My 2000 blazer 4x4 will idle fine but goes to missing and won’t rev up high when you give it gas and will die after about 5 min of running and if you let it sit for about 5 min it will fire up again. I’ve rebuilt the motor with flat head pistons threw more sensors at it then I’d care to admit and have a new fuel pump and filter on it. I got a lot of money wrapped up in it and would like to get it running right looking for ideas.

 

I forgot to mention once it dies the starter doesn’t even turn over

 

I would start with why it wont crank after it fails because that may solve the other problem. You will need to travel with a voltmeter. When it wont crank measure the voltage into the crank fuse with the ignition switch in the crank position.


George

 

On the 'won't rev' part, I'm thinking that that could be the cat(s). If you remove the sensor before the cat, does it run any better?

 

I’ve been at this for a while so my first thoughts were the cats so I cut those suckers off it was much louder but still died and reved up poorly I’ve since welded them back on

 

I haven’t checked the voltage at the fuse yet I will check that as soon as I can really appreciate the tips I’ve been fighting this for over a year brought it to multiple mechanics and they’ve all said it’s this or that swapped it all out and no change

 

Last time I looked at the oem exhaust on rockauto I noticed there were two cats and I only cut the one towards the rear off so now the y’all got me thinking it might still be the cat I’ll check that as soon as I can thanks again

 

You hand me two simultaneous problems and I start with what can be common to both? In this case the ignition switch/start voltage/ignition voltage. Can these be two independent issues? Sure but it’s not the most likely possibility. The start thing has to be fixed no matter what or we can’t even diagnose the poor power development and that rabbit hole is impressively deep so we start here and hope that my late wife’s German interpretation of common American slang is true. “Maybe we can hit two birds in the head with the same rock”.


George

 

I took it to my local gm dealership to have their service department look at it. They told me it wasn’t the ignition switch but they couldn’t figure out how to take the bolts out of the plastic interior kick panel and just broke it off instead so I don’t really trust their word.

 

I apologize for the late response I work 30 hours a day 8 days a week so I never get a chance to mess with personal projects so after it died I was getting.03 volts at the terminal in the fuse box and it stayed at .03 when I turn the key to crank