305 surging after warm at idle
 

Hi guys,
Im new to the forum. I have a 91' camaro RS with the 305 TBI. It starts and runs good but after the car gets warmed up somtimes at a red light when my foot is off the gas the engine will surge. Its like it want to die then the computer recovers and the process repeats. It doesnt happen often and at one idle it will and one it wont on the same drive.
Ive noticed if at a red light I roll up very slowly before stopping it wont surge but if I do a harder stop it will. Like if im giving it time to adjust to the idle it will be fine but if I dont it will surge.
Ive also noticed poor fuel economy and a semi high idle.
Any Ideas? Its my first car so I dont want to throw too much into it. I just want it to run nice. Im going to pop the EGR valve off tommarow to see if it is shot and mabey replace the o2 sensor just incase.
Thanks

Re: 305 surging after warm at idle
 

Did you ever find the problem , my car is doing the same thing.

Re: 305 surging after warm at idle
 

Wild Guess: Dirty IAC passages, dirty throttle body. Perhaps the IAC motor is getting weak?

Connect a scan tool, look at the commanded idle speed vs. the actual idle speed. For that matter, look at all the rest of the data stream.

Re: 305 surging after warm at idle
 

any vacuum leaks ?

Re: 305 surging after warm at idle
 

no vacuum leaks, going to look at the iac this weekend

Re: 305 surging after warm at idle
 

Tired fuel pump (check fuel pressure).
Failing alternator voltage regulator (check if voltage drops at lower rpm).