okay guys this sounds stupid because i havent found any other topics about it but my o4 f150 is giving me fits. it cranks fine, and runs fine if you dont baby it around, but if you start to baby it around say in a parking lot to ease into a spot, i can let off the gas and it will idle down and all of a sudden idle up leap forward and then idle down so low it just dies. also if its sitting still in park at a idle i can barely touch the gas and it will idle itself so low it dies. i have a k&n cold air intake that i clean regularly since last january, and checked all bolts to make sure its not sucking air through anything ive bolted up previously. it just started this a couple months ago and gotten worse since, to where now i cant drive it period hardly. any suggestions or anybody else had this problem? help fast greatly appreciated!!!

 

Check your mass air flow sensor. It can get gumed up with the oil used on your K&N filter. The irratic idle is probably caused by the computer not being able to read how much air is entering the engine.

 

x2
Also is there any check engine lights on when this happens? if the light comes on maybe find an auto parts store that has a scan tool they will let you use and try and get it to do it in their parking lot ??? just my .02

 

Do the 04+ trucks still have IACs? If so I'd start there. How many miles? You could try cleaning your MAF and looking for a vacuum leak.

Mike

 

no IAC on the 04+ trucks

sounds alot like your K&N is the culprit.


unplug the battery (& leave disconnected for 30 minutes)
clean your MAF with alcohol
get any CEL's checked for free at a Auto Parts Store

 

no check engine lights have came on at all, thats why i didnt suspect the MAF even though i have heard of oil buildup causing that. i cleaned it but kinda trying to wait till the last straw to buy a new MAF considering its around $175. I cleaned the TB, and ordered a new TB Gasket that will be in tomorrow. i guess if that doesnt work i may order a new MAF and re-install the stock intake. ill update tomorrow night and give you the news. thanks everyone!

 

i cut the top off a bottle of rubbing alcohol, and let the MAF sensor soak overnight and then air dry for a hour or so. took TB off, cleaned thoroughly, and replaced the three dollar TB gasket and re-installed everything. i think between the TB being gummed up and the oil off my k&n on the MAF i fixed the problem, knock on wood. thanks for all the input guys!!

 

hope that was it.


make sure to come back and visit us. there is lots of info around here

 

o dont worry im hooked now. glad i can brouse around to see all the topics from other ford owners. i get on every chance i get during the day. thanks