ok i am new here i have read alot of forums similar to mine but still no help to start i have a 06 f150 with the 5.4 ran fine till a week ago starting missing bad pulled po303 code so i went and got injector cop and a set of motorcraft plugs changed all still no different baught another cop to put on other cylinders nothing changed took throttle body off cleaned it put new maf sensor and checked the pressure reg no help the conts only have about maybe 300 miles on them im lost oh also did a vaccum check it was fine did a comp test all cylinders are good so it has no code now so i hooked up scanner tried checking each cyl for missfire none were all checked out fine it does have a little tick sounds like under intake but i think its always had that any other ideas thanks oh sorry i also checked o2 sensors they checked good im lost but it idles real rough backfires and has straight fuel smell out exaust thanks for any help and sorry for long wind just tried to get everything in that ive done

 

Is it shuttering hard at idle only? If you put down the gas pedal does your engine seem like its running fine? If so its probably the idle air control or iac. Don't throw parts at it get down to the root of the problem it will save you money I'm the long run. I hate to say it but sometimes it pays to take you vehicle to us dealership guys. Hope the best for you let me know what turns up.

 

yeah it seems to run fine one the rpms get up i didnt throw no money at it it was due for plugs anyway and i baught injector first cause i new they were bad for that it got a little better after injector but i app your info is there a way to test that im on a fixed income now so i dont have money to pay the dealer i was a mech for 7 years i dont get stumped much but this one got me

 

well iac is dealer only and they want 279.00 bucks for it but i was told if it is that it should whisle and stop its its unplugged is that true

 

Hmmm. Get a small ball peen hammer and smack the iac a few times not TOO hard. See if that helps free it up. Sometimes they just get stuck. Sometimes if your dealer has the part in stock they will let you buy it and return it if its not right so maybe try buying it and seeing if it fixes the problem. Or try and find a salvage truck and take it out. Is have to physically look at it to determine definitely the iac or not.

 

ok ill try that thanks i will keep you posted i guess i should ask just to make sure it is the one on the drivers side on the throttle body right i really app the help alot

 

well i did the ball peen thing no change so i also went ahead pulled injectors back off had freind turn key on seems as i had another bad one on number one cylinder it revs alot better idle is still rough so im gonna go grab another pair of those oh so exspensive plugs ill let you know if that fixed it

 

Didn't you already replace the plugs? You shouldn't have to put more in if they are recent. Have you checked all the injectors?

 

yes i did replace all plugs but pulled the one out of cylinder one and it looked fauled already thats the one that i think the other injector was bad on i did the ohm test on all injectors they are where the same but that one looked like it was bad

 

all were the same except for number one i mean thats why i changed it