QuestionQUESTION: getting dark here now so i may have to take up checks again tomorrow. there seems to be steady voltage at the single wire going to the distributor. the ASD relay checks good for continuity throughout and by hooking it to battery voltage to verify operation, so it's not fused shut. playing devil's advocate, if my ground path as you described proves to be good, and there is voltage at the single wire going to the distributor, could i ASSUME (we both know what that means but it's my best option these days! lol.) the distributor/coil could still be bad even though it checks ok resistance wise? having an electronics background i'm having a hard time thinking a wire just "went bad" while she was driving, although possible. inclined to blame an actual "part", just dont know whether to take a chance on a distributor or PCM! thanks for your time, if we fix this i'll get my wife to fix you some pecan pie muffins to drop in the mal! :-)
Jon
ANSWER: PS:
You said the paper spacer on the crank sensor was still there...It should show some signs of being worn away due to your cranking the engine over. It suggests to me that you may not be getting pulses from the sensor (and certainly if you were you should be able to see them on the sensor signal wire) because you don't push its face down and hold it there when tightened the retainer screw. The spacer is supposed to wear away and leave the proper spacing to produce a pulse. So make sure you do that pressing down when you tighten the retainer.
All I can suggest is that the ASD should not be staying closed while you are cranking it over if it is not getting signals from the cam and crank sensor. And if it does stay closed while you are cranking it then the PCM must be getting signals from those sensors (unless the PCM has failed and is grounding the ASD coil nonetheless. You can check fuse 1 in the power box as that too gets its voltage from the ASD. I don't see any other way for the spark coil to get 12v on the single wire plug unless the ASD were closed while you are cranking. But in any case there is nothing wrong with the ASD being closed falsely, that would be a safety issue. The question is why no spark. You could look at the gray/black wire on pin 5 of the 6-pin plug to see if it is oscillating between 12 and 0V when you turn it over by hand (maybe it would sit at steady voltage some where between 0 and 12 if you used the starter motor, which would show it was pulsing by not slow enough to detect the individual pulses). If you get that, and still no spark pulses then the spark coil has to be bad (or of course the rotor could be bad or the distrib cap but those were also replaced. You could eliminate those latter by removing the cap and checking for spark at the coil output that mates with the cap.
Good luck. I'll take the muffins!
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QUESTION: the spacer did show some slight signs of wear, but i'm not sure how quick it would actually wear off with the engine not actually running, just cranking a few tries then stopping. i was pushing it as hard as possible before tightening. the ground wire from PCM to 6 pin connector is good BUT, i did want to check the voltage at the single distributor wire to make sure i had a steady voltage from the PCM, and i do, but it's only about 10 1/2 volts, even jumping with another vehicle to make sure i had a full battery voltage to start with. what would keep it from being 12 volts, and would the weaker voltage keep it from providing any spark at all or just make it a weaker spark? because i have never even seen a hint of spark yet.
AnswerHi Jon,
The ASD relay contacts could be oxidized, or any recipient of the voltage could be dragging it down: the oxygen sensor (though it is protected by fuse 1 but you could pull that fuse and take the sensor out of the circuit to test that), the generator field coils which which you could unhook, and the distributor/fuel injectors (which you could unplug to see what effect that has on the voltage level. Probably the easiest place to look at the voltage output of the ASD in fuse 1 in the powerbox. Sure, a lower voltage than 12.5 would proportionately reduce voltage of the spark output of the distributor to the point of no spark possibly.
Roland
