Purchased a 96 camry, and I just noticed an intermintent idle failure. does it at hot starts not happened at cold start but would not rule it out. only drove it 100 miles and started it 15 times. 5 of those starts i got no idle. two of which I had to put my foot on the brake and gas to get moving again after reving engine a couple of times and still cut out. Once going no stops at lights everything ran fine until ignition cut off and restart.

3 of the no idle starts i hit the gas at ignition to 4000 rpm and then held idle at 750 no problems until i cut the engine off. the last of these three pedal pushes to keep engine running i heard some kind of relay or something click in engine compartment like a fan switch then idle held at 750.

anyone?

thanks,

Pete

 

Does the engine start up the same when hot or cold, just does not idle when hot?

Does the engine run OK when hot, has power, no miss, etc, just does not idle?

What happens to the idle when the AC system is turned on?

When the click was heard was the AC compressor or the radiator coolant fans turning on?

 

1) Not sure if it never doesn't start cold. It started fine cold this morning. i tried it 5 times and it held idle at cold start up each time. So I took the camry around the block and let engine temp get up to 190. It started 4 times with holding idle at 750 then the 5th time no idle. I then punched the gas with ignition key on start with starter cranking. with ignition engine ran at 4000 rpm then held idle. Now at this hot temp the only way it starts is by using gas pedal with ignition on.

2) engine runs fine when hot. Just won't start up and idle without the gas pedal and high rpm to return to idle. And sometimes it won't idle even after i do this: hit the gas at ignition. When this happens, to get the car to go, i need to hit gas and brake while i put trans in drive. then everything runs fine untill next hot start up.

3) I think the click was the AC compressor.

 

Might check the Intake Air Control (IAC) valve. This valve is located on the throttle body. It controls bypass air around the throttle plate to control idle RPM. It adjusts engine idle in response to conditions such as the AC compressor working and for idle-up speed when engine is cold.

When the AC compressor is on a signal is sent to the computer. The computer opens the valve more to increase RPM. For cold states the computer uses a coolant temp sensor to know when the coolant is hot or cold.

The valve appears to be working when AC compressor is on and at cold start.

The internet is full of posts on how to clean the IAC valve.

Might also check the engine coolant sensor (ECT) for the computer. A bad sensor can cause problems, typically though poor engine performance when hot.

Also the some component of the EGR system may be allowing the EGR valve to be open at times when the engine is hot. This would cause a very rough idle or the engine to stall at idle.

Guessing though if the engine idles OK when the AC compressor is working this place to start is the IAC valve.

The Autozone website has very good info in the sites vehicle repair section, you need to register but this is free.

 

Thanks for the replys,

What do you think about there being an issue with the TPS?

the car is not starting now even though its almost entirely cooled down and using gas pedal too.

You are saying that maybe my egr valve could be open now. How do i test to see if its open? I think its vacuum actuated.

 

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