My truck seems to be missing on occasion. Both the plugs and wire have been replaced in the last three months - have less than 5000 miles on them. The ignition module was replaced by the original under warrenty (dealer did it).

It does it at lower RPMs, under small loads - going up small hills. It seems like it does it when its in over drive, or if I step off the gas, and back on lightly heading up hill.....

Anyone have ANY ideas?

Thanks,
Robbie

 

Bad gas? Just a possibility. It's never happened to my F-150, but it did to one of my Rangers. I think it was just underpowered, though.

 

it could be the MAF (mass air flow sensor). well thats what it was in mine.

 

There is a fairly common problem with the spark plugs and wires on these trucks. The symptoms of it sound just like what you are describing. Make sure that your plugs and wires were replaced with the proper Ford parts and not a substitute. Even that is no guarantee. I have read a couple of posts from people who replaced plugs and wires and shortly after have had to do them again. Spray a little water on your wires in the dark with the engine running and see if you can see any arcing or hear the engine stumble a little. Pull the plugs out and see if you see any arc tracks down the side of them. Give the wires a bit of flexing while you have them off. If the problem is worse afterwords, it indicates that the carbon cores in the wires are breaking down. I had a similar problem myself and Ford could not diagnose the problem but a private garage went through the procedure that I just described and found that the wires were breaking down. That happened at 70,000 kms and I have about 145,000 on it now and it has had no repeat failures. Good Luck, GlennMc.

 

I just replaced the wires a few months ago - they can't be bad already, and they weren't cheap wires either - Bosch, I think they were $40 or something. Bad gas would be my guess too, but I've gone through a couple of tanks and it continues to do it.

The only thing with the MAS that has been changed is the PoBoy FIPK I did a few months ago.

Robbie

 

what about the fuel filter. mine was struggling with hills and while pulling a small trailer last summer. changed the fuel filter and it seemed to get better.

 

Did it start doing this when you did the Poboy FIPK mod? If it did, I would backtrack each step you took to do this mod. Your problem may be just an air intake related problem. Just a guess. And I think it could also be a bad fuel filter like wildchild said. Or if it's not that, have your fuel pump checked out. It could be your fuel pressure making it miss like that also. Again, I'm just guessing. Hope this helps.

 

The truck didn't start doing that for a good while after I did the FIPK.....I will try the fuel filter - its on the frame rail isn't it? That was my only other conclusion....

Robbie

 

RWillieK
If it was a plugged fuel filter, you would suffer fuel starvation mostly at high rpm when you require a lot of fuel. Don't give up on the wires or plugs yet. Do as I described previously to rule them out or prove them as a problem. Nobody can diagnose your problem without looking at your truck and that means you or your serviceman will have to do it. If it is not the ignition, (and it won't cost you anything to test it) then move on to your fuel system etc. Make sure you do things methodically or you will spend a bunch of money on parts before finding the solution. Does your truck do this when cold or does it have to warm up before missing? If it has to warm up, it also indicates the heat related breakdown of an electrical component. Good Luck, GlennMc.

 

yes the fuel filter is on the frame rail.
i would have to agree with glenn mc about checking the elec first. doing the fuel filter certainly won't hurt your truck,(should be done every 15,000) but it sure is a pain. not too pricey either but you will need the quick disconnect tools. they are between $1-5 depending on whether you get metal or plastic ones.

 

WHAT????... NO WAY IS IT A PAIN! takes me less than 10 minutes to do. disconnect fuel shut off switch, start engine till it dies to relieve pressure, use disconnect tool and disconnect both sides of filter, pop old out and pop in with the new, push fuel lines back on new filter, reconnect fuel shut off switch... done!

 

welcome to the f-150 world. Read on and maybe you will find what you are looking for. Everyone has about the same problem and have tried alot of things maybe one will fix yours but dont count on it.

 

I put Bosch Platinum Plus 2's in my truck today - fixed the problem for now!