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Thomas, Auto Service Technician
Category: Ford
Satisfied Customers: 364
Experience:  Ford engine , airconditioning, drivabillity and electrical specialist
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2001 ford f150 5.4 liter. The engine is missing but comes and goes.

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I have a 2001 ford f150 5.4 liter. The engine is missing but comes and goes. I thought the spark coils were wet but checked out ok. No codes are showing or any check lights. I have 3/4 tank of gas, so I don''t think it is bad fuel.
Hello Chemlex, Does the miss occur more noticeably at idle or when slightly accelerating or up a hill
Customer: replied 9 years ago.
Reply to Thomas's Post: It miss at idle and more about 1700 rpm. I just thought about plugs, i have 105k on them.
Well the common reason for the misfires on this truck are from bad coils. The plugs are due around 100,000 miles. But if you have a misfire at idle and it goes away while driving I would suspect an injector is sticking or compression problems. Away you can check to see wich cylinder it is is to run the engine. and while it is misfiring unplug each injector one buy one plugging them back up as you go to the next one. The cylinder that doesnt change or cause more of a miss fire is the cylinder that is already bad. then you can swap out the coil and plug with another cylinder and see if the miss fire changes to that cylinder that way you can rule out an ignition miss fire. Try this and let me know what you come up with.
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