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Randall C
Randall C, ASE MasterTechnician
Category: Ford
Satisfied Customers: 12803
Experience:  35 years ASE Master Tech, Diagnostic , Electrical Specialist
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98 Ford F150: 5.4 triton V8..misses..check engine..spark plug wires

Resolved Question:

Just bought a '98 Ford F150, 5.4 Triton V8,When applying the gas, it misses, and the "check engine" light is on and flashing (if this was a '60s car, I'd suspect spark plugs and spark plug wires). Could it be just the plugs? It has been well taken care of by the former owner. Oxygen sensor? Phase of the moon?
Submitted: 5 years ago.
Category: Ford
Expert:  Randall C replied 5 years ago.

Tracer :

Hello, My name isXXXXX will do my best to assist you. I am working with your question now. Will return shortly

Tracer :

Well, i will say your thinking is near 100% correct. Ignition is ignition but.. some changes have been made.The flashing light means computer detected a miss and it is happening as the light is flashing/ Now. the most common, have done many is one the the coils is failing. Cant tell you how many we change each month. each plug has a coil on top rather than wires. They fail. they get cracks. they get burn marks in the rubber boots. in any case on is bad.Which one? that's the tricky part. You have to go to parts store and have codes scanned for free. If code has been set it will be like P0303 which is cylinder 3 P0307 = cylinder 7. If no codes set, then its more tricky. You can then only run engine at idle, mist each coil with water from a spray bottle, if you hit one and engine misses, its bad OR you can also remove each coil, look real close fro carbon cracks or burn marks in the rubber boots. OR have a shop put on scanner/lab scope and they can narrow down. This is so common I am very confident this is the problem,They run like $46+- each in my area, easy to change persay. nothing severe. Look at each coil as the wires were once there. BTW: doing pluhs at same time good idea at least you will know they are done but, rarely is a plug the problem

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