2000 chevy blazer, zr2. started having this problem yesterday and it's getting progressively worse. here's the skinny...starts fine, idles fine, then dead. Like sometime just told the engine to stop. somtimes it will idle and drive fine, then i'll be driving down the road and the RMP's will just drop for a second then come back up. sometimes they will flutter up and down and when i go to slow down the engine will just cut off again. not sure if its just coincidence but i was low on coolant and my temp gauge was reading low and bouncing a little so i added some coolant, its back up now. Last night my volt gauge was reading low and i just replaced the battery and alternator. Volt meter was reading fine today.

Things i've ruled out through properly checking-
-battery grounds
-FUEL PRESSURE
-spark
-distributor cap and rotor
-MAF sensor
I do have a slight vaccum leak in the blower selector (the one that changes from defrost to just floor etc etc) but i don't think it's enough to cause this problem.

I'm not throwing codes, and i really think this is a single faulty sensor but i don't know where to go from here

 

It sounds like a vacuum leak, hook up a vacuum gauge to it if it's around 17 in Hg then vacuum isn't the problem.

 

Mine did something similar to that and it was the ignition switch that was bad in it. may look at that as well it can make all kinds of strange things happen I found out.

 

i'm going to look into that tomorrow. i'm pretty sure i need one anyways since last year my blazer wouldn't start when it was really cold, i did alot of research on that being the culprit to that. maybe it just got real bad. that makes sense too because its like something telling my engine i just turned the key off..minus the hiccups i get while driving.