'93 4.0 has no spark. It isn't fuses/diode/relay. PLEASE HELP!!!!!!

[Joebigfun]

OK. I bought a '93 with a bad 4.0 (the previous owner said it had bad heads/gaskets). I didn't bother to diagnose the old engine because I had access to a '93 Explorer parts truck that had a remanufactured 4.0 (need any '93 Explorer parts?). After installing the new 4.0, it cranks but no spark. I've switched out the coilpack and ign. module but no luck. I've checked the obvious things like ECM fuses/relays/diode. The coil is getting 12v at one of the wires when the key is switched on. I am a competent mechanic and pride myself on installing the new engine so that it looks like no one had even been in there but diagnosing elec. problems such as this can have me scratching my head for days. PLEASE SAVE ME SOME TIME!!! I'm sure some of you out there know exactly where to have me look. I can pretty much use a multimeter capably. Oh, one more thing. The last person in there had installed a water pump. When reassembling he didn't bother to secure the crank angle sensor wiring harness out of the way. The pulley then wore thru the outer loom and severed a few strands of the bare metal wire that runs alongside the 2 sensor wires. I did my best to re-wrap it but half the bare wires are still severed. Since the bare wire isn't connected to anything I didn't figure it was too important. What is it for?

 

[mrboyle]

Try replacing the crank sensor. The sensor controlls the trggering of the ignition coils.

 

[Joebigfun]

yup, it was the crank sensor. I was hesitant to try that since the complete engine was running when removed from the donor truck. But, as they say, sh#@ happens. The sensor musta' decided to quit when the thing was hangin' on the engine hoist. Many thanks to MRBOYLE for his suggestion. Joe