OK I'm stumped. My son just bought this car and it runs like a champ. However, when you shut it off, it will often not restart for at least 4 hours, sometimes longer. No spark.

Crank sensor replaced. Also replaced the harness to it.

Before we bought it, the previous owner replaced: Crank sensor, cam sensor, ignition module (twice I think), and battery.

I have done the tests on the Crank sensor and seems bad, but have a hard time believing that they would just be going bad. It is getting 12v (10v while cranking). Even tried a direct 12v supply to be sure. It is getting good ground, tried a direct ground to be sure there too. I tried the LED light signal test but got nothing. Also, did the multimeter test. Only getting 1v signal back from the sensor.

Really stumped here. Ready to try a new ECM and ICM but not really sure these will do anything either.

The car runs great when it does start. I have a hard time believing that it is something getting "hot", because it shouldn't take 4 or more hours to cool down and restart.

Thanks in advance for any advice!

wires with poor connections can act this way. where are you testing the ckp output ? if its not getting to the icm test the wire back to the sensor and check out the plug

I was testing both at the ICM and right at the sensor. Getting 12v in but only 1v out during the pulse time. The plug at the ICM looked good and replaced the one at the CKP.

OK here'* an update. My son took it to work and won't start even after 24 hours. He said that the new connector is "black". Melted I guess. I haven't seen it yet myself. I'm guessing it'* getting too much power? Never tested it running. So now I'm going to install another new CKP sensor and rewire the old connector back in. Would the alternator (regulator) overcharging do this? It was putting out 14.25 volts last I checked with everything off. I did check the battery at one time and it was over 14.5 with the car off after running for a while.

If your connector is black and melted, that means high resistance due to a bad connection, the male/female connection is not tight....

I would agree. Something was bad on the new connector. Make sure you solder the wires too or it will be loose and you in the same spot again

OK. Still getting nowhere on this problem. The plug that my son thought was charred merely had some greasy fingerprints on it. And yes, the new connector was soldered in place.

Here'* where I'm at now. I have tried the 4th new CKP sensor, including one by Standard Ignition and AC Delco. Still the same results. I ran it today for 5 minutes and was fine. 5 more minutes and no restart. I checked for power and ground to the sensor and had identical readings both when it would start and when it wouldn't. However, no signal from either the 3x or 18x side.

Now I went a step further. I took the old connector (that is likely fine) and tried to get a signal with it out of the car. I supplied it with 12v and a ground directly from the battery. I can't get it to produce a signal this way either.

My new question: Can something go wrong with the sensor rings on the harmonic balancer? They do not seem to be out of round and aren't contacting the sensor. Any other ideas? I'm really stumped. Please help!!!!!

If they look straight that'* not your issue. You should be able to get the signal through the plug. I don't know what is going on there but if the icm and pcm don't see that it is not going to run

With crank sensors replaced, and the balancer not hitting them, it has to be the wiring somehow between the sensor and the ICM, if there is no 3X/18X signal....

The wiring would be my number one suspect but there is no signal even at the sensor. If I'm understanding the way this sensor operates correctly, as long as it has 10-12 volts in and a good ground, it should produce a signal, right? When it was working, it would send the 7v signal until it got to an opening in the sensor ring on the balancer.