Hi all, Having a problem with my 1999 f150 triton 5.4 w/ 52,000 miles, stalling at start up. After a couple of minutes of nursing it along it runs OK again. Any ideas? Truck had 30,000 mile full service at the ford dealer. Thank for your help.

 

You need to clean the IAC on the back of the intake.

 

Thanks T, What brand of cleaner is safe to clean The IAC and the throttle body. I have read that the throttle body has a special coating that could be damaged if you use the wrong stuff. Thanks.

 

Could also be an air leak on your intake.

I had a stalling problem and it turned out to be some loose connections on my K&N FIPK, creating an air leak.

Tightening it all up cured the problem in my case...

 

I have not pulled the throttle body off my daily driver (99 F150 Lariat) or my two work trucks for cleaning. On both 5.4 engines I need to clean the IAC every 25 K miles, the 4.6 needed it at 120K and has almost 200K on it now. I have used alcohol, WD-40, SeaFoam, and mineral spirits cleaning the IAC with no ill effects - also none have worked better than another.

Check with your local parts house and see which cleaner is recomended for throttle bodies.

Good Luck,

T

 

check the vacume hose on the back of the intake for a leak.
To clean the throttle body use "throttle body cleaner"

 

Thank you all for your input, good info. I will post results

 

Good news, a good cleaning of the IAC and we're running like new again. Improved idle and drive-ability

 

What is the IAC? My '99 F150 5.4 is doing the exact same thing! It won't stay running at normal idle. I'm down to 400 rpm's when I let off the gas, and when I lift my foot off the gas pedal it sorta clunks and loses rpm's. HELP!

 

do a search for IAC, IAC cleaning, etc.

There's plenty of threads and many of them have pictures/tutorials.

 

IAC is an abbreviation for Idle Air Control.

This is a picture of the IAC on the back of the upper intake plenum for a 99 5.4L engine...

 

Thank you Larry. As I understand it, I have to clean the IAC somehow. Do I spray cleaner down through the throttle body or do I have to remove the IAC to clean it?

Thanks again!

Steve

 

Remove it...

 

Just wanted to thank you all for your help with my stalling problem. I put a new IAC valve in last night and it worked like a charm.

Thanks again!

 

Thanks temp1 for taking the time to post the pic . It was 2 small 8mm bolts on the top and the bottom to take off.

The part is $50 at Pep Boys... Unfortunately it was a special order and not in stock, 2 day turn around... so I was at the mercy of my local Ford dealer... $78 , really funny part was the bill says "list $85" Does that mean that somebody actually pays a HIGHER price than me at the parts counter??

The easiest way to approach on my 2000 Expy it is as you are looking at the open engine, approach from the left hand side, leaning and reaching while standing in front of the passenger headlight.

If you have the part, and the 8mm small socket wrench you can do this in as little as 15 minutes

Thanks to all above that contributed to this thread