Transmission shifting 1>2>1>2>1>2 @ WOT

[BTLD_LS1]

I took the car out to the track last night and the transmission was acting up the whole night and i have no idea why.

First pass of the night I pulled second gear only to watch the A/F on the wide band to make sure everything looked good, stayed richer than 11.8:1 on the wideband the whole time, so all was good and decided to come around and make a second pass. Put the car in manual first launched, the car immediately shifted to second upon launch, I was going no faster than 10-15 MPH as this point. Came around made a second pass in OD to see what would happen, same result.

I went in to the tune and reset all the tables to stock with the exception of full throttle shift RPM and Full throttle enable %. Made another pass, (as seen in the log) put the car in manual low and the car held first a little longer, still shifted to 2nd on its own earlier than 7000 RPM.

Came around made another pass, this one at frame 2240, with the car again in manual 1st, and the transmission shifted to second early, then back to first, then back to second, then back to first, and then to second and proceeded to stay in second.

Im running a 5K RPM non lock-up converter and a Performabuilt Level II transmission.

Any ideas? i have never experienced anything like this before.

[BTLD_LS1]

the car will do a burn out in first and NOT shift to second on its own, also on the street, if u manually pull it down to first it will hold first til u shift it as well, only appears to happen when launch from a dead stop

[bullygoat]

Well first off, you're not logging any trans data so there's no way to tell for sure exactly what's going on. Secondly, you're over maxing your injectors. 112% is way to high. You should be around 90% max. I'd get that fixed before you ruin the motor and then work on your trans issues.

[Russ K]

http://www.hptuners.com/forum/showthread.php?p=101510

Russ Kemp

[BTLD_LS1]

http://www.hptuners.com/forum/showthread.php?p=101510

Russ Kemp

Thanks Russ, Frost pointed me towards this over on LS1tech and it seemed to fix the issue as the transmission actually shifts normal at part throttle. going to the track tonight to find out if it fixed @ WOT

[98hc4mula]

that was a fix for my problem. I have a 4l80 that was short shifting and giviing the p0121 code. Hope that you found your problem

[BTLD_LS1]

that was a fix for my problem. I have a 4l80 that was short shifting and giviing the p0121 code. Hope that you found your problem

Yep, that was it. For the first time since 06 the car actually shifts like it is supposed to lol