Hei large cap issu

Hi guys, i need you're help on this one. On friday night we went for a night trail with friend when my engine quit me. We found there was no more fire coming from distributor. We have a good 12 volts on dist. Before engine quit i seen my voltmeter coming down to 11.9-12v as normaly it run around 13-14 volts within the power demand.

Distributor is a large cap hei on my amc 360.

So next morning i change the coil and ign module and jeep start again.

So on sunday we go back on trail without and issu. So we done little mud i needed the wash the jeep. When i finished washing the jeep i start the engine, it run about 4-5 second and quit again just like friday night. After 10 minutes playing with the wire it finaly start again.

The other weird thing is when engine stop making fire i was having little less than 12v on voltmeter just like a battery issus. But starter is going as normal, no sign of low power there.

So now i'm in a total confusion and i need advice to solve this problem.

Hope some have answer on this.

Thank'S

 

Need some background info.

Did you install this HEI and if so did you use original wiring or did you add wiring for the HEI.
How long has the HEI been in this engine.

 

Hum wiring is there since 4 year (po)
Po modified and Hei unit to put on engine. It becase loose, the hold down was crap. So i brought a billet hei built for an amc engine. I swapped about a year ago, never had an issu since.

I'm running a closed fuel tbi set-up (wont control timing ecm is using the tach signal using a tach filter).

 

The HEI loves a full 12.5 volt + minimum. Note that your ecm power signal and the tach signal both receive there voltage from the same source as the volt meter. I am wondering if the tach filter could be going bad...

 

Hum maybe it's aint a bad idea....but i remember try to crank it without the tack wire hooked to the dist and no change.

 

can you put a voltmeter on your alternator, while engine is running ...just to make sure your alt is putting out at least 13.5 volts ...battery will run the vehicle for a few days on the charge but will gradually degrade as it drains

 

I'm considering how this is all related. You said the voltage dropped, then the Jeep quit. This makes some sense with electronic ignition. But, you go on to say that you then changed the coil and ign. module and the Jeep started. Did your voltage also go back to 14.5 volts at this point? I wouldn't expect the new ignition parts to affect voltage output to your gauge. Is it possible your alternator is going out, and that this affecting your ignition? You also say that the Jeep refired after you played with the wire for ten minutes. Do you believe playing with the wire is what caused the Jeep to start? If so, I'd think that the terminal is loose or corroded; though I'm sure you've checked all that.

 

Given this a lot of thought and I believe this problem is with the ign switch or the wiring plugging into it. There is probably corrosion at the switch connection or the plug has shaken loose.

 

Hum i think i found the problem, not 100% sur but i found some water inside my fuel pump relay. Problem came back this week-end and i try another relay and started back again....hope is that...

 

Well I hope it is too. After market add-on's can cause a lot of confusing problems.