surging idle mysterious stall????92 cav

[gunner181]

92 cav 2.2L MPFI
There is a lot here but i'll try to keep it short.
Bought car and it had a high idle. Then after 2 or 3 mo it started stalling. Had a head gasket put in ( it was leaking). This stall had gotten worse and it would only do it at low speeds at certain places. So it was checked by a mechanic and it was determined that it needed a new computer, (same one who did gasket) he could never get it to stall for him. 3 computers were put in (all from "junk yards" and none fixed the problem (idle). He wants to try a new one $$?? He was doing the "tap test" to the computers and the engine would stumble and stall.this is why he want's to try a new one I sorta think there are 2 problems here. I replaced the IAC as well as checked the CTS, TPS, ATS all seem ok. After I put the new IAC in and did a idle relearn this is when it started surging. But before the car would just stay at high idle, now it will come down to normal but go back up.So I drove the car to work and found that the car will accelerate on its own to 40 m/hr. It did stall on me though at a low speed in the morning. but fired back up. When it was originally stalling before new IAC I was getting good spark on all plugs. I put in a new fuel filter. I"VE CHECK EVERYWHERE BUT NO SIGN OF VACUUM LEAKS??. I havn't checked CPS. I unplugged the TCC solenoid and it still stalled. I started to check the MAP I got a 5V ref with key on then when I started it no drop in volts???

I get a MAP Code 33
I had a 42 EST but didn't come back
and a 66 air cond pressure


I need some direction.

Thanks
gunner

[gunner181]

come on, somebody must have some sort of suggestion???

I need to talk to someone who knows the sensor circuit well.

ie *how does the air intake temperature sensor work in regards to engine control). (Does the EGR have vacuum on it at idle). MAP sensor and how it relates to engine performance.

Please help

gunner

[gunner181]

I've been researching on the net and found that a diode leak on the alternator can cause the computer to act up, anyone have any thoughts??? I tried to test for AC voltage out of the alternator terminal but got like 30 VAC ????

Please help... Someone..

Does anyone know of a chat room, I have a lot of questions as you can see..



thanks
gunner

[gunner181]

I'm kinda bummed out noboby has any idea's.

The original post is long and maybe was a bit confusing but I am really eagar to solve the problem!!!

I'll take anything


later

gunner