i own a 98 4x4 orp,5.4. when i am sitting at idle its a little rough.its not to bad but i dont like how it feels.is this common?and how can i fix the problem?

 

Take a long screw-driver, grasp it by 'blade' and(with the eng. at idle rpms) 'tap' the IAC 'can' with the handle. If the idle 'clears up' then the IAC is dirty/clogged up or worn. I haven't had too much luck cleaning one--the rough idle usually returns--but it's easy to do. Unbolt and unplug it, then spray a good solvent inside it and then shake it--there'e a valve inside that will 'roll' back and forth--clean it out as good as you can. Hook it back up and try the idle again. A new one was about $45 for my 97 4.6L.

Check your throttle plate for burned oil stuck to its edges--3M and others make a solvent that won't hurt the teflon coating in the throttle body.

How 'old' is your fuel filter? Should be replaced every 15 or 30,000(I forget) miles but I kinda doubt this is the culprit.

Dan

 

where is the iac can at?and what is it?

 

good question Donnie. my truck idles a little rough too, I wouldn't mind giving this IAC thing a rap, if only I knew what and where it was. Anyone? Thanks...

 

your problem may or may not be IAC, my 97 F150 has had a intermited rough idle for one and half years. The dealer can not fix it, I replaced the IAC, EGR and cleaned, poked and did everything I could. Some of these trucks don't like to idle...

For more information check out the F150 Rough Idle Web site

http://home.pacbell.net/donw35/f150

 

I haven't had the hood up on my 97 4.6L in a while so I'm not 'sure' but I think it is on the left side of the throttle body. It's a bright metal 'can' about the size of a tomato paste can. Held on by two 10mm bolts and has an electrical connecter on it too--I think.

You might want to look for coolant dripping onto the #4 coil pack too. Some have found one of the heater hose clamps allows coolant to seep out onto the coil and short it out.

Dan