92 cav no spark, good crank sensor

[Dave S.]

I would like to change the right part, not all the parts$$$.

The car cranks fine, with no spark at any plug. The coil packs are newer, about a year old. the ecm is from a junk yard, in service for about a year. there is power at the ignition module, so it isnt a bad fuse. It has 12 volts while cranking, so it isn't loaded down by a short.

there are no obvious visible defects on the coil packs or ignition module and the connections are good. I hooked a o scope up to the crank sensor which gives a good output to the ignition module.

I suspect the ignition module, but a new one is $250.

is there a way to determine the ignition mod is bad and not the ecm module?? btw, the check engine light never came on when the car last ran. it stays on when I try to start it but I believe that is normal.

Also has a new o2, tps, map sensors.

Ideas?

[Dave S.]

I just connected a noid to one of the injector wires, no pulse. Now I assume I must change the ecm!

[4dr92cavi4cyl]

That's a good assumption, let us know...

[gina_666]

I am having the same problem, so I resorted to chaning the ECM. I put the new one in and it doesn't work or something. The directions that came with the ECM/PCM say something about a crank re-learn procedure, but the directions to do that may as well have been written in latin. Let me know what you do and how it turns out!!

[Dave S.]

I will post the results when I install the module, it may be a few days....

The last one I installed was from a like model cav, no programming required. I don't know if you can tweek a 92 ecm anyway.

[Dave S.]

I changed the ecm with a junk yard unit.
still no start, no injector firing.

[4dr92cavi4cyl]

Have you tried a junkyard ignition module?

[Dave S.]

The ignition module is next, too busy to go get it right now....BTW, which cars would have the same module as a 92 cav? baretta?sp

[4dr92cavi4cyl]

I'm not sure on the Barettas, if they we're all V6s or not. I know that if you get one off another 2.2 Cavalier from 94 back to 91 or maybe earlier, it should work.

[Dave S.]

Woo hoo! she lives!

I replaced the ignition module with a junk yard unit.
It has been garaged since May and it fired right up.

The moral of the story: the ecm unit is smart enough not to fire the injectors if it doesn't see a spark.

Now to renew the liability ins.