Vannin' Home Forums Chevy General Discussion Van keeps losing all power randomly?

so, this guy gave me a very lengthy, very detailed, and very convincing argument that the problem is vapor lock at the fuel pump due to sediment. I've been treating it as such, and the behavior has been as he predicted. So for now, I'm going to test the spark to make sure (been too busy to open it up), and if it's not that, i'll throw a filter in the fuel line and see if that fixes it.


not that anyone cares, but hey, there's the update. ;)

well, now it's just dead. goofing around and poking and half assing my investigation is over. Gotta actually fix it. womp womp.

Pull the rotor cap, under there is a black box. That is your coil. Very cheep, like $10. Pull it, get another & install it. You can even get one for a dollar at the yard. If it fixes it get a new one.

I guess that rules out the vapor lock cause so. Try what frske1 mentions above, I have heard of coils breaking down like this. As regards whether anyone cares, you'll find they're a very caring bunch on here. Intermittent faults can be a PITA to fix and even harder to diagnose when your not in front of the machine.

Prezz, it's a 78. I think it's the GM HEI, but didn't they run a conventional coil on top of the intake? Or not. Lol. I may be incorrect after looking at the link.
I was a Plumber in 1978, and you know what they say...

Nomad, Type of coil? If its dead, does it have spark, or 12 volts at the coil with the key on? Power to the Ignition switch? Fuse block? Starter solenoid?

Fusible link? You need a factory service manual and a wiring diagram, or better yet, a GVan electrical manual.

We totally feel your pain. You are Totally on the right track. Good job Nomad! Good Hunting!

Sry I just saw G20 w/ 350 ...

The HEI setup in the link has the coil under the cap. My 327 was from a 69 Impala. I do remember it did not have a points distributor. So I do believe IDK for sure.

The Truth is out there....

Lol. Cheers!

Thanks guys. I haven't had a chance to look at it yet with thanksgiving and all that. I'll dig into it tomorrow. Gonna start with checking for spark and fuel pump failure and go from there. Ain't got nothing else to do tomorrow so hopefully can get it going. Fun part is my motorcycle has a bad crank bearing too, so both of my vehicles are sad. unfortunately I have to head back to NYC for a project for all of December. May end up buying a newer FI DD truck when I get back and moving the van into part time fun vehicle/project status.

Appreciate the help. Btw, the "no one cares" comment was more about poking fun at myself for putting my vehicle woes on the internet.

Well, I finally did some actual testing but still no idea what's going on.

Turned van on and pumped the gas pedal with the air filter off, could see it pumping gas into the carb just fine.

Checked for spark... no spark at all. Starter still cranking happy, battery showing a perfect charge. No spark. Distributor is HEI already. Power wire to distributor sending power fine. Coil showing 12 volts with key on. Took distributor apart to make sure connections were ok inside. Couldn't see anything wrong. Plugged every thing back in and put the distributor back together and suddenly it fires up first turn of the key. No f**king clue. I hate electrical gremlins like no other. I'm going to go drive it around but my assumption at this point is that it's going to do it again. I have no idea.