2.8 MPFI 1988 v6 firebird.

IAT - ok
MAF - ok
CTS - ok
TPS - ok
O2 - ok

At idle car stays at 3000 rpms! Car also climbs in MPH with car in gear! i.e. at 35mph in 3rd gear, I wasn't even touching the gas and it climbed up to 45!

This is very bad on the 1 --> 2 shift in the rain, basically a 4000 dump. :/

Help!

I checked all the aforementioned sensors with a scantool and they are ok. Just put in a new t5, but the car has done this for months before hand. No visible vacuum leaks.

Owner claims he has taken intake manifold off "five or six times" without replacing gasket.

 

changing that gasket might be a good place to start.

 

You think that could be it? I do say that it would create a major vacuum leak if he doesn't have any gasket material left

 

i dunno that much about v6's... is it a tbi? check your butterfly's, they may ahve come out of round... my honda's(yes yes, dont blast me for that, its my everyday driver, my 74 Z28 is my weekend cruiser) butterflys came out of round somehow, and it continually wants to idle up really high

 

nah, it's MPFI. I am going to replace the throttle body and IAC with those from my 86 fbird parts car and change the gaskets. We shall see if that fixes the problem.