99 F150 5.4 COP #4 HELP!!
#16
02-19-2012, 04:15 PM
Part 1 -Ford 4.6L, 5.4L Index of Articles
Check this site out for some diagnostic stuff you can do yourself on your 5.4, it has actually helped me a lot and now I own most of the tools that were suggested. Also, K.I.S.S. (Keep It Simple stupid). Start with the plugs and work your way onto bigger things. The COP test is pretty easy to do and checks the OHMs and you can also check other things. While your engine might seem too complicated; after a lot of research I've done and all the reading I've done since owning my truck for 30 days; it really isn't that complicated once you understand how everything works.
Not everyone is interested in learning about their vehicle from the inside out; granted, but I think it's worth anyone's time to spend a couple months reading threads/problems/diagnostics/how-tos. You will save money in the long run and when something DOES go bad... you know exactly how to find out what it is within a couple of hours or sooner. Sometimes not :P Anyways use the site above, there are other sites dedicated to the 5.4 though I'll try to find some more and add them.
Check this site out for some diagnostic stuff you can do yourself on your 5.4, it has actually helped me a lot and now I own most of the tools that were suggested. Also, K.I.S.S. (Keep It Simple stupid). Start with the plugs and work your way onto bigger things. The COP test is pretty easy to do and checks the OHMs and you can also check other things. While your engine might seem too complicated; after a lot of research I've done and all the reading I've done since owning my truck for 30 days; it really isn't that complicated once you understand how everything works.
Not everyone is interested in learning about their vehicle from the inside out; granted, but I think it's worth anyone's time to spend a couple months reading threads/problems/diagnostics/how-tos. You will save money in the long run and when something DOES go bad... you know exactly how to find out what it is within a couple of hours or sooner. Sometimes not :P Anyways use the site above, there are other sites dedicated to the 5.4 though I'll try to find some more and add them.
#17
02-19-2012, 04:40 PM
What I have not seen posted is what the failure code is.
A p0304 is a missfire.
A p0354 is the coil and supply circuit primary side.
It's important for the correct diagnosis.
What is the code your getting?
Next an ohm meter reading is of no value on the coils and system.
Reason is if a coil 'hard' fails you get a code so don't need to do a meter test.
As to a coil fails and no inbetween is not correct. It won't account for a coil with temperature sensitive shorted turns.
You cannot measure for shorted turns with a common meter.
For coil switching, there are 8 solid state switches in the PCM.
Any one or all can go bad, then you have the harness from the PCM to the coil locations.
Here you can meter the switches for opens and shorts within a spec reading if a plugin to the coil connector is used.
Can also use a 'good' clampon timing light to tell if the coil has any HV output at all.
Again, what is the code so you know which direction the fault lays?
Good luck.
A p0304 is a missfire.
A p0354 is the coil and supply circuit primary side.
It's important for the correct diagnosis.
What is the code your getting?
Next an ohm meter reading is of no value on the coils and system.
Reason is if a coil 'hard' fails you get a code so don't need to do a meter test.
As to a coil fails and no inbetween is not correct. It won't account for a coil with temperature sensitive shorted turns.
You cannot measure for shorted turns with a common meter.
For coil switching, there are 8 solid state switches in the PCM.
Any one or all can go bad, then you have the harness from the PCM to the coil locations.
Here you can meter the switches for opens and shorts within a spec reading if a plugin to the coil connector is used.
Can also use a 'good' clampon timing light to tell if the coil has any HV output at all.
Again, what is the code so you know which direction the fault lays?
Good luck.
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