Really weird RENIX problem

[Nevada City Sparky]

Note from DJ
If you want to play the question and answer game again here we go.
In your original post you stated Quote: “New CPS (I tried 2)”
Questions:
Where are you purchasing new CPS at and why did you try two of them?
Did you replace now three CPS because of bad test results or just out of hope of repair?
When engine shutdown occurs is there any approximate time frame after start up this happens?
Example every time I drive my Jeep for one half hour while cruising along at 50MPH the engine shuts off.
What I’m looking for hear is there any type of pattern evolved to shut down that might indicate a thermal problem.
Last question for now what is the time frame between you’re engine shut down and your purging it which allows you to restart the engine?

I replaced at least 2 CPS's thinking that's where the problem was I read the Cruiser 54 "fix" and after getting a reading from the output, decided that wasn't it (was in spec).

There is really no pattern to when it shuts doen, except its always after it has warmed up and driven for a while. It is worse now that its warm, but I'm not convinced its heat related. what IS consistant is the restart. I can restart the vehicle 1 of two ways:
1. Jump the spark coil as described above to ground, reattach and restart.
2. Do nothing and wait 7 minutes. 98.5% of the time it will restart if I wait long enough and don't touch the key. If I try a start at 3 minutes, I have to wait another 7 for things to "clear"

My ‘88’s pattern was for about eight years was no start up hot or cold. I learned that if I looked at my tachometer and it was not bouncing while cranking it was time to raise the hood and unplug the and replug the CPS connector several times problem would be solved, I would also have engine shut down once in a while when costing to a stop same solution applied; but the only patter I had was it was going to happen sometime. In the meantime cruiser54 post information on how to increase the CPS output AC voltage. So after two engine shut downs on one short trip I declared the problem a safety hazard and the next day jacked up the Jeep and removed the CPS that I had ben professional replaced prior to my retirement and performed cruiser54 modification to the CPS and have had only one no start up since.

Hmmmm.... I haven't paid attention to the Tach during cranking.

 

[67 GMC]

I had a situation like yours. Would run fine and then once warm, it would die and be really hard to restart. Mine was a bad dipstick ground that would get un-grounded when hot. One day, while it was idling, I just happened to move some wires on the passenger side of the engine near the firewall and the Jeep died just like turning it off with a key. Re-did the grounds and haven't looked back. Use a wire-wheel to make sure you're down to bare metal before attaching wires.

I don't think it's TPS. MAP sensor tube leaking could cause a stall but usually it gasps a few times. If you pull the MAP tube while running, you can test that option. SOmetimes the tube gets enlarged or cracked and can get loose enough to stop the engine.