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J EARL
J EARL, Ford Technician
Category: Ford
Satisfied Customers: 292
Experience:  17 YEARS OF FORD DEALERSHIP SERVICE FORD SENIOR MASTER ASE L1 DRIVABILTY TECH
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2005 ford f150: warms..Check engine code a couple times was misfire #4

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2005 ford f150 5.4l missing when cold. Runs good for the first 10-15 seconds then idles down and starts missing, after it warms up for about 10 minutes it runs good. Check engine code a couple times was misfire #4. Comfirmed this by pulling the plug on the injector at #4 and no change when it was missing.

Tried new plugs,cop, fuel filter, injector on 3&4, cleaned MAF. ????
hi my name is XXXXX XXXXX ill help you today it sounds like you tried alot of stuff the next step would be to check compression of the engine i would suggest that whole bank that your having a problem on you may have a burnt valve causing low compression on that cylinder do the test and let me know how you make out thanks jeff
Customer: replied 6 years ago.
I was thinking along the lines of a compression test also but this was not a gradual problem, just started up one afternoon. Since it seemed to run fine until 10-15 sec after cold start it seemed something electronic is giving bad info. I have a new upstream O2 but have not installed it yet because it is 100$ and I learned it only trims fuel settings down from preset value after warmup is that correct? Also there is the vct possibilty?
a vct concern will affect a whole bank not one cylinder the other thing you can try is installing a noid light on #4 injector and watch injector pulse when the truck is misfiring
fuel trims set check engine lights very quickly and again will affect all cylinders on one bank
Customer: replied 6 years ago.
Don't have a noid light but I did replace that injector.
a noid light is inexpensive you can pick one up a sears you may have replaced the injector but how is the signal to the injector from the pcm you can watch the light flash every time the pcm sends a signal to the injector. you can do this with the ignition coil as well by the way did you swap coil and plug from 3 to 4 to see if the skip follows?
Customer: replied 6 years ago.
I bought 2 new coils and replaced every coil at least once swapping them out with no change. I was thinking about ordering a new set of 8 cop online for about 100$ so I could swap all out at one time. It is hard to tell where the miss is when swapping stuff around because it messes up the computer it seems. I had coil problems on wifes 98 exp once and had to replace 3 of them to get the rough out! Good advice on the noid, will check local sears. I was hopping it could be the computer and not a head that would need some serious bucks, this truck only has 66k. I read that Ford had a recall on these fuel injectors so maybee that would have burned the valve/

Nice coyote by the way, with bow?
thanks yes with a bow thank you for reminding me about the recall on the injectors what is happening is that the are sticking open allowing fuel to enter the cylinder most of the time just fouling out the plug but if its bad enough i have seen it hydro lock a cylinder bending the connecting rod causing low compression
the engine will have low compression on that cylinder you will need a special adapter for your compression tester because its a 3valve motor but definitely check compression first if you still have the faulty injector its probably under warranty hope this helps if it dose please hit the accept button if not please ask more questions Jeff
Customer: replied 6 years ago.
Allright well I have probably used up more than 15$ of your time, will look into the noid and when I do it what should I look for? inconsistent pulses or no pulses? will also have compression checked.
see if when pulses become inconsistent and skip happens if its at the same time good luck
J EARL and other Ford Specialists are ready to help you
Customer: replied 6 years ago.
Thanks
Customer: replied 6 years ago.
#4 cyl was at 30% so it's bad. Now the why and will ford warranty, its at the ford shop and they are pulling the valve cover to see if a rocker arm is off, I doubt it because it will run OK if warmed up some. I suspect a bent rod from fuel leaking down, or scored cylinder.
YOU PROBABLY HAVE A BENT ROD IS MY GUESS ASK THE SERVICE DEPT TO RUN YOUR VIN TO SEE IF YOU HAVE AN OPEN PROGRAM ON YOUR FUEL INJECTORS TO SEE IF FORD WILL COVER THE REPAIR LET ME KNOW JEFF
Customer: replied 6 years ago.
Yep I already brought that up with the shop and it is covered up to 120K on the injectors and I am at 66k. Service manger said he suspected the injector but are still looking into it, will let you know.
Customer: replied 6 years ago.

2 broken valve springs at #4, engine comming out and valve job/new springs on both banks.

 

Cost around 3k$.

Can they change the number 4 valve springs without pulling the engine?

Customer: replied 6 years ago.
I asked that and they said no. I think I could have if I had the time, maybe remove the cam, then it would have been a "seller or trade in". I like the truck so will have it fixed for the long haul.
I would have all the springs changed and while they have the engine out have them look at you exhaust manifold bolts, this is another problem area.