Need some help.... 126000kms on 03 explorer 4.6 truck started
running rough at idle and under load.... code came up for cyl 8
injector. Replaced injector... problem still there. Switched cop
and plug with another cyl and plug.... same code and cycl 8 is definitely not working. Would a generic problem always affect
i cylinder. Read lots of threads but can't find my problem. I even checked wire clip on for injector... it appears ok. There is power to
injector wire clip.
Any help would be appreciated.

 

Misfire can be caused by many things.

Plug, cop, FI, too lean, too rich, bad valve.....

What was the colour and condition of the plug?? Photo might help..

What was the code you recovered????. ....Philip

 

thanks for the reply... plugs all look the same but should be changed. I switched
a couple of plugs and cop's around and the same cyl.8 is still not functioning.
injector wire clip looks good and has power to the injector. Cylinder 7 now has all
of cyl 8's parts and works fine.... still have 308 code on cyl 8 injector

thanks for any replys.... Rob

 

Either do a leak down test on cyl 8, or connect a vacuum gauge and validate the engine mechanically..... Philip

 

replaced cop on 8cyl and plug and injector....just to eliminate the what if
new code has emerged p0208 and 308 which i guess is caused by 208??
316 also appeared detected misfire in first 1000revs

another thread had same problem and solution was clean the throttle body??? I am going to clean it but could that be the problem???

thanks for any help

 

You may now be getting somewhere. Per the factory service manual, the P0208 is defined as, "The comprehensive component monitor (CCM) monitors the operation of the fuel injector drivers in the PCM. The test fails when the fuel injector does not operate electrically even though the harness assembly and fuel injectors test satisfactorily." The service manual lists only one possible cause of this code, "Faulty fuel injector driver within the PCM." Unfortunately, that code points to a bad PCM.

This truck will have PATS so unfortunately I don't believe you can get away with just installing a salvage yard PCM, the PCM will need to be mated to the PATS system and other systems which requires the Ford WDS or NGS system.

-Rod