We have this 1999 Ford F150 5.4L. We replaced Spark plugs and fuel filter. Vehicle has a misfire when you accelerate only, than it goes away. Fuel trim levels dont go over +10 or -10 at idle or cruise. CKP signal looks good, Fuel injector pattern good. Fuel pressure is 30PSI KOER within spec. Current ramped fuel pump and ignition coils look good. No MIL light, check with $53 every cylinder passed misfire. Cleaned MAF.
1999 Ford F150 5.4L Misfire
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if this is the coil on plug system; i'll bet you have a bad coil or two. you will need the ford cop adapter from snap on. i get these all the time; on one i had to replace seven coils, the customer did'nt believe it until they drove the vehicle. don't rely on the engine light or mode 6 to tell you which cylinder is misfiring. with the cop adapter and the vantage or vantage pro you will easily find the misfire. -
We have this 1999 Ford F150 5.4L. We replaced Spark plugs and fuel filter. Vehicle has a misfire when you accelerate only, than it goes away. Fuel trim levels dont go over +10 or -10 at idle or cruise. CKP signal looks good, Fuel injector pattern good. Fuel pressure is 30PSI KOER within spec. Current ramped fuel pump and ignition coils look good. No MIL light, check with $53 every cylinder passed misfire. Cleaned MAF.Comment
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