Ford 5.4 engine miss

   / Ford 5.4 engine miss #11  
I get a blank screen with the scanner. No reading whatsoever. Makes me wonder if its a computer problem.
First thing - check your fuses. The reader port is on the same fuse as the cig lighter. If that is blown, you will get nothing plugging in a reader as there is no power to the port. Ancient SD trick :)

Then keep a reader with you for when you have the problem crop up.
 
   / Ford 5.4 engine miss #12  
when was the last time the fuel pump was changed. i would get the pressure checked on it at least i have changed more fuel pumps than i would have liked, i have a 3rd gen camaro waiting for me to put pump in and there no worse car than those. gotta drop the rearend and exhaust just to get the tank out grrr . and dont worry about unhooking the battery to clear the codes, obd2 will keep the trouble codes even with a loss power unlike obd1 computers. they have to be cleared through a scanner. check the fuse for your port.
 
   / Ford 5.4 engine miss #13  
THose coil on plugs are notorious for startin to die around 80-100K Anything past 100K is a bonus. I've seen some hit 200, but they're a commonly failing object due to heat and age. Get your scanner reading, or try another scanner; it should point you in the right direction. For what it's worth, there some newer cheaper ones out there now that can record. I think it's autox-ray and they've got one that will log it, so you hookup and drive around, then can download the info back to your PC. It also has some basic diagnostic tests. Worth the few hundred if you've got a obd2 vehicle you're going to maintain yourself.
 
   / Ford 5.4 engine miss #14  
Not sure if you have coil on plug, but if so I would guess you have an intermittent "COP" going bad or a plug wire that is shorting out. New plug wires do go bad. At 110K, when the first COP went bad you should have changed them all. I would keep the scanner in the truck, possibly even hooked up and read what going on when it misses.

Wedge


A COP is exactly what I would suspect. I also have a 2000 F150 with the Triton 5.4L V8 engine, which has the COP packs on it. My first one went bad at about 60k, have since had about 3 others to go bad. At 170k, I think another one is intermittent now. It seems to misfire at times, but if I park it for a few hours it seems to clear up. Will just keep running it until something happens, hopefully if it's a COP it will give up and quit altogether and I'll be able to look at the diagnostics and tell which one it is. My experience is that the computer doesn't log a code UNTIL you see the check engine light is lit up. Then you should be able to read the code off of it and tell which COP is bad, if that indeed is the problem.
 
   / Ford 5.4 engine miss
  • Thread Starter
#15  
Cig lighter works but still get a blank screen on the scanner. Scanner works fine on the car.

I can check fuel pressure but in my experience when an elec fuel pump is bad it just plain quits.

I haven't had time to check the coils. My Lincoln has 170K+ miles on it and has only had one coil replaced. Actually the coil was good but the boot was bad and the parts store was out of boots so I just bought a coil with a boot. That was probably 50K miles ago. I've also got a '95 Grand Marquis with low miles but lots of years on it. Still has original coils and runs great.
A Ford mechanic told me the boots start to go bad when the plug gap opens or the plugs are fouled.......and the coils go bad if the bad boots aren't replaced. As soon as I get time I'll test the coils. If they check out ok then I think the computer is the next logical thing to look at.

I'll post back with results.
Thanks for the help!
Pops
 
   / Ford 5.4 engine miss #16  
While the boots on COP can cause a problem the biggest issue is heat. I still think you have a coil breaking down when it gets hot. I would buy one more coil and start at the plug that is closest to a heat source. Try it for a few days then move it to the next plug if necessary. Usually the plug right by the exhaust manifold is the culprit.

I can not explain the scanner not working.

Chris
 
   / Ford 5.4 engine miss #17  
Verify what fuse the diagnostic port is on and check the fuse.

Have you change the fuel filter? With a miss under load that is the first thing I would check.

Don't throw money at it until you can get a decent diagnosis. Misfires will almost always throw a code.
 
   / Ford 5.4 engine miss
  • Thread Starter
#18  
Verify what fuse the diagnostic port is on and check the fuse.

Have you change the fuel filter? With a miss under load that is the first thing I would check.

Don't throw money at it until you can get a decent diagnosis. Misfires will almost always throw a code.

Changed the fuel filter.
10-4 on checking the fuse.
 
   / Ford 5.4 engine miss #19  
Verify what fuse the diagnostic port is on and check the fuse.

Have you change the fuel filter? With a miss under load that is the first thing I would check.

Don't throw money at it until you can get a decent diagnosis. Misfires will almost always throw a code.
Actually the Ford COPs are notorious for going bad without throwing a code until they completely fail.

And yes, actually check the fuses, despite the cig lighter working. I don't know the fuse number on the earler SDs for this. It is also possible that your reader may not work on this SD. Trucks over 8500 lb GVWR are not required to meet OBD II computer standards, and I recall (dimly) hearing that early SDs (the line started in 99) were not totally compliant. High end readers should be compatible, but probably not all the basic ones.
 
   / Ford 5.4 engine miss #20  
Pops15, can you tell me where the fuel filter is located at on the F150's?? Extended cab models, if that makes any difference. Thanks.
 
 
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