No start after replacing IAC valve

IJISTNEEDSOMEHELPLOL

MEMBER
2003 CHEVROLET MALIBU
6 CYL
2WD
AUTOMATIC
200,000 MILES

Fiancé's car has had a rough idle for quite some time, but here recently it has gotten worse, it has gotten to the point where if she has stopped for too long it will stall out and shut off. So, I thought it was the IAC valve and I replaced the valve after replacing the car will crank but will not turn over. So, I put the old IAC valve back on the car and still no start, but it will crank like no tomorrow. Also, it does have a fairly new alternator, a brand new, starter a brand new, battery brand new serpentine belt, and tensioner pulley. I did check fuel pressure and it is getting at accurate fuel to the fuel rails and I did replace the spark plugs and wires about a year ago. It does have a check engine light on and I'm working on getting the codes but the light has been on before this problem arose.

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,867 POSTS

Hi,

If it's new, the PCM needs to reprogram the IAC. Turn the ignition key to the run position (not start) and count to three. Turn the key off. See if it starts then.

Also, make sure nothing was left disconnected as far as electrical or vacuum-related components. If everything looks connected and the aforementioned procedure doesn't help, move to the next step.

If you have fuel pressure, either you lost the ignition spark or the injector pulse. Do me a favor. See if it starts for a couple of seconds using starting fluid and then stalls. If it does, then we know it's a fuel-related issue. If it doesn't start, I need you to check for spark to the plugs.

Here is a link that explains how to test for spark:

https://www.2carpros.com/articles/how-to-test-an-ignition-system

Also, here is a link that explains the most common causes of a crank no start condition.

https://www.2carpros.com/articles/car-cranks-but-wont-start

Let me know what you find. Also, I attached the directions for the removal and replacement of the IAC for you below. I realize it is a straightforward job but look at them to see if anything was missed.

Take care,

Joe

See pics below.

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