LS1 4l60E Funky 2-3 shift at WOT.

[Derek]

Well, I just cannot figure this out, I'm hoping its not the tranny but who knows! Last fall just before going in storage my car went to the track and ran like a dream. Now, when I got it out this spring the car will not shift from 2-3 at WOT. It runs like a dream and shifts perfectly normal everywhere else, its just from 2-3 at WOT it will not shift, instead it bounces like crazy off the rev limiter until I let up on the gas, then it shifts fine. It never turned any lights on, but we hooked up our scanner to it and I had 2 codes in the history: P0123B Throttle Position Sensor Circuit Volts High, and P1121C throttle position sensor circuit intermittent High Voltage. I installed a ported and bumpstop modded throttle body that I purchased and it had a new TPS sensor on it, I have also descreened my MAF over the winter, otherwise, nothing was messed with. I first thought maybe the blade was opening over 100 percent and throwing the TPS off, but I taped the bumpstop to factory width and it still had the issue. I have also tried a new sensor and that didn't help either. I'm sort of at a loss here for what to try next, could a wiring issue to the TPS cause this? I checked quickly and the wires are all covered yet, so unless they are damaged underneath I can't see an issue. I guess my last resort will be to put a stock throttle body on, from there maybe it actually is a tranny issue? Does anyone have any ideas of what it could possibly be? Any input would be appreciated.

[my95z28]

I know it sounds stupid, but did you check the fluid level in the trans?

[Derek]

I know it sounds stupid, but did you check the fluid level in the trans?

yes, and its perfect and it looks very good and doesn't smell burnt or anything. I forgot to mention that, lol it was one of the first things I checked! Thanks for your input, anyone else? I'd really like to get this squared away so I can get to the track after the GVSU car show!

[Schuby87]

If the only thing that you changed is the new TB, have you tried putting the old TB back on to see if the problem goes away?

[DETROITMUSCLE]

I think he modded his original one, if not I might try a stock MAF as well those always seem to have problem after you descreen them.

[Derek]

I think he modded his original one, if not I might try a stock MAF as well those always seem to have problem after you descreen them.

I'm starting to think I might have to, I can't put the stock TB back on, it was sent in as a core when I purchased this one . I really dont know how it could be the MAF, but crazier things have happened. I guess I'll just have to find a stock TB.

[nascarnate326]

Take it to Hanson and Dykes out in Allendale.

[kammi10]

Take it to Hanson and Dykes out in Allendale.

HAHAHAHAHAH lulz

[Derek]

Take it to Hanson and Dykes out in Allendale.

I certainly hope you are joking here. Considering my family owns the shop.. lol how do you think I've been able to scan for codes, troubleshoot and swap sensors etc... lol I am gonna try and buy a stock screened MAF and try that first, if that doesn't work I'm going to try a stock TB as well.

[Formula Z]

hate to say it derek but thats how all my trans issues started, but i noticed mine doing it going down the dragstrip at wot. id have to let up only for a split second and it would shift and back to the floor, lol. hopefully its not the trans, but sounds like it to me

[JoeliusZ28]

I certainly hope you are joking here. Considering my family owns the shop.. lol how do you think I've been able to scan for codes, troubleshoot and swap sensors etc... lol I am gonna try and buy a stock screened MAF and try that first, if that doesn't work I'm going to try a stock TB as well.

he was definitely joking, he knows that

[Superman09]

I remember my Trans Am did this a couple of times before I put the built trans in. I remember it only happened when I had the shifter selected in either 3 or OD, i forgot which, and whenever it was in the other it made the 2-3 shift just fine? Maybe just a coincidence but have you been throwing it in something different than what you were last year?

[Derek]

I remember my Trans Am did this a couple of times before I put the built trans in. I remember it only happened when I had the shifter selected in either 3 or OD, i forgot which, and whenever it was in the other it made the 2-3 shift just fine? Maybe just a coincidence but have you been throwing it in something different than what you were last year?

nah, its always in drive. I've just assumed it was something sensor related because of the codes that I had pop up. I would think a tranny related code would come up on the scanner if the tranny was failing.. but who knows! I'm going to keep trying different things and getting the tranny checked will be the last resort.

[Superman09]

nah, its always in drive. I've just assumed it was something sensor related because of the codes that I had pop up. I would think a tranny related code would come up on the scanner if the tranny was failing.. but who knows! I'm going to keep trying different things and getting the tranny checked will be the last resort.

yea good thing there is a nice quality service shop pretty close to you!

[SSTODD]

I believe my SLP maf was doing this to me, and I put my stock maf back on and it never happened again.