i have a 04 f150 with a 4.6L, has a miss at idle and also lately has a non starting issue that is sparratic..... i have done a fuel pump, fpdm , crank sensor , and spark plugs. All have been done recently in the last six months or so. I dont know what to look for next, it hasnt popped any codes or anything ???? HELP!!!!!

 

Your Idle issue may be the Idle air control valve port is clogged up or the valve itself screwing up. The EGR port runs into the same port and if it remains open at all during idle will cause crappy idle to no start.

 

The 04 has an electronic throttle - no IAC.

When was the last time you changed the fuel filter? Put some Techron in the gas. What brand spark plugs did you use, and how are the coils?

 

i used ngk plugs because thats what was suggested the coils are in good shape aswell and yes i did the filter before i even did the pump.

 

it doesnt even have any codes is the wierd thing and it seems to idle rougher after the truck has been city driven for a bit...... sprayed around a bit with carb cleaner to see if possibly a vac. leak, but nothing. I'd do the coils but that can get expensive and i doubt thats the reason why it wont start here and there.Im thinking what ever is wrong is causing the no start and the idle problem but i am an amateur and dont know much which brings me here...????? the truck has 101,086 mi if thats any help.

 

I'd recommend you put Motorcraft plugs back in it.

 

ehh the plugs arent the problem

 

Ehh?

Whatever.

How do you know? Do you have a $6000 stress tester in your garage?

They may not be. Did you use dielectric grease when you replaced them? Did you use a torque wrench and tighten the plugs to 28 ft/lb?

 

Always use dielectric grease on plugs ..... beginner not stupid. The reason i say its not the plugs is that i have the same problem now as it did before the plugs were installed.I've always had good luck with NGK run em in everything i own. I also draw the conclusion that the coils are ok because if one was bad it wouldnt cause the totally random non starting issue ive been having. In that being said the misfire problem is at random aswell, which if the coils were shot it'd have the misfire all the time or more often then not.Again not the case here. Today after i came out of work and it didnt start again, seems like its not getting fuel. So i left it for an hr or so well i went to get carb clean to confirm that it was fuel related and when i came back the son of a gun fired right up! I think its fuel related because last time it ran this way it was the fpdm and thats been replaced twice,fuel pump is pretty new,crank sensor is pretty new idk wtf else to look @ i need some help.

 

Also if the coils were bad wouldnt it misfire under load aswell? just trying to look in the right direction here.

 

I'm not going to say that the plugs are your problem, but a friend of mine is a Ford Master Tech and he told me that he'd finally learned his lesson about putting anything except Ford plugs back in a Ford modular motor. (And trust me, this guy knows his stuff.) I tried NGK plugs in my son's Grand Marquis with the 4.6 and they ended up coming out 2 months later due to driveability issues. The Motorcraft plugs smoothed it right out. And I've never had trouble with NGK plugs in anything I own.

And I wouldn't rule out another FPDM. If they didn't mount the new one with the insulating washers, it will rot out just as quick. When it starts to go though, it usually kicks a few codes.

 

no codes and i did do the update kit module with the spacers to keep it off the frame. The reason im stuck on the prob not being the plugs is that its doing the same thing now as it was before i even did the plugs a sparratic rough idle not all the time. After reading basically all the TSB's on my year and make im startint to think it could be pcm? whats your take?

 

and as i mentioned above it wont start sometimes aswell also a problen that i dont think the plugs would cause.

 

alright so i just installed a new cam sensor lets see if this fixes the problem,also purchased a inertia fuel cut off switch aswell that im going to install. when i was down there i noticed some water below the fuse box in the cab ! the cut off switch wire run right towards the puddle this also may be the problem if this is causing a short. this is retatded!!!! ill keep ya posted.