Question

2000 Ford F350 5.4L with codes P0308 and P0300. I have a bad misfire and keep getting code P0308 showing number 8 cylinder misfire. The engine has good compression and within 5% across all cylinders. Changed plug and coil 2 times and fuel injector 1 time. Hooked ground wire to plug and laid coil and plug on the engine and plug fired good. Both old and new fuel injectors ohm out good. Performed cyl leak down check. No leakage past valves, none past rings into the crankcase, and none into the cooling system. Power and grounds test well to coil and injector. Any ideas out there? Could obd reporting wrong cylinder misfire? My next step is to swap parts from cyl to cyl and see if I can get misfire to move. Any help, please.

Answer 1

P0308 Misfire number 8 cylinder

One of the common misfire when dealing with Ford is the fuel injector, at its connection it should be secured, what is commonly seen when it comes to a misfire are the injector locking tabs tend to be broken and not allowing the connection to be secure If you can remove the fuel injector connector with out releasing the locking tab this is where the misifre can commonly be. Check the fuel injector connection for secure fit use zip tie if needed.

Answer 2

P0308 FORD Code - Cylinder 8 Misfire Detected
Read more: https://www.autocodes.com/p0308_ford.html