We have a '88 YJ with a '89 Cherokee 4.0 I-6 engine / transmission transplant. Our symptom is as follows: Jeep ran fine, parked overnight, next morning hard to start and idled rough - didn't drive, next day won't hit at all.
Things we've done:
New coil, plugs and wires, fuel filter, verified timing and top dead center, ignition module tests good (not sure I trust the test), CPS was replaced less than 500 miles, and three months ago.
Engine won't even try to fire even with ether straight into the throttle body. Spark looks weak when checking via grounded plug?
It does look great in the driveway!
Ok, new ignition module and another new Crankshaft position sensor just in case. Next step, the computer. Does any one know if the computer can be tested if disconnected and carried into the parts store?
Things we've done:
New coil, plugs and wires, fuel filter, verified timing and top dead center, ignition module tests good (not sure I trust the test), CPS was replaced less than 500 miles, and three months ago.
Engine won't even try to fire even with ether straight into the throttle body. Spark looks weak when checking via grounded plug?
It does look great in the driveway!
Ok, new ignition module and another new Crankshaft position sensor just in case. Next step, the computer. Does any one know if the computer can be tested if disconnected and carried into the parts store?
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