Hi all. New to the board and just traded in my '04 f350 dually for an '04 f150. It's a supercrew 5.5 bed with 77,000 miles.

Truck has a little bit of a rough idle. It also has some off idle valve chatter if I put my foot down from a dead stop. It also does this just before a down shift if I'm gettin' on it.

Other than that I love this truck. Rides and runs great. Any suggestions would be welcome.

Jeff

 

Sounds like an IAC issue with the idle, and maybe it's a spark knock caused by a dirty MAS and throttle body.....

 

MAS? Is that Mass Air?

And where is the IAC located?

Jeff

 

MAS = Mass Air Sensor.

Do you have the new body sytle 2004 model, or the old body? More importantly, do you have the 3v or the 2v version of the 5.4 motor? If you have the 3v version, then there is no IAC, as it has electronic throttle control (fly by wire).

 

It's the new body style with the 3V.

Looking for any suggestions on what to clean or check to maybe get rid of these 2 issues.

Should I run some Seafoam through the PCV or booster line?

How is it recommended to clean the throttle body?

Jeff

 

Just to see if it's spark knock or something else, run a couple tanks of full premium gas through it - if it's spark knock the chattering will stop.

 

Put some 93 in this morning and all chatter is gone. Is there any other fix for this other than runnig 93 all the time?

I'm running an SCT with tunes from Innovative Diesel on the 87 tune. Should I leave it alone?

If I remember correctly, When I ran the 93 tune with 93 in the tank I had some chatter then also.

Jeff

 

Try 89.

Talk to your tuner or put the stock chip back in.