I have a 98 GTP with light mods including a dhp pcm. The problem only occurs once the car is fully warmed up and its happens off and on.

Starting out in drive from a dead stop then accelerating, takes off fine in first gear then it will shift into 2nd and then lock up the convertor as soon as it it shifts and stay locked for 1-2 sec then unlock and shift into 3rd normal and then 4th. It also seems that it shifts into all the gears very early if Im light on the peddel. It also does the whole lock, unlock in 2nd under any throttle position....even WOT.
I also noted on occasion that after downshifting to allmost a complete stop in will lock up as well then unlock. Real hard to explain this.

It will only do it once warmed up
It does not do it all the time
Its been doing this since Ive bought the car 6months ago with all the mods listed.
The car has 98,000 miles on it, no codes, fluid is red, clean and does not smell burnt.

Could this be a problem with a issue the DHP PCM? I read strange trans issues with DHP pcms.

This is my only Mode of transportation, I have 2 little girls and no money. Im hoping its someting easy to fix untill I can save up for a used, rebuilt trans from Dave. Thanks for reading guys.

Jason

DHP pcms have always been in my eyes one of the better ones to get and I have never ran into any problems using them. Your problem sounds like a TCC solenoid or valve body problem but without looking at it then its really hard to say. It could be as simple as a wiring problem or a bad speed sensor in the trans causing this also. Without having a scan tool to watch what is going on exactly when it happens there really no quick easy fix-answer to your problem. Do you have a scan tool or know someone who does? I dont mean a simple code reader, you need to be able to watch data for the transmission to verify everything is working ok and no codes pop up at the instant the problem occurs. An easy thing to try out would be to swap in a stock pcm for a few days to see if it has any effect on it and that way you rule out the pcm.

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I have one of those $200 autozone dataloggers but it has no trans functions. I'll make a post in the appropiate section and see if I can get some help logging the info and borrow a PCM.

Thanks,
Jason