Not sure but I believe coils can get hot and shut down. Try searching it. I can't, at work

 

Thanks for the input. I feel fairly certain it's not the coil, I'm still getting spark when it won't start. It will fire off of ether but dies once it burns it out. I'm not getting fuel.

 

Your problem sounds exactly like a bunch of bad coils I've encountered over the years.

Are you sure you're getting adequate spark? How are you checking that?

If you think it's fuel, carry a fuel pressure gauge and a volt meter with you on your next "test drive." When it dies, immediately test for fuel pressure and for voltage at the fuel pump.

Also, humor me, carry a can of "keyboard duster" with you. When it dies, turn the "keyboard duster" can upside down, and carefully squirt the liquid on the iggy coil to cool it off. Be careful, the liquid in those boils at a very low temperature, and if you get it on your skin, it will cause frostbite. If cooling the iggy coil makes it start, the coil is the problem.

 

Is a bad coil going to cause the fuel pump to not cut on when the key is turned? It is still sparking as it will fire on ether I'm not sure of the quality of spark though. But the fuel pump is definitely not cutting on

 

The fuel pump should cut on for a prime cycle a second or two after the key is turned on.

If that's not happening, check for voltage at the fuel pump relay. The coil on the relay should get voltage for a few seconds, starting a second or so after the key is turned on.

Will it start if you jumper the fuel pump relay with a fused jumper? You can also use the keyboard duster/cleaner trick on the fuel pump relay. If cooling the relay makes it run, the relay is bad.

Don't drive it with the relay jumpered. That relay is a safety device that shuts off the fuel pump when the engine stops. In the event of a bad collision, that prevents fires. If the relay socket is jumpered and you get into an accident that breaks a fuel line, the pump will continue running and pump all the gas in the tank out the leak, often resulting in a very bad fire. A friend of mine spent months in the hospital from this.

 

It starts and runs fine for 20-30 min then just cuts off no matter acceleration or deceleration. After that the fuel pump is not cutting on at all when you turn the key. I have swapped relays changed ignition control mods. I don't think the pump is bad because this happened before the new pump.

 

Starting fluid can fire without spark. So you haven't entirely convinced me that you have good spark. Check that by pulling a plug (#1 works well for this) and putting it on some grounded metal. Watch for an actual spark.

Debugging the fuel pump, first, when it's not starting, check for pressure with a gauge. If you have no pressure, start tracing down the electrical circuits. Jumper the relay with a fused jumper. If that gives you pressure, then you know the relay isn't cutting on. Check if the relay is getting voltage for a few seconds on the control input. Check ground on the relay coil.

You mention this is a "late 1995." Is yours OBD-II? Does it say "OBD-II certified" on the emissions label? Is the PCM on the coolant tank, and does it have the 12 wire spider injector?

 

I will try to check the spark. It's hard to work on it on the side of the road and mostly by the time I get it home it's fine again lol. The truck is obd1.5. The comp is under the hood and the the connector under the steering wheel but it is spider injected

 

Get a can or two of the "canned air" or "keyboard cleaner." It's only like five bux at Walmart or Office Staples. When it stops, turn the canned air/duster upside down and hose the coil down. You'll probably be able to drive home after that.

Your story (and your testing) reminds me of an incident I had with a race car thirty-odd years ago. The car would run for 4 or 5 laps and die. All through Friday and Saturday practice, I was chasing a (mechanical) fuel pump issue or "vapor lock" (not really likely at 40-140mph speeds, wide open throttle, but I was young and stupid back then). Everyone was telling me it was the coil. I "knew" the coil was good because it would fire up for a few seconds on starting fluid/ether. We qualified 3rd before it died during the qualifying session late on Saturday, and when the car came back on the tow strap, the driver who was on the pole was standing where the car stopped in the pits with a CO2 fire extinguisher. He hosed down the coil with the CO2 fire extinguisher, and he told my driver to start it up (it started right up) and get back to the paddock and tell his mechanic (me) to change the ignition coil. He had two spares if we needed one. He said he wanted to beat us fair and square, not because we dropped out with mechanical/electrical failure. His "spare" ignition coil (in our car) beat him to the finish line the next day.

 

im having identical issues i have a 2000 gmc jimmy after warm up its like its cutting fuel pump and stalls and wont fire up right away but wait a few mins and it fires up, im going to put a spare coil and i guess the other thing beside it with the aluminum fins, that i pulled out of a parts truck last week.