Good thinking, but ignition coil and ignition module are new, already been there! You're right, I put a new crank sensor on.Haven't started chasing after bad grounds.....cuz nobody wants to do that. No overheating either.


Yesterday I took the EGR off the "parts" truck (was a great yard truck, now I've stolen half the parts!). No change in performance, still driving along fine for a while then dies.


With everything new in the ignition system, what else could possibly cause loss of spark - and would that cause it to die right out? No sputter, shudder, nothing...


All other thoughts/suggestions appreciated!

 

the only other thing I could think of is bad engine timing,
but I feel like you would notice that

 

Yes, I think I'd notice it too, but since it idles smooth and runs well (up until it shuts off), I don't think that's it.


I'll have to start checking grounds, etc. Will let you know when I solve it!

 

thanks for the update.
I would spend most of your efforts on electrical elements, Sine that seems to be the problem.
maybe Ignition switch is losing connection?

 

Hey, TCG - thought you'd be interested in the outcome. After changing out almost all of the sensors, checking wiring, etc, I was getting nowhere. I started thinking that maybe when the wiring harness was damaged previously, it shorted something out. Found a wiring harness and computer for cheap, and limped the truck up to my buddy's garage to swap the parts.


Well, his son just bought himself a high-end scanner, so he wanted to try it out on my truck to see if he could find the problem. It came up as no signal from the MAP sensor (not MAF, like the simple scanner I have told me). The MAP is the one sensor I hadn't swapped out, so we robbed that off the parts truck, and now the S10 is working like a dream. Starts on the first turn of the key, no shutdown!


Thanks for taking the time to help!

 

I'm glad it worked out... troubleshooting anything electric is never fun

 

Hey guys,
How you all doing?
I pretty much have the same problem with my 1996 4.3 S10 Blazer but with no check engine light present.
It may shut off after an hour of use.
Or may go the whole week or so before shutting off.
(same as above)
Like if it was turn key no sputter, hesitation, jerking no warning what so ever.
All instrument cluster on radio on.
When it does shut off it may start right back up or may take a few hours before restarting or even a couple days.
I'm tired of throwing parts at it.
Any suggestions before I go on the WILD GROUND HUNT lol
Thanks in advance.

 

I know this may seem random, but have you left it parked next to a Ford for an extended amount of time? You'd be surprised how many Ford mechanical problems are contagious. (Surreptitiously Transmitted Diseases)

 

That's fantastic you were able to get it sorted out! And it's great we were all educated about the cause/solution for future reference.