1993 Other Jeep Models 6 cyl All Wheel Drive Automatic 297000 miles
We recently got a 1993 Jeep grand cherokee. This truck is in great shape however stopped running. We have done some checking on it and found that there is pressure to the fuel rail, The ASD relay is working as when the ignition is first turned on the relay clicks and there is power going to the coil. The power lasts there for about 3 seconds, then goes away. Also we have traced the wiring diagrams and found that the coil is a 2 wire system, one ground one power, and the ground goes directly to the ECM. The ECM is not putting out a ground signal to the coil. So now the coil has power for 3 seconds when ignition first turned on then goes away, and no ground from the ECM until the ignition is turned off then will have ground for about 3 seconds. We have changed the Crankshaft position sensor, the ECM, and the coil with still no luck. Also when we engergize the coil directly with a positive and negative jumper wire, the truck will still not start and we can't figure out why. Any suggestions and ideas you can offer would be appreciated! Thanks again.