*Posting a new thread on this, I've searched and searched. Found a few threads/responses that slightly touched on whats been going on with my blazer, but still felt the problem was genuine enough to create a new topic. Swartkk if I missed a thread.. feel free to chime in for me.

I own a 1995 4.3L Vortec, 4x4.. vin "W".. she's old faithful. Just turned 200,000 miles in June, and not a month afterward randomly, driving to work one day, the engine just stalled. I was traveling at 60-65mph, RPMs at/around 2,000 rpm. Normal. Just out of no where, she cut. Engine revved down, no response in the throttle, managed to turn the hazards on and pull over on the shoulder and shift to neutral. Only losing about 20-30mph when this happened, it cranked back up fine. Continued without any problem.

Then 3 weeks go by. It suddenly does this again. Same situation, same outcome.

The odd thing is, I had been driving with the MIL illuminated for months before this. I decided to do something, maybe to remedy this issue..I had them read, corrected the problems. I had an EGR valve issue. Also had a bad shift solenoid. The solenoid was a completely different and unrelated issued though. I did the research, bought the parts, did the work myself. Cleared all OBD codes.

Computer hasnt thrown a code at me since. Its been a couple of months at least. Here's the part that I'm competely lost about...

Just this last week it died again, same manner..this time twice in the same day..my gauges all read fine when it quit, SES light hasnt been on and did not proceed to illuminate following the stall. Furthermore not two or so days later, for thanksgiving, I drove 250 miles round trip in one day to see family...keeping a watchful eye... absolutely no issues. No codes. Smooth idle. No stalls. Everything nominal..

I have no idea how to even start to tackle correcting this random stall, especially with the computer not giving any codes.

Thanks in advance you guys.

TC

 

Check the connections in the ignition switch and in fact the switch itself. Not the tumbler that the key goes into, when you have it apart follow the rod down to the switch with the connector down the column. Sometimes you can have a loose wire, or just a failing switch.

Does it happen to happen going around turns or over larger bumps? I know stuff like this is hard to replicate but if there's a common factor it makes it easier to try and help diagnose. It definately sounds like an electrical connection somewhere losing contact.

Heres a thought, go out and start your truck in your driveway, then jiggle the key around and see if you can replicate it that way, then you don't have to rip the column apart right away.

 

Out of the handful of times its done this over the last several months only once did it happen after hitting a rather large bump going 40-45. That time in particular I pulled to stop in the emergency lane and for some reason it wouldnt fire. I had it in N and it was just turning the engine over. I let off it for 10 seconds, and it started right up.

I'll try jiggling my key while its running once this rain lets up.

 

could be fuel pump relay in the glove box... it sits at a weird angle

 

I only see two different relays in the glovebox. They both look the same, is this a universal part? Or would I need to go by a 'fuel pump relay'..

 

I'm not sure if the blazers have one, you can check with someone more knowledgeable than I about them. But alot of (in fact I think ALL new cars have them now) cars have an "inertia switch" that cuts the fuel in case of impact. It usually has a reset button on the side of it. Sometimes when they start to fail they cause these kinds of symptoms, but It's kind of rare.

 

No inertia switch.. I sat out in the driveway with the engine running, jiggled my keys in the ignition for about 30 seconds or so, it didn't die.

I've been doing a little digging. Found that the symptoms of a faulty Crankshaft Position Sensor match up very close to what I've experienced. Only thing is the CPS has 5 different OBD codes assigned to it, and I'm not getting any codes right now.

 

What about a faulty ign module, or coil..... (coil would be easy to test, ign module not so much). I had a bad coil on my motorcycle that when it would get too hot it would leak spark and not fire the plugs. then (even after a short period of time) would restart and be fine for a while.

 

Chevrolet Blazer 4x4 (Mid Size) 1995 blazer 4x4 4.3 vortec - JustAnswer Hi have the same truck same problem. Igniton switch fixed it. Hope this link works. Also if you have the starter switch out and would like to put in a remote start like a bulldog its sooo much more comfortable to due it on your kitchen table then under your dash. Good luck from Hamptonbays. PS. REALY BAD ON LEFT TURNS, TRUST ME!

 

Thanks for your input. Problem has not occurred now since couple of days before Thanksgiving. Im going to look into the coil and ignition switch. I need to learn how to do those types of tests anyway. Time to learn, woo!