cold stall and idle hunting
Asked by devilishdave Oct 13, 2008 at 12:56 PM about the 1985 Chevrolet Corvette
Question type: Maintenance & Repair
i have a cold stall or hunting idle problem on a 1985 corvette (only cold)runs great when hot all the injectors have been replaced 8 months ago
any ideas?
8 Answers
For the idle hunting problem try the Throttle Positioning Sensor.
i really dont agree tps only tell computer where the throttle is the iac controls iddle cleaning the iac normally cures problem it still works if its searching for iddle
had the same problem on my 94.. replaced the egr and problem solved. If the egr was the culprit then u will most likely have to change the oxy sensors too. your problem was identical to mine. everything ran great till it warmed up.
Given this occurs in COLD weather, I would have to agree with the gentleman that mentioned the Idle/Air Control (IAC) Valve. It would produce your symptoms, although I do not recommend cleaning it, nor does the manufacturer. I am fairly certain replacing the IAC would solve your problem. EGR would not effect the engine until it warms up, and the TPS sensor only relays the position of the throttle and would not cause idle hunting. Keep in mind though, depending on which TPI setup you have, it may be equipped with a cold start injector and it would produce similar symptoms if that injector is bad.
Steve7seven answered 14 years ago
I own a 94 and it only hunts when its warm. We changed the ecm, checked for vacumn leaks, bypassed the egr to see if anything can stop the problem. We made sure the IAC was clean and working porperly. Something is telling it to surge to 150 after it heats up. The shop has been working on this for over three weeks. We are now checking to see if the o2 sensors are bad even tho they are reading that they are fine. Any feedback??
Steve7seven answered 14 years ago
I own a 94 and it only hunts when its warm. We changed the ecm, checked for vacumn leaks, bypassed the egr to see if anything can stop the problem. We made sure the IAC was clean and working porperly. Something is telling it to surge to 150 after it heats up. The shop has been working on this for over three weeks. We are now checking to see if the o2 sensors are bad even tho they are reading that they are fine. Any feedback??