I am starting another trend as I now have more information and am narrowing down my issue. Vehicle is a '98 E350 with V-10.

Based on Mode 06 diagnostics I seem to have miss fires on cylinders 5, 6, 7, 8. All of these coils have new boots and springs. I swapped coil 4 and 5 as they are the easiest to get to and no change.

I think the the cylender layout is cylinder 1 is the front cylinder on the passenger side and 5 is the back cylinder on the passenger side. 6 is the front and 10 is the rear on drivers side.

Some of my questions are:
Is there a circuit in the engine computer that would have these cylinders together?
Is there a harness area where these cylinders are linked?
I feel it is something like this or maybe just a bad computer.

Any help appreciated.

Michael

 

I am going through the same thing on my 99 F350 with the V10.

I have a miss on #1, #6, and #7 coils.

The spark plugs are good, the boots and springs are new.

The connections look good on the harness.

Only thing I can think to do now is replace the coils.

Good luck and report back to us.

Something to think about, out coils are 13-14 years old, they have been through many many heat cycles, probably time to think about replacing them all.

Thanks!

Jerem

 

Thanks Jerem. None of my coils are original. They have been replaced at one time or another. I may swap some more coils around and see if the missfire stays put or moves. So far it stays put.

Michael

 

I have now confirmed the plugs are snug, changed out the coils with different ones and cleaned the connection plugs for the injectors, Coils, and PCM.

I am still getting misfire readings on Cylinders 5,6,7,8. I may try compression test and leak down but otherwise I think it must be either wiring harness or PCM.

Help!

Michael