Hello, I'm new to this board. I've got an '86 Fbird with 2.8/700r4. It has had a cold start problem for quiet some time. It will not idle when cold and RPM fluctuates while in park if it does idle. After warm up, all is well. Checked for codes, none showed up. I replaced the IAC to no avail. What else should I be looking for/at?

Thanks,
Keith

 

check your egr system, and welcome to the boards

 

My '87 camaro had the same problem. Hard to start and then fluctuates until warm. I had a bad Intake temp. sensor (no code showing). It was telling the ecm that the air coming in was 180 degrees. Check the resistance of the sensor. Should be around 3500 ohms when cold (70 degrees) and gets lower as it gets hotter, mine was 300 at 70* which would actually be 180* if it was accurate.
I also replaced the coolant temp sensor in the intake manifold underneath the throttle body, just in case that was bad or misreading.
I also had a vacuum leak at the pcv valve.
Now it runs great. It was 29* this morning and it started right up and the idle was smooth.

 

Thanks fellas, I'll give those a try and see how she does. It's been like this for several years. It's also a second car and is not driven everyday.

Thanks again,
Keith

 

I am having a similar problem but with a 305 TPI what will the EGR system have to do with it. The only reason I am asking is because i dont want to take off my TPI unless I have to, its not fun.

 

The EGR can get stuck open. Acts the same as a vacuum leak at idle.
Some other posts have said that cleaning the throttle body and IAC has cured this problem.

 

Is there a way to pinpoint the EGR problem or is it trial and error, (money pit?)

 

That's my problem, too.
I haven't changed the Intake sensor yet.
I will shortly.
Also suggested is to replace the IAC, same time?
Will the running poorly engine at start up, will it destroy a Catalytic converter? My converter is now hallow due to the innards fell apart and flowed to my muffler, causing blockage. Discovered when I replaced the muffler other day.