Misfiring 4.0 ohv

[wmayo]

Got a 1998 4.0 Ranger. I thought I might have a compression problem on the left bank so I decided to do a compression check on it. I followed the manual. Disconnected the Coil Pack and Fuel Impact switch. I did the compression check and reinstalled the plugs, wire s, reconnected the coil pack and fuel impact switch. Ran rough and threw codes for misfire and coil pack. Reseated the coil pack connector and it ran ok and no more codes.


2 weeks later running rough again. Had engine check light and codes for 4+6 misfires along with coil pack. Re-seating the connector did no good, so I changed the connector. No improvement. Kept getting a coil pack code so I changed the coil pack. Engine light went away along with codes for misfires and coil pack, but it still is not running right. Rough when giving it gas, I can still feel a misfiring.

Any Ideas?

Also I was wondering if the fuel system can get air in it from the disabling and re-enabling of the fuel impact switch and then turning the engine for the compression check?

 

[97RangerXLT]

did you change out your fuel filter?

AJ

 

[wmayo]

Fuel Filter

I did not replace the fuel filter. I am not sure why it would get clogged by doing an engine compression check. I figured that whatever is wrong had to have happen because of what I had done when doing the compression check.

 

[wmayo]

did you change out your fuel filter?

AJ

Replace fuel filter and no joy.

Friend told me the ford repair manual say to drive the truck at lease 15 min at above 45 mph to reset the computer. Did that and still no joy, Engine check lights with misfire codes.

Help

 

[rangerich]

Were you able to resolve the issue with your Ranger, that you had back in March, and if so how? My 98 seems to have the problems. We Thankie!