Man this is a terrible electrical situation !

[Thew]

This is me venting

My 82 CJ7 broke down a few weeks ago, the dizzy rotor just broke apart. after inspecting the dizzy I decided to replace it as it was very loose

while I was trying to figure out the problem it back fired and blew the muffler apart....

So now between the rain storms here in Oregon (watch the news!) I have replaced the muffler too.

So now it has been 3 weeks that I have not been able to drive my beloved jeep. I got it fixed and drove it to breakfast and it seem to run great.

when I went to start it it turned over but had no spark! and its pouring rain

had it towed home on a flat bed, when it was unloaded it started right up

today I started it and let it idle for awhile, the rain stopped for a few hours. It died after 15 minutes.. no spark again

so now I have to wait for the rain to stop so I can get an oscilloscope on the dizzy pick up to see whats going on. that's what I get for buying cheap parts.
Long live the AMC 258 i6 / 4.2l
sorry you read this far :rock:

 

[Cheepjeep85]

are we talking factory stuff here, because this could be a couple of different things causing this problem, coil breaking down, ignition control mod., stuff getting wet. there is a way to test the coil with an ohm meter, and your local parts store should be able to test the control mod.

 

[Thew]

are we talking factory stuff here, because this could be a couple of different things causing this problem, coil breaking down, ignition control mod., stuff getting wet. there is a way to test the coil with an ohm meter, and your local parts store should be able to test the control mod.

I live in a very small town, there are 3 auto parts stores and all 3 are full of idiots they couldn't test their way out of preschool

I have a full arsenal of electronic test equipment but the rain will kill most of it. Its all stock ignition system. (I know I need to teamrush it)
its been pouring rain here for weeks and as soon as it lets up I will be out under the hood.
I'm thinking either the new dizzy is bad or the coil broke down when the rotor went bad, when the rotor failed the metal contacts broke off and fell in to the pickup. The coil had no place to put its spark.......

 

[fzsk4p]

I live in a very small town, there are 3 auto parts stores and all 3 are full of idiots they couldn't test their way out of preschool

I have a full arsenal of electronic test equipment but the rain will kill most of it. Its all stock ignition system. (I know I need to teamrush it)
its been pouring rain here for weeks and as soon as it lets up I will be out under the hood.
I'm thinking either the new dizzy is bad or the coil broke down when the rotor went bad, when the rotor failed the metal contacts broke off and fell in to the pickup. The coil had no place to put its spark.......

That would do it.

 

[elwood blues]

The not wanting to start and dying after 15(ish) minutes is very typical symptoms of the ICM being bad. I agree whole heartedly with the rest of your diagnosis, just a little more food for thought

 

[Thew]

The not wanting to start and dying after 15(ish) minutes is very typical symptoms of the ICM being bad. I agree whole heartedly with the rest of your diagnosis, just a little more food for thought

Reliability is my highest priority so I will replace the ICM if I don't find any problem with this new dizzy and I feel the need for a new coil, its looking really nasty and old.

thanks for the extra input, now if it will stop pouring down rain so I can get to work

 

[83cj7]

Knowing that Oregon has no emissions, I'd switch it over to HEI and scrap the factory set up. Doable for about $100.00

 

[73CJ]

I'd switch it over to HEI and scrap the factory set up.

Ditto on the HEI. Instant starts. If you spend big bucks on stock parts. It's still a stock system. HEI is 1 wire hook up (to 12v) and very waterproof. A much hotter spark.

 

[Thew]

Thanks for the HEI suggestion, I'm going to stick with Ford parts because I already bought them and they are better Just kidding.

I want to go to the TeamRush setup soon but right now I just needed it to run again.

I put my oscilloscope on the dizzy and watched the signal.

This is how I hooked in to the dizzy.

this is what the dizzy pickup put out.

After about 15 minutes the signal went flatline, so I replaced the dizzy with another new one (this time a better quality one) and now it runs fine. As you can see the pick up is putting out a triangle wave at about 6 volt peak to peak. I checked the new dizzy and it generated the same signal but it did not quit when it got warmed up.
this is good info if you are having ignition malfunctions like I did

 

[CJ]

Did not read this this thread / I will / using a 97 is great! One of the best that Fluke ever produced. You seem to know how to use it!

 

[73CJ]

Nice scope!

 

[Thew]

Everyone needs a good scope

This thread started with me venting about having my Jeep towed to the inner workings of the Duraspark ignition system ! :grinjeep:

 

[CJ]

Duraspark = Bad.... More?

It is one of the hardest ignition systems to work on!

 

[Thew]

Duraspark = Bad.... More?

It is one of the hardest ignition systems to work on!

Hard? my only problem was the cheap parts I bought trying to same money then my own denial that the new parts were OK

I don't think Duraspark is hard just misunderstood