Stalls at idle?

MYHONDAHATESME

MEMBER
2004 HONDA CIVIC
1.7L
4 CYL
4WD
AUTOMATIC
140,000 MILES

The engine isn't flooded, spark plugs have been replaced. I replaced the battery a few months ago, the timing belt is fine. And today I replaced the fuel pump and filter.

After I replaced the fuel pump I tried starting it and I had to press the gas pedal again but when I let it run for a minute, then cut the car off and tried again, the car started right up? I don't know what the issue could be.

To elaborate: I replaced the fuel pump, had to hold the gas to start it, let it run for a while, then cut the car off. Then when I tried again, it started right up.

Help I am out of ideas.

1 Reply

SCGRANTURISMO

MECHANIC
4,897 POSTS

Hello,

This could be a problem with your vehicle's Idle Air Control (IAC) valve. I'm going to tell you something that is totally counterintuitive. When you step on. the gas pedal, you are not really adding gas to the engine. What you are really doing, is opening up the throttle, which allows more air into the engine. As hard as this is to believe, engines are really nothing more than air pumps with a sprinkle of gas added for combustion. In fact an engine running at stoichmetric operation, which is perfect combustion, has an air to fuel ration of 14.7 parts air to 1 part fuel. So, your vehicle's problem could be it's not getting the proper amount of air, and when you step on the gas you are opening the throttle letting air around the throttle plate, which the IAC valve should be doing. I have included a couple of links below for you to go to.

https://www.2carpros.com/articles/engine-cranks-excessively-before-starting
https://www.2carpros.com/articles/how-to-replace-an-idle-speed-control-motor-iac

I have included for you the locations of the IAC valve on your vehicle. Please go through these guides and get back to us with what you are able to find out.

Thanks,
Alex
2CarPros

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