My buddy's Jeep does the same thing, I told him to change the dizzy pickup coil first but has not done it just puts up with it. waits the 15-20 starts up and goes till the next time repeat the waiting game.

Another guy an old 80 or early 90's Jeep wagon the same thing I told him also change out the dizzy pickup coil as it's the cheapest or check it with an ohm meter also ign. coils can do this until they go dead but sold it as it did not want to put in any money.

A check the an ohm meter when it stops will confirm the low to no resistances.
But look up what the resistances is for your make & model for each the ign.coil, the dizzy pickup coil. and be checked fast after it stops. Theirs also a resistances check for the Duraspark box.


EDITED I see you our up against the wall being a jeep owner.

There is a list that goes on an on to many things to check or replace and it still fails fire up and keep running to find the problem.
Ign switch relay, position crank sensor, and the list goes on to loose plug on the ecm,.bad engine grounds. two screws in module top shorting it.

Hope you have some long spare time for testing learning how to test them.
But like everyone else says it's a electronic problem for sure.
Orich

 

I have pulled the air cleaner and pulled the throttle down, and gas is going into the carb. That's why I didn't think it was a filter issue.

 

Gentlemen, I REALLY appreciate all your thoughts and advice. I knew coming here was the right call.

Please keep the ideas coming, and I will let you know what I find.

Assuming it is the distributor and/or module, do any of you know if there is a particularly reliable replacement? Pertronix?

 

I'd check in to other aftermarket stuff if it were mine. Like MSD etc. Way back in the past I'd heard the prestolite stuff was junk. I had just chalked it up to opinions are like belly buttons. Everybody's got one. But after reading these posts I guess maybe that's correct. Well, it is a 1976 though. So since it is as old as it is, I see two choices to make it reliable. Throw replacement parts for the Prestolite system at it or a complete new system. How is the Dizzy's condition? Are it's bushings getting worn out? If the Dizzy is iffy that might make up your mind.

 

The engine was either rebuilt or replaced with a rebuilt engine in 2001 - there's a rebuild tag on it. The dizzy and module look newer than 15 years old - though I suppose the engine could have been rebuilt in 2001 and then sat on a shelf for a while.

Anyway, if I can get reliable ignition for under $100, that seems a pretty small price to pay. My research indicates that HEI units are a common upgrade. Any experience with the all-in-one units, where the coil is under the dizzy cap? Seems very simple, but also seems like a lot of stuff jammed into one thing.

 

I bet that would be a good upgrade. Pretty big cap on the HEI's but your 6 cylinder has all the room in the world. You'll also need new plug wires to fit it. Normal GM replacement parts should fit it in the future.

 

Clogged vent in fuel system? Dirt daubers? Non-vented cap?

 

OK, you know how sometimes your memory just doesn't match up to reality? Well, this is one of those cases. The dizzy, module, and coil are definitely not very new. I think the new-ish plug wires tricked my brain. So this is what I have:

Dizzy:



Coil:



Control Module:

 

Wow you need to clean all the corrosion & rust from all the wire end terminals, O better yet cut them out and replace them all. An or buy a new coil as it looks pretty old just for a starting place.
Orich

 

The later Duraspark distributor is a drop in replacement, and can be had fairly cheap. A DSII blue grommet module is under $50, and wiring diagrams are all over online (very easy). Huge upgrade in spark power and durability, and you'll be right around the $100 mark with parts that can be had from any parts store.

 

Yep. Decided to scrap all of it. Going with an HEI unit from CRT Performance - they were the only manufacturer I found that made one for under $200 that didn't have an unacceptable Chinese-junk-failure-rate. The others were all around 80% positive reviews and 20% junk. I don't have time for that. Hope I made a good choice. Will let y'all know. Thanks again for the help!

 

In that case I won't tell you to try removing that radio noise suppressor condenser off the coil.
Looks like you ought to order a valve cover gasket also.

 

No, please don't tell me that.

I am aware that there is a possibility I am throwing out a baby with the bathwater, but it seems like a risk worth taking in this case.

Yeah. I have it. Just haven't put it on yet.

 

The DS II conversion is more common on the Jeep inline six's. The HEI works well but you have to wire in a relay to make sure it's getting a full 12 volts. Also, make sure you get the correct drive gear or you can destroy your cam shaft. If I recall correctly, you need a distributor from an '80 Chevy 250 c.i. six cyl and the bronze drive gear for an AMC 304 V8. The fuel filter should be right in front of the carb, very easy to see.
I would post a pic of mine but I converted my 258 to EFI, in my '77 CJ5. Try posting on Jeepforum.com's CJ forum. The crew there is very knowledgeable and helpful.

 

did you check both your pumps and filters? almost sounds like the engine gets starved, maybe too much vacuum builds up after a while in the system moving the chunk of what-have-you to block. engine runs for a bit until it runs out of food. won't start up immediately because that pressure is still there, then after a bit lets off, the chunk settles back down. just my thoughts. It's also possible i'm dead wrong.