I never said I was going to over look them, as a matter of fact I already did most of what's stated in those post and it has not resolved the issue, which it why I am asking a very specific question on how to TEST the coil.
To test the coil you are going to have to separate it from the ignition module.
High voltage stud to one pole of the coil (not the spade connector, the round poles) should be around 5 kilo ohms (at least on the coil I tested with my meter, results are likely to vary from coil to coil and with different meters), from the high voltage stud to either round pole.
Between the two round poles around 1 ohm, though I've seen them anywhere from 2-4 ohms on occasion.
The ignition module needs a special tester, they used to have one at Napa, though that was many years ago.
These numbers are from my spare coil. Coil tests can be iffy, I've had results all over the place. I'm usually happy with low single digit ohms to the primary part of the coil (12 volt/ground) and very high resistance between the secondary (high voltage) and either of the primary coil poles. With seriously high resistance (or no resistance) between any pole and the metal hosing.
The reason you have to separate the coil from the module is, some of the module internals ground to or through the housing and may indicate a short that doesn't exist in the coil itself.
Ohm testing a coil can be iffy anyway, depending on the quality of your meter. You are introducing current through your ohm leads while testing and inductance can cause issues with the accuracy of your measurements. That coil is designed to step 12-14 volts to somewhere around 35,000 volts. So the current you are introducing with your ohm meter and the current your meter is trying to read to determine ohms is likely to be iffy at best and maybe unreliable. In a nutshell, two different meters are likely to give two different results. neither of which are likely to be definitive.
That spade connector test point on the coil usually reads near battery voltage (usually 1 volt or so line loss) with the ignition on with the coil and module mated up (as a unit) and grounded properly.
Your sync sensor should have close (maybe 4.8) to 5 volts in, with the connector connected and it should pulse while the motor is cranking. I usually strip back a tiny bit of insulation from the wire to test, instead of trying to back pole the connector. I've never had good luck at trying to back pole connectors. Seal the bare wire back up with a dab of silicon if you are feeling anal.
Making sure the wiring is good between the CPS and the ECU is just as important as the CPS itself is.
My CPS would crap out and fail at the same stop light every morning when I drove my son to work. The third time it started running really crappy and stalled at the same spot I thought I was jinxed. It turned out to be a temperature thing with my CPS. One morning on a hunch I dumped a bottle of water onto the CPS after my motor crapped out and refused to restart. It tarted right up and ran fine for while.
Does it stall out with a steady gas pedal or when you release the gas pedal?
Second best guess is the EGR is sticking. It will only open when the motor is up to operating temperature and when you are cruising. If it sticks open when you release the gas pedal, the motor may stall and if it doesn't stall it will idle really bad.
A stuck shut IAC will do much the same as a stuck open EGR. The motor will die when you release the gas pedal, it is unlikely to idle at all.
The low voltage to your sync senor may indicate a shorted sensor. Sensors often share the same supply voltage. I'm not exactly sure which sensors share with the sync sensor. Try unplugging the sync sensor and leaving it unplugged and see what happens. Mine runs reasonably well without a sync sensor. I once forgot and left it unplugged for months and ever noticed anything out of the ordinary.
I've had a Renix since 87 and have spent maybe a thousand hours (likely more) troubleshooting and repairing stuff. I use Cruisers lists, his systematic approach and completeness may save you wasting time in the long run. Sometimes the process of elimination is the only way you are ever going to find the problem. Jumping form component to component hoping to get lucky usually gets my head to spinning in short order. And you always run the risk of building a problem into your XJ while trying to hunt down the original problem and having one of those OH Chit! moments.
Sorry about the edits, my eyes are bad and I have to reread something numerous times to pick up most of the typos and mistakes.
