Ignition woes - help please!

[custmfxwg]

I'm sorry. I'm a dope!! Totally forgot you already wrote that above... I even took note of it when I read it because that is the setup I have on mine.... Sorry

No worries I'm off to rig a gas can gas tank.

 

[custmfxwg]

Quick update - no change.

I remove the fuel cap and still had the same problem.

I rigged a gas can to the input of the fuel pump, vented the carb, check pressure at carb inlet (6 1/2 - 7 lbs) and still had the same problem.

I bypassed the ignition switch and ran the MSD switched lead (small red wire (on/off)) straight to the battery and still had the same problem.

Plugs are new and gapped at the stock recommendation of .035. I've read with the msd ignition the gap should be a bit larger. Would a small gap make this big of a difference? Can't see how this would matter because I had the same problem with the HEI and carter carb - just grasping at straws at this point

 

[JR74CJ5]

At this point I am lost my friend...

Have you checked all the grounds yet? If you could test the power to the distributor WHILE it is acting up, you could rule out or in electrical vs air fuel mixture...

Mentioned before, bad grounds... Unlikely, but have you checked them all?

Is there ANYTHING else we might not know, trivial or small anything to spark a thought?

Have you looked at the rockers with the valve covers off and its running? (sorry, long thread, can't remember...) will get messy by the way...

I would assume a vac leak would happen all the time not intermittent...

 

[bondo258]

Did you set HEI timing with vac adv. disconnected and plugged? afterward plug vac adv line directly to manifold vacuum. The Jeep dist works the other way I've read. It must be plugged in when setting base ignition timing.

don't use the cto in your test. the egr doesn't matter in this test, either. the five port isn't easy to troubleshoot. Mobody runs them with the (discontinued) filter, and this causes internal leakage, and not full actuation of the valve.

Aside from dedicated ground from Ign box to head, head to dist,(hose clamp to shaft) and ground to head, I'm not sure any more ground problems could exist.

Which alternator do you have? delco SI series may send out too much RF interference, for modern electronics. I've heard of it on another forum, but never seen it in practice.

 

[Jeepsrule]

I am new and learning, but I will throw this out there.

So the jeep starts, it idles as the engine begins to warm up/gets hotter then the engine dies (moving or not moving). The engine has plenty of fuel/ new plugs/ new carb/ new hoses/ hows the air filter?
( if you have the teamrush upgrade done shouldn't gap be bigger or doesn't even matter? an expert should answer). Your profile picture of the jeep looks good and clean. Can we assume the engine is clean so the grounding might not be an issue. How about post some zoom in pictures of your engine ( a picture is worth a thousand words) someone might see something to help resolve, you certainly have tried hard to resolve this issue.

 

[custmfxwg]

It's fixed!!! I think anyway.

Thanks for everyone's help in troubleshooting this nightmare.

It ended up being gelled gas in the carb bowl. Not sure how that happened. I had just rebuilt it not two - three weeks ago. Might be that the carb cleaner I used caused it, or maybe someone put something in my tank, or maybe I did have bad gas to start with.

I tried the gas can and gas cap trick this morning with no luck. I then went with .043 gapped plugs. It always kept pointing to fuel, but the fuel system all checked out.

I had an old 2100 laying around so I decided to throw it on - after swapping some of the new parts from the freshly rebuilt one. When I opened it up to remove the jets there was this clear silicone looking gell filling up 1/4 of the float bowl!

Anyway, I threw the new parts in the other carb, strapped it on, fired it up, and drove around the block with no problems! What a week this has been.

I'll take some pics of the gell stuff and I also want to open up the original carter carb and see if it has anything in it.

Thanks again guys - you've all been a great help.

This site rocks!!

Curt

 

[custmfxwg]

Here's a pick of the carb bowl. Kind of nasty. This was freshly rebuilt 2 - 3 weeks ago!



Thanks again for all the help. Hopefully it'll keep running like new!

 

[jeepboy45]

NO !!!!! Glad you got it fixed... I think we all assumed (as you did) that the carb was definitely NOT a problem.

No kidding...what a week!!

Glad you got it running

 

[Torxhead]

Glad you found the problem, It sounds like the source of the problem is in the gas tank. Time for a clean out and inspection.

 

[custmfxwg]

Yeah, who would have thought the carb would be messed up so soon. I pulled the original carb and didn't see anything like what was in the 2100, but I'll need to clean the tank anyway just to be safe.

Thanks again for all the help, everyone!