98pontiacfirehawk

To start off Ive had to rebuild the 4L60E transmission in a 1999 TA 2 within a month due to delayed 1-2 shift shifting to high from 1-2. My wifes car so she didnt say nothing until it was to late so, I went through it again totally. After the second rebuild it was doing fine after a week she said it was delayed 1-2 shift again so, I went ahead and bought a new transmission didnt have time to rebuild it again. After I put the new transmission in I drove it to go through a few load cycles and it did it again 1-2 delayed shift replaced the TPS since it pop and it did fine for a few cycles same thing so, I replaced the computer same thing. I check the wiring appeared fined Ohmed it to make sure but, if I leave the TPS unhook it shifts fine with no problems. I have came to the conclussion whatever the issue is it has burned two transmission and I cant find the issue. Wiring, computer, TPS cleaned the MAF and replaced. Wht the hell is the problem? Ive already changed the TPS 3 times to make sure it isnt the problem as well as the MAP sensor. The MAF I swap with was a used one so the condition is really unknown been some time. Whatever it is it is dealing with after a few cycles like it has learned and applied to its tables. Does the Cam and Crank sensor have anything to do with the transmission load? Also, no stall. No big cam basicly stock car. Onlyu thing I havent check is the O'2 which they are pretty much new but that doesnt matter, I know the O'2 and the MAF are on the same circuit so I wounder if they are giving false readings or something.

01ssreda4

iTrader: (96)

A scan with a program like HPTuners when it does the delayed shift would help a lot. Have you considered taking to a trans shop for diagnosis?

98pontiacfirehawk

A trans shop would not be helpful. My scanner was showing it was shifting as being commanded. I found the issue and it is due to an intake leak making the pcm believing the engine was under load. I just happen to seen at idle in park the engine was showing load. What is bad, I keep skipping over engine parameters going directly to tranny parameters. I feel like a dumbass due to wasted time. Can’t believe burned 2 trannies due to an intake leak varying the line pressure.

Moter

iTrader: (20)

Wow....that is the first time i have ever heard of a lean condition to cause a delayed 1-2 shift...and not turn on the mil. Your explination makes no sense.

M56x-11

I have a similar issue with my trans as well. Where did and how did you find the intake leak?
I've been chasing this issue for weeks. I'm running out of options...