g741.org

Have you checked the compression? If you have wimpy compression, a slightly fouled plug(s), questionable ignition, and a goofy choke I can see a no start .

I have had issues with older military style plug wires. I've had 3 that were shorting to the braided jacket internally. They only did it under load. What proved to be the easiest test was as follows:
* Get a pencil and pull off the eraser and it's housing. Sharpen the tip, leave the other side blunt. It should be ~3" long.
* Pull the 1st plug wire and put the pencil tip up in the military plug. Put the spring of the wire onto the tip of the pencil.
* Get a helper to "start" the truck. While it's cranking you can lift the plug wire away from the pencil. If it won't jump 1/2" or more you have ignition issues.

If you have issues you'll have to sort if it's primary or secondary. Try each plug and see what you find, it will inform you search.

Andy

ps. Don't get zapped!

Thanks Andy, I'll give it a shot. I haven't tested compression yet because it ran just fine before I tried to install this pertronix. Just to be clear, the flat end of the pencil is grounded on the block, right?

Just drop the dull end of the pencil into the top of the military plug. Balance the spring at the end of plug wire on the pencils point. Lift and test spark.

Got it, thanks

I just tested the compression, and I'm getting....20-25psi on each cylinder??? How is that even possible? This truck ran fine a week ago. Do you guys think its worth trying a different compression tester?

I took out all the plugs and opened the throttle before testing.

Verify the compression tester with your compressor if you have one. If not try on another vehicle to see if it's in the ballpark. I sure hope your compression is not 20-25psi.

Turns out the first compression tester was a dud. A dud pertronix unit, and now this. Hasn't been easy! Anyways, my new tester gave me the following readings:

93, 87, 75, 90, 90, 80

This is on a cold engine with ~3-4' of compression tester line between the block and the gauge. I'm not sure what kind of adjustment needs to made to get a "true" psi...2pounds? 10 pounds?

Anyways, is this enough for it to even crank up?

is it a tester that screws in to the sparkplug hole those are the better ones

I used one that had a rubber end that just pushed in and I had low compression because it couldn't seal

It screws in to the block

I think shorten the hose and add hose clamps

and maybe spray some liquid in the depression around the tester (penetrating oil for example) ,so you can see if you are leaking any compression


and you may wonder why penetrating oil, because if it goes in to the engine it wont hurt it ,like say water

I got 'er running! When I was checking spark for the third time, I noticed faint additional discharges out of time. Turns out the old plug wires were going bad. I installed new wires and new plugs and she fired right up! This also fixed the problem I was having with the truck not wanting to idle without a little throttle and choke.

I was getting pretty close to loading it on a trailer and sending it to Charles. Huge relief to get it running again. Thanks again for all the input here.