98 SL1 Intermittent No Start/No Fire At Plugs

[HeinekenHazed]

My wifes 98 Saturn SL1 has been having an intermittent no start condition for the last couple of months and up until now I've never been able to take a look at it when it was actually not starting. The car has high milage (130k) but it runs great when it starts which is most of the time. Severl time a week it just won't start but it never fails to fire up if you give it a few hours and try it again. When I put the spark tester on the wire there was no spark, it would'nt jump the gap. But after an hour or two it checked out fine again, 25,000 volts in order to jump the gap on most testers I think. I ran most of the suggested tests from the haynes manual (except the electrical schematics don't match up at all, the only ones at the back of the book are for pre 96 models). AHHHHH!!

Anybody have any ideas??

Thanks, Josh

[sierrap615]

a faulty crankshaft position sensor sounds like a healthy bet to me. when they begin to fail, they tend to become temperature sencetive

[HeinekenHazed]

Thanks for the suggestion, that was one of the few test I did'nt try, I was haveing a real difficult time of trying to back probe the sensor the other day. Should'nt I be able to at least initially test that by probing the wires leading to the sensor, if I could find them( I belive they are yellow and purple). If all else fails I guess I'll just take the sensor off and test it.

Thanks again,

Josh

[sierrap615]

with a bad crank sensor you will also have no injectior pluse along with no spark. use a NOID light to check for a fuel injectior pluse(they are easier to get to then the crank sensor), if you have pluse but no spark, the sensor is good(bad ignition module?)

[HeinekenHazed]

I had already used the noid light and all injector pulses were fine...I also finally got to the crank sensor and resistance checked out good. The only diagnostic test in my book for the ignition module says it only applies to 95 and earlier models. Does that mean I'm going to have to take it somewhere or is there some other way to test the module?

Thanks for your help,

Josh