Miss in 97 Explorer 5.0 CYL 7

[mduncan166]

I have a dead miss in #7 cylinder of my 97 Explorer 5.0. It started when the camshaft position sensor came apart and destroyed itself and the drive unit. I have replaced the drive unit (thing that looks like a distributor with the top cut off) and the sensor. Now I get a #7 misfire code, the vehicle misses consistantly including both idle and cruise. I've changed the plugs, wires and the coil pack on that side. I've also changed #7 injector. The compression is good in that cylinder. The plug also has a good hot spark when tested against the engine block.

Any ideas where else I could look?

[jwalker1970]

1. Have you checked if you're getting a signal to the injector. They're should be 12V+ to one wire, and a pulse ground to the other. I've tested wiring before using an inductive timing light. I pull the tape off the harnass where it meets the injector, put the (spark plug wire) loop over an individual wire while the engine is turning over. If the timing light flashes when you pull the trigger, you have a signal to the injector. If you have no signal, pull continuity test between injector plug and PCM. I could give you pinout #'s on the PCM from my reference manual if it gets that far.

2. Have you switched injectors between cylinders, and confirmed that the miss doesn't change cylinders?

3. Not to sound stupid, but as an experienced 15yr mechanic, I've done this myself.... Have you confirmed that you didn't accidently switch plug wires.

4. Did you switch coil packs side to side, and confirm the miss doesn't change. I've had Ford coil packs fire to an outside plug just fine, and miss like hell once hooked back up to an active plug.


Good Luck!!