Won't start, I'm clueless....

[Pu241]

Add 1 rep!

Good idea!

[FestYboy]

now that's interesting, if he was getting weak spark before, how would changing the controler affect the condition of the spark? that is now that i think of it, that there was some resistance in the ground circuit, but again that shouldn't affect the spark strength.

[kellcomnet]

same dang thing on redfesty...weak spark,replaced the ignition module and bam fired right up.she is running finally, all that is needed now is some internal wiring, that is supposed to be in route. then I need to find a meet in the tx/ok area.

[Pu241]

now that's interesting, if he was getting weak spark before, how would changing the controler affect the condition of the spark? that is now that i think of it, that there was some resistance in the ground circuit, but again that shouldn't affect the spark strength.

How does the ignition module work?
I assumed it was more of a electronic gate keeper than a modifier of ignition current.
So I, like you, don't understand how it solved the problem, but it is running per the OP!

[FestYboy]

yeah, the IM gets a pick up signal from some sensor (depends on make/model) and when it sees that signal, it's supposed to RELEASE the ground to the coil causing the primary field to collapse. conversly, if the ground is bad within the IM it could cause a low energy field within the primary coil and then a weak spark, but usually that goes along with an intermitant spark as well.

[Pu241]

OK, so how does it "release the ground", in many electronic switches they have a mechanism which "de-bounces" it, keeping it from "bouncing" from one state to another multiple times when a single transition is required. If the IM has last this function, if indeed it ever had it, then the ground will be made and broken repeatedly over a longer period of time resulting in a spark but a weak one. If it was just a poor ground through the IM module then, perhaps if we ask nicely, the OP would re-install the old IM and see if it now functions. Corrosion is not a stranger to our vehicles so I can see that may well be the cause of the IM "failure".

[kartracer46]

yeah, the IM gets a pick up signal from some sensor (depends on make/model) and when it sees that signal, it's supposed to RELEASE the ground to the coil causing the primary field to collapse. conversly, if the ground is bad within the IM it could cause a low energy field within the primary coil and then a weak spark, but usually that goes along with an intermitant spark as well.

Wasn't sure exactly how it worked, I just had a 92 that was doing the same thing. I replaced the module and the issue disappeared. Never really understood why and how. Just thrilled it ran good again.

[Pu241]

Wasn't sure exactly how it worked, I just had a 92 that was doing the same thing. I replaced the module and the issue disappeared.

Any chance you still have the old "bad" module to swap back in to see if it was the module or a bad ground/corrosion at the module interface?

[Biff]

Scrap and clean the ground termination on the fender behind the relays.

[kartracer46]

Any chance you still have the old "bad" module to swap back in to see if it was the module or a bad ground/corrosion at the module interface?

Yes I still have it, I can look at it tomorrow and try it on another running car i have here to see.

[Pu241]

Yes I still have it, I can look at it tomorrow and try it on another running car i have here to see.

Thanks, I just like make sure we have the real cause of the failure!
Otherwise, we are wasting out IM for a corrosion issue.

[nitrofarm]

Thanks, I just like make sure we have the real cause of the failure!
Otherwise, we are wasting out IM for a corrosion issue.

Yes I would def like to know these results as well. Cuz as Festboy so well explained the IM is nothing more than a "Electronic Points". Instead of loosing ground via a mechanical device. The ground is lost through the spark output signal (spout) from the ECA to the IM. So I guess the question for the electronic Guru is... Can the IM have high internall resistance when its reaching its life's end? If the answer is NO. Then the culprit is going to be a dirty "external" connection in the ground path thats causing a weak spark right? But I'm guessing as the IM gets broken down from heat cycles its going to have higher internal resistance.I've always wondered why you cant run a real "HOT" coil with EFI. But I've never taken the time to think about it. But now I see if you have a coil with a Large primary winding. Its gonna flow more amps than the stock IM can handle. And the result will be a smoked IM. But all my rambling is speculative derived from a caffeine induced state. So I'll shut up before someone slaps me.

[FestYboy]

Nitro, you're correct in thinking that the "hot" coil will draw more amps across the primary winding. the thing is, the IM will only get hot if itself becomes a load within the circuit, so if the IM is in good working odrer, you should have no issue running that 'hot' coil.