Please please help,
I own a 1991 camaro fitted with the 5.0 tpi engine. The car runs very well apart from one problem.

Starting the car from hot and cold is fine.
The car idles very well while the car is in park (automatic).After driving for a while,
when the car comes to a stop at at a say a junction
The tickover starts to drop(while in drive) , this becomes progressively worse (idling also becomes rough) as the temperature builds up and the car has been running for a while , eventually sometimes stalling. But even when the car is hot if the car is pulled to a stop and the auto set in park , the car will not stall , although it does idle quite rough. There is also no fault codes present with this problem

please help chris

 

I am having a similar problem and my car is also a 91 Z with the 305 tpi with a 6spd. It will run fine when cold, but when it get's to operating temp. it will stall when I press the clutch to come to a stop. It acts like it's loading up. Please help Thanks

------------------
91 Z28, 6spd, 4.10 best 1/8th 8.48
90 Bandit 2 #18 stock
93 Typhoon # 804 best 1/8th 6.98
00 SS stock
93 LX 5.0 SC 30k miles
94 GT 7k miles

 

Might be the iac--my 89 350 tpi did the same thing--I reset the iac--but it was a few years ago, so I don't remember the exact procedure to do it.

 

It could be a lot of things, I'c check the IAC first, it's the most likely culprit. I had this problem with my 91 Z28, 305 TPI and I lived with it for a year. I checked EVERYTHING and even hooked it up to a scanner a few times. Nothing. Finally I took it to a really good shop where the mechanic told me that there was a PROM update for all 91 305 (both tpi and tbi) with these symptoms. I was skeptical but a friend who is a mechanic at a dealership said this was a common problem with GM cars. I replaced the PROM and much to my surprise the problem was fixed. I would suggest you check everything you can before you assume it's the PROM though since there's no way to test it. I made several posts on this board over the year that my car had the problem and not one person suggested I needed the updated PROM. I assume that it's not really common knowledge.

------------------
91 Z28
Come see The Vicious...

 

i used to have a 91 z 5 spd with same problem. a thorough throttle body cleaning did the trick

 

SpeedFreek - What do you do for a living bro?
Must be nice to have 6 toys in your driveway!!!

------------------
89 RS V8,Borg-Warner 9-Bolt rear,Open element,Flowmaster.

 

Same car, same tranny (6 speed for now, Im going back) same problem. but mine would have an Idle that would sway up and down. Im changing to LT1 intake, MSD distributer, LT1 injectors and new IAC,Knock and TPS sensors. I will let you know how it comes out.

------------------
91 Z28 5.7l Camaro
T-56,McLeod Street Clutch, Cross Drilled Brakes, KYB's,AFPR, 3.73 Gears, Borla Adjustable Cat Back, Hypertech Chip, Hooker Headers.
more to come....
My 91 Z28

 

do you think it could be my speed sensor making my car stall when coming to a stop and having a rough idle in drive or reverse? i replaced the map,and the iac already next up is a very thourough tb cleaning and what is the PROM how do i replace it and whats the average cost to do it>?