Has anyone experienced this?

I have an '03 Screw with a 4.6L engine. I seem to be having intermittent trouble with routinely starting the engine and having it idle on it's own.

I went out after work today and went to start the engine and it turned over normally, but would not idle at all. You can hear it fire up and rpms reach the usual level at startup then it just quits. I can keep the engine running with my foot on the gas pedal but as soon as I release it....nothing. I guess the best way to explain it is that it's like releasing the pedal on a gas powered golf cart. I must have started the thing 10 times or so.

Then all of a sudden I turn the key again and PRESTO....idling normally.

Oh yeah, it happened about 3 months ago but not since then (until now)

Any info will be GREATLY appreciated!! Thanks!

 

I too have experienced this same problem. Mine did it everyday for about a month, and then all of the sudden worked properly again. I have been told it's an "Idle Air Control Valve." A mechanic told me it was from lack of maintenance. I ran some of that Chevron techron fuel treatment through the tank 2 times, and I haven't had the issue come up again.

 

I have a question for you, do you always push on the gas pedal when you start your truck?

If you do you need to stop it. Even if you just push on it a tiny bit like resting your foot on it at start up. When you push the pedal during start up it confuses the PCM and really plays havoc on the start up profile.

The only time you should ever need to press on the pedal during start up is when it is -20 degrees outside. Or if the engine is flooded. which the only cause of flooding on a modern engine is from pushing the pedal during start up when it is not needed.

Good luck-

 

Actually, if you consult your owner's manual, it suggests cracking the throttle if you are having trouble with the engine starting. The original poster has been doing the correct thing to compensate for a sticking (closed) IAC valve.

Steve

 

Do you continue driving after the fuel light comes on? I had this happening and one day it did not start at all. It was towed and the fuel pump replaced. That was at 13k miles.

 

Thanks for the replies! I think I'll talk to my dealer about this...

 

One time when I was mad at my 5.4 I unplugged the MAF sensor and drove it. Ran fine for about 12 miles then the next time I started it it did pretty much what you describe. Of course it resulted in a CEL. That kind of made me happy agian since I was mad my motor wouldn't run right and the CEL never came on.

I would still suspect the IAC because it is usually the problem with any idle isssues. That and that pvc elbow located just behind it.

Some times just cleaning that MAF works wonders too.

tom

 

I have the same probelm right now. Did you find out yet what went wrong with yours? Where is the Idle air contol sensor? I was thinking of replacing that first.
I have a 97 F150 Xl 4.6 2WD Supercab

 

The IAC is a canister shaped doo-hickey that is behind the throttle body.

There are two black hard rubber hoses that come into the intake. One of them goes to the driver side cylinder cover. The other goes behind the engine. Follow it, and you will find it. (It's not the black thing that the hose goes through, its after that).

Sorry for my use of big, hard to grasp words here

 

My '99 5.4 has been doing this for 2-3 months. If it doesn't start right off the bat, I baby it down the road and at some point it catches and is fine. May go for 3-4 days without occurring. I haven't seen a post that the problem has been corrected but I assume silence means it has.

Is the idle air control valve a dealer only part? The NAPA and Autozone web sites do not list it. Thanks