values to 100%. No idea if the latter was needed, but it seemed like a good CYA...