95 Buick Riv with 4T65E and Series II

[djmadalena]

Hi all I'm new to this so here is my problem I have a 1995 Buick Riveria and I decided to put a Series II L67 engine in my car I have it installed along with a 4T65E trans non-HD and I have wired in a PCM out of a 1998 Buick Riveria I have the car runing with some issues on is my trans shifts kinda funny it shifts late and hard especially when I get on it and the PCM sets an incorrect gear ratio code. also my IPC wont show the temp and it is supposed to get its info via uart. and my trac off light stays on all the time if anyone can help with any of these issues it would be greatly appreciated. my main concern at this time is the trans shifting. I am currently unemployed and it was the only trans I could afford. I plan on changeing it later when I have some funds.
Thanks again

[Trannyman95]

If you are using a pcm for a supercharged engine than that is your problem with the incorrect gear ratio code. The supercharged cars have a 2.93 overall trans ratio and the non supercharged 3800 cars mainly got 3.29 gears, while some had 3.05 gearing. If you have the trans code I could verify your gear ratio or if you know what car it came from that would probably tell me what gears it should have. You need to tune the gear ratio for the car in the transmission tables. This trans, if from a 3800 car, should have a diff ratio of 3.29. The gear ratios are changed in with different drive and driven sprockets that the chain ride on. The 3.29 ratio trans has a 35 drive and 35 driven sprocket, effectively a 1:1 ratio. The supercharged trans had a 37 drive and 33 driven, which over-drives the trans giving you a 2.93 ratio and this is where your problem is and the pcm needs to be tuned to accomodate this. I hope this helps, good luck with it!