Hey guys, I couldn't find anything for my issue and some direction on what to check would help.

I have a '95 Blazer LT 4.3.
Last week I was on a road trip from Grand Junction to Denver, heading up a mountain pass going about 60 when all of a sudden the engine just shut off. Was running perfect then dead. I coasted off the interstate and tried to restart. The starter would turn the engine but it just wouldn't start. Kept trying until the battery was dead.
When I got someone to pull over to help, we just put the jumper cables on and she fired right up. We were able to drive it the rest of the trip and started and ran just fine every time. Then on the way back from Denver, heading back up the mountain, same thing happened again, dead, ran the battery dead trying to start, jumped and started.
Its started and run perfect every time since.

I've had the battery, starter and charging system tested and they all check good. Newer cap and rotor, plugs are good.
Does not throw a code.

Not sure what to check next, anyone experienced this before? Any help is appreciated.

 

Intermittents are the most difficult of all.

Sounds like something electronic is getting overheated and your getting someone to jump start allows time to cool down. I had a bad ECM do this same type of thing on a brand new 1990 Pontiac - after replacing never again in 100,000+ miles. But saying your computer is bad would just be pure speculation. Catch it in the act... Does it have spark? Does it have fuel pressure? If not, then you need to figure out why before it starts working again.

Maybe fuel injector shorts out after a long time at high flow (going up mountain pass) - the computer is definitely programmed to shut down to protect itself electronically. An overcharging alternator (high voltage) can also cause the computer to shut down. Could be lots of things. Good luck! You might want to avoid running the battery down each time - save it for after things cool off.

 

First thing to do is check for codes. then do all the normal fuel system checks. Max Pump pressure and regulator pressure and leak down. sounds like a classic fuel pump issue to me.

 

I had a similar problem and finally was able to check for spark when it quit. No spark through the distributor cap that had been changed a month earlier, lots of spark to it. Replaced the cap and have had no problems since.