83 cj7 with 304 swap. Help with ignition fire please

[smokedoff]

Hey guys. New here and need some help with an ignition issue. I bought this Jeep several years ago with a AMC 304 swap and it’s always ran great. Well, due to circumstances, it has sat for a couple years. Drug it out and got to tinkering and found an ignition issue.

It only has spark when starter is engaged. When the key is turned back, it looses spark and shuts off. Now it seems to have no spark at all and is slightly pulling the motor down while cranking. (Imagine timing being way off).

It has a box mounted to the fender well with some wiring tied into the distributor, coil, and firewall wiring. It’s hard to research bc I don’t know what was what from year to year and how this was pieces together.

Any help??

 

[mitchelllogic]

Maybe post a few photos of the box, how it's wired to the alternator, to the solinoid, how the coil is wired (to the distributor), if there is a data plate on any of the parts, connectors on the box? These things will help other identify what you have, where it came from, and maybe how the PO wired it.

Maybe start with a quick check of fuses and n your fuse block and look under the dash to see if you have any fused taps inline.

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[smokedoff]

Maybe post a few photos of the box, how it's wired to the alternator, to the solinoid, how the coil is wired (to the distributor), if there is a data plate on any of the parts, connectors on the box? These things will help other identify what you have, where it came from, and maybe how the PO wired it.

Maybe start with a quick check of fuses and n your fuse block and look under the dash to see if you have any fused taps inline.

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I have figured out that’s it’s a duraspark system. I have a new ignition box that will be here in a few minutes. I found that I have 12v to coil, both sides, and the ignition box is receiving 12v. I’m not sure how to test the 3 wires from the ignition box to the distributor, but I’m not getting anything there, when cranking or any time.

 

[mitchelllogic]

Okay. That's a start. Post photos though.

Do you have an alarm system to complicate the issue?

Any other aftermarket electrical?

I'm not familiar with a two coil setup so my help will be Limited . Sounds off to me. I've never seen that before.

Your sure it's two coils?

In the meanwhile make sure your ground wire at.your distributor hasn't snapped off and that you have continuity.

Next verify you have a resistor wire off your distributor or not.

If it was working before and now it's not working what changed?





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[mitchelllogic]

Last time I had a similar issue it proved to be a faulty coil.

Maybe pull your coils and meter them out and see if they are still in spec or not.

I'm assuming you have inspected wiring and change connections for obvious issues first and that your ground strap from frame to motor and motor mount to negative battery is intact?



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[Petescj]

I have figured out that’s it’s a duraspark system. I have a new ignition box that will be here in a few minutes. I found that I have 12v to coil, both sides, and the ignition box is receiving 12v. I’m not sure how to test the 3 wires from the ignition box to the distributor, but I’m not getting anything there, when cranking or any time.

90% of the time when that Duraspark box's goes it leaves a goo on your fender. Whatever they use on the backside of the box melts and dribbles down the fender.

 

[mriplaybass]

I know that you appear to have ordered some new parts, and many people like the MSD ignition, or the stock ignition, but when I had problems 5 years ago with the stock system, I just upgraded to an HEI. Simple 1 wire install (2 if you want to run a tachometer). I have never had an ignition issue in any kind of driving situation since. Pretty much a bullet proof mod. The whole set up cost me around $55.00. Just my 2¢

 

[Petescj]

I know that you appear to have ordered some new parts, and many people like the MSD ignition, or the stock ignition, but when I had problems 5 years ago with the stock system, I just upgraded to an HEI. Simple 1 wire install (2 if you want to run a tachometer). I have never had an ignition issue in any kind of driving situation since. Pretty much a bullet proof mod. The whole set up cost me around $55.00. Just my 2¢

That's where I'm at with the AMC 304 in my 79. I messed up and set the engine at TDC on the exhaust stroke but figured that out. In addition to what Bass dsai you can get rid of that box and all the extra wiring for a cleaner look. In my case I'm also grabbing a longer power steering belt because the bigger HEI cap interferes with my power steering reservoir.

 

[mriplaybass]

That's where I'm at with the AMC 304 in my 79. I messed up and set the engine at TDC on the exhaust stroke but figured that out. In addition to what Bass dsai you can get rid of that box and all the extra wiring for a cleaner look. In my case I'm also grabbing a longer power steering belt because the bigger HEI cap interferes with my power steering reservoir.

I had to do the same thing to clear the pump. It is also really close on the upper radiator hose, but not really a problem.

 

[mitchelllogic]

Good points by all:

Do you want to patch/fix what you have or upgrade for reliability/performance.

I am on an MSI Streetfire w high vibration coil, a big cap, and rotor change. (Before I knew about Team Rush or HEI).


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[smokedoff]

Good points by all:

Do you want to patch/fix what you have or upgrade for reliability/performance.

I am on an MSI Streetfire w high vibration coil, a big cap, and rotor change. (Before I knew about Team Rush or HEI).


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Thanks for the replies and ideas! I researched all of the hei stuff, and honestly, I lost interest when reading about swapping distributor gears and not having much room for the larger cap. Not that I can’t work with that, but it went from what seemed like a nobrainer to let me investigate what I currently have a little more.

I figured out I have the duraspark system. Had 12v at the coil, 12v to the ignition box, but nothing between box and distributor. So I put a $30 Napa box on and I fired right up. I had also just rebuilt the carb. Seems to run great. It hasnt been driven in a few years.

I cleaned up some wiring and need to order some parts. Front hubs, top, seat covers, those type things.

Thanks for the replies!

 

[Belizean]

Yea get it running and fix it up some and drive it some. Then decide if you are a Jeep person and decide what you want to do with it. Then if you really like it, dump some real money in it like the rest of us.