Car stalls at idle - no problems in computer

stalls

#1

All of the sudden, my car began stalling whenever it idles: stopped at a light or parked. It starts and drives just fine. But given a minute or less at idle, it will always stall. No weird noises or jolts. It had never done this before yesterday.

I thought bad gas, so I put in some fuel injection cleaner. That didn’t help.

I took it to the mechanic. The computer shows that all systems are working fine. He replaced the MAP sensor, which did not help. He took off the fuel filter, which he said was full of “junk”. He is replacing the fuel line and fuel filter tomorrow, but he doesn’t seem to think this will fix the problem. He is essentially clueless about how to proceed if the filter/fuel line change doesn’t do the trick.

Other info: I had just filled up the a full tank of gas the day before this happened. Also, two weeks before, I had a new battery put in.

What could be causing this problem to begin all of the sudden? PLEASE HELP!


#2

Year, make, and model please? We need more info.

A dirty fuel filter may have something to do with the problem.

I’d also want the mechanic to check the Idle Air Control (IAC) valve. This is what controls the idle speed, based on a signal from the computer. If the IAC valve is dirty or not working correctly you can get an incorrect idle speed or no idle at all.


#3

It is a 98 Camry 4-cylander. 120,000 miles.


#4

For the I4 Camary engine, have the throttle body cleaned with emphasis on the Idle Air Control passage. The IAC can get sticky and cannot respond to the computer’s speed adjustment commands. If cleaning the IAC passage and pintle does not correct the problem, the IAC will have to be replaced. The part is rather pricy and so far it doesn’t appear to be available aftermarket.

One way to check to see if the IAC is responding is to watch the tachometer as you shift from park to neutral. If the needle bumps up and settles back, the IAC is responding appropiately and the problem is probably elsewhere.

Hope that helps.


#5

Update: Mechanic said that the IAC valve was one of the first things that he thought about, but that my car “doesn’t have one.” Is this possible? He said that my car has a MAP sensor instead, and that they already tried replacing that, which didn’t work.


#6

Update: Mechanic said that the IAC valve was one of the first things that he thought about, but that my car “doesn’t have one.” Is this possible? He said that my car has a MAP sensor instead, and that they already tried replacing that, which didn’t work.


#7

You need to find a mechanic who knows what he’s doing. Your cars engine does indeed have an Idle Air Control motor.

http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c1528009269b

Tester


#8

Your car has both a MAP sensor and an IAC. The two are not related, so having one does not eliminate the need for the other. You do indeed have a crazy mechanic. You need to run, not walk to find another mechanic. There is no need for a real mechanic to guess about this problem. There are specific troubleshooting procedures to follow. As was said by others, those procedures will almost certainly lead to the IAC being at fault.


#9

Download and print these instructions of the idle air control valve (IAC) for your mechanic : http://www.autozone.com/N,15701286/shopping/partTypeResultSet.htm Ask your mechanic to get the a spray can of throttle body cleaner and use it in the IAC air passages. Spray the cleaner into every port and down the throttle bore. Spray liberally two, or more, times. Let it soak. Spray again. Run engine and check idle performance.


#10

Yes the I4 does have a IAC it is on the bottom side of the throttle body and really hard to see. It is has small coolant hoses going to it and an oval socket for the wiring plug. This has caused problems for me but cleaning through the square port just in front of and below the throttle plate clears the problems. My problem shows up as unusually low idle and stalling on a cold start.