Ok, I tried searching for about 20 mins, nothing for an '04 up. What is the stock idle speed supposed to be for my '06 F150 with the 4.6l V8? Mine is at 500rpm and this just seems low. I am assuming this is why it shakes when I am coming to a stop.

 

are you talking about when you stop with it still in gear, or when its in park?

When I'm in park and the engine is warm mine is around 650, but when stopped in gear, its around 500.

 

That sounds about right, at operating temp in gear. There's a calibration update for some 5.4 3Vs that bumps the hot idle up a tab, makes them run a little smoother. I don't think there's one for 4.6s though.

 

Well, I am at 500 at BOTH park and in gear, maybe a touch over 500 in park. But my truck shakes as I'm coming to a stop right when it drops down to 500rpms, do you notice anything like this? And this is with the engine warm, when cold it will be up around 7-800 in park, not sure about in gear.

 

ive notice is, mines dosent shake but i know wat u mean, mine does that sometimes.

 

Hmm, yeah that does sound a little low. I know when I start mine cold it stays above 1000 for a while...

Might be your mass airflow sensor, but thats just a guess.

Make sure your air filter isnt clogged also.

 

Yeah, I think it seems low. I cleaned the MAF and put a new K&N filter in a while ago, no improvements. I've read a dirty IAC can do it, but not sure how to go about cleaning it. I used to have a '97 with the same motor and it was always up around 7-800.

 

To clean the IAC, just unplug it and pull it off. On the side that bolts to the engine you can spray carb cleaner down it, let it soak for a few minutes and then dump it out. If you have one, use an air nozzle on an air compressor and blow it out afterwards.

 

.. is the A/C on when it'd idling at 500 RPMs? That seems low, if so.

 

My '05 idles around 500 or so - but does it pretty rough. That's in park w/o AC on.

My RPM gauge usually says right at 500 while the Edge reads around 525-530 while this is going on - after I get my emmisions done tomorrow I'm going to experiment with setting my idle to around 650-700 and see how that goes.

 

When mine is stopped and in drive its like 556

 

My 2004 5.4 idles around 525 rpm.

 

mine idles at 800 in park and around 600-650 in gear currently. i asked for my tuner to boost my idle over stock though. the sound system and other toys stress the alternator at low RPM. it idles perfectly how i want it to.

 

Ok, but which one is the IAC? Is it the small part on the right side(looking from infront of the truck), or the larger thing on the left of the throttle body?
Thanks.

 

No AC...