So I recently got a 99 expi and it had a miss. I figured it was a coil pack so I got 2 new(used) coils and replaced the 2 in the truck. Well nothing changed. I swapped coils again and nothing. I started taking plug wires off to see if I could see the spark jumping. Well I found the driver coil firing cylinders 2 and 8 won't fire. The wire controlling that coil looks ok and isn't visibly damaged.

Does anyone have an idea where to go from here? Could the computer be bad? Does anyone have a wire diagram from the computer to the coil so I can make another wire to test with.

 

See the attached PDF.

 

Thanks for the file. That is a good start to tracing the wires and connectors for possible corrosion or breaks

 

must be hard to reach pass side rear 2 plugs....i never tried myself. you do them yourself???? im sending mine out this minute for plugs and lower ball joint.....

 

They do look difficult to do but I haven't gotten that far yet. I planned to do them soon but I want to figure out why the driver side coil isn't working first.