Thread: crank no spark

97 grand prix 3.8 l non super charged

Ok here goes, just bought the car, was told did not start replaced fuel pressure regulator and started great drove for a few weeks, now it will just crank and not start. Pulled plug wire and the screw driver test and i am getting no spark. I read many posts and saw to replace crank position sensor, wiring seems ok. Still no start just cranks, no spark seen, took out icm and took to Autozone they tested it ten or twelve times, test good. put back in no, spark, checked ground from icm which seems to be located under Icm. Had to take battery out and get it charge cause i killed it with all the starting. Took two plugs out just look a little old but no fluid on them, i am getting 50 psi of fuel, give or take a pound. this now brings me to help. anyone. help...

did you replace the crank sensor?

Yes i replaced the crank sensor.

are u checking the same plug? could be a coil man.

oh, i did check at each post of the all three coil packs, maybe i am doing it wrong i take the wire off at the coil pack and hold a screw driver near it almost on it, and check for spark.

ok, did it right, have a spark tester, no joy all 3 packs. only 1 week spark, then nothing. coil packs all three test ok, .5ohm at bottom, 5000 at top. any ideas

he said hes replaced the crank sensor. ohm the plug wires, see how much resistance you have there. shouldnt be hardly any. if that test comes back ok, then i say you have a broken wire in the icm harness. if thats the case i have 3 or 4 layin around, ones yours for 10 bucks.

Originally Posted by Pittman06

check the harness into the front of your coil packs, just did one that had 4 broken wires, 3 of which was broken inside. Spliced a new connector and about 3 inches of wire and had no issues. Just another thing to eliminate for ya

yea. thats the icm harness. sorry if what i said was confusing

yup pull the loom away and start checking wires. random thought. when you changed the crank sensor did you stick the wiring back in the runner behind the plastic shield around the crank? if not your icm wiring can run on the balancer and cause all sorts of **** to mess up

thanks for the imput i will check the icm harness tomorrow, did check voltage at the crank sensor and all looked well, is there a possibility that when autozone tested the icm which they tested about tem plus times that they did not put enough of a load on it to make fail. cold weather has hit and it will be cold out tomorrow.

Ok so can anyone help with what kind of reading i am to get out of this icm harness

sorry it took me a while to post my results, after checking wires and grounds and chasing everything i decided that i need start back at the begining. So i took the balancer off and the new crank sensor off. And put it all back, put the sensor back and the balancer back, i noticed that is took a little more time to put the balancer back on. Put the belt back on car started right up.
Conclusion is the harmonic balancer was not tightened on all the way previously so, info for anyone else make sure you tighten that bad boy down all the way. If not no spark, no start, equals frustration..