Hey Blazer community,

hoping for some help diagnosing an issue. My 94 s10 blazer has been running great until just a few minutes ago. I dropped my parents off at a hotel and helped them bring in their bags. When I came back out the truck had trouble starting. It finally started but idled super high. Without stepping on the pedal I got up to 25 mph. I made it back to my place but now it won’t start up again.

one additional odd thing is that it almost sounds like the brakes are pumping when I put my foot on the brake pedal to try and start it.

any idea what could be going on???

 

Not sure about the brakes, but how was the temp when you were at the hotel and leaving?

 

Temp seemed fine. Just a very quick trip to drop them off.

I was wrong about the brakes, it just seems like the electrical system is pulsating when I try to start the truck.

 

I asked about temps because if the engine is shut off hotter then regular temps, it'll high Rev upon restart if not cooled down.

How bad is the electrical? Have you checked for voltage drop on the battery?

Sorry I can't be too useful as I'm not really sure on the issue. But might get some answers for someone else who does, and comes across your thread.

All I know is two brainstorming is better then 1! Lol

 

Ground strap, Coil/ICM intermitted issue, Fuel pump intermitted or low voltage due to various electrical issues, etc. various things to look into. Start from the top

Suck Squeeze Bang Blow.
Probably have suck
Squeeze wouldnt cause it
So now we want to make sure its getting Fuel and Spark at the right time in the right cylinders, Pull the fuel pump relay, grab a spark checker, and check each wire while cranking for consistent, 1 inch of hot blue spark.
Put relay back in, check fuel pressure and leak down according to the pinned article.

Then we go from there. Failing anything, let it cool down again to ambient then try to start it, does it run right, Obvious gas smell (running rich)?
and as DonL said, check voltage drop. will give you a big clue to how the electrics overall are holding up.
Check Idle air valve or for dislodged vacuum hoses, PCV hose split, etc etc

so many variables.