erratic idle when engine is at operating temp

[93GASE3300]

Whenever I have run my car for a while and it is at operating temp and im at an idle in park my engine will fluctuate in rpms almost to the point where it stalls. Just wondering if someone else has had this problem. If so please tell me how you fixed it.

Thanx

[graden]

might be a bad e.c.m or mabey something small like a mass air sensor or t.p.s sensor

[93GASE3300]

Ill try the tps and mass airflow first. I doubt it is the ecm but I cant rule it out at this point. Thanks for the help

[Back In 92]

Let me know what you find out, my 92 is doing the same thing but all the time and ive already replaced the IAC so i dont know what else it could be.

[93GASE3300]

does anyone know where I can get a service manual or does anyone know the idle learn procedure. I cleaned my throttle body and my car idles high for about five seconds then kicks down. I work on cadillacs and that happens to the cars in the early 90's and the fix is to do a minimum air procedure and a idle learn procedure. I also need the spec for the spec for the voltage that the tps is supposed to read at idle. please let me know if anyone knows.

[hotwilzz]

I have this exact problem with my 92 3.3L I have replaced the ECM, tps. plugs wires etc. Cannot find the problem . I f any one has fixed this pllease chime in

David

[93GASE3300]

Do you have any codes? I have a 27

[hotwilzz]

The only code I have gotten is for the oxygen sensor. But that is erratic as well as I don't drive this car very often, I think it is a gremlin. It still strikes me that the surging idle seems to be at temp. and only in park or neutral. It levels out in drive and doesn'r surge the idle at all.

[Old Guy]

Just a thought, but I would try cleaning your MAF. I've played around with the MAF for quite a while and it'll make your car do wierd things. Probably the most sensitive sensor under the hood.

If that's not it I would look at the TPS. I would have to say it's more likely to be a sensor problem than a ECM problem.

Look at these two pages:

Mass Air Sensor (http://www.cybrrpartspro.com/Chilton%20Manuals/9106m/9106CH04_21.HTML)

Throttle Position Sensor (http://www.cybrrpartspro.com/Chilton%20Manuals/9106m/9106CH04_23.HTML)

Hope this helps you out!!;)

[hotwilzz]

Thanks Tom, I will ck. the Maf. It already has new tps and ecm.


Thanks
David

[9tre Grand amGT]

hey yall my car kinda has tha same problem. when im driving off it starts to hesitate i give it a lil gas and it goes away but then after a lil while it comes back again. it starts to hesitate. so i floor it cuz i get mad and it finally goes away. is that kinda tha same thing.

[scott9050]

the 3.3 is sensitive to slightly plugged fuel filters as well. My olds wagon would buck like a horse until I changed it, and I am getting the same thing with my 3.3 Skylark. Time to change the fuel filter again.

[9tre Grand amGT]

thanks man ill try that. hopefully thats tha problem. tell me if it works out ok.

[schultzie93GT]

the eratic idle has happend on my 93 and all i can tell is that when you shift int park the car is reading it as being between park and nutreal. i havent talked to a mechanic about it but all i do is when it starts to do that i just hit the councel next to the shifterand it stops. i have also noticed that when it does it the light for the indicator wor what gear your in is not fully on in the lil park circle then it comes on after i hit the council right next to the shifter.

[mike_46350]

I'm having the same problem with my 92' grand am se, it only does it when im not on the gas or in park and it even kills the car first time it did it i thought the engine was just cold ...so have any of you figured out how to fix this? thursday or so im changing the fuel pump and oil and oil filter along with some other stuff.

[cage47]

Just a chime in. I have the same problem on my 90 GA LE. Thing is last night I drove to work. Terrible. I just replaced the intake manifold and the egr valve. Had no power and jerked at low rpms. So I unplugged the vacuum line to the pcv valve (no that wasn't it, that's new) but the increased air in the line helped it rev up. Got power. Even starting has been hard but with the line disconnected and getting more air it started right up no hessitation. I'm going to check my fuel pressure regulator and the iac. Then also maybe the tps. Don't know if my tech 4 has an MAF. If it does I don't know where it is.

[BlueBomber]

The problem is the park neutral switch, i have the same problem especially off a cold start up, make sure the indicator light is illuminated on the shifter pannel if not just tap it untill it comes on, it should start and idle fine but the switch will probably turn off again so you will have to tap it again, I am used to mine by now but I should fix it.