I've read through the fuel diagnosis charts twice now,,,,and am still stumped,,
I can start it up for anywhere from a couple of seconds to almost a minute,,
and i'm showing over 50 psi on the fuel pressure gauge...i was revving it up for a few seconds before it died this last time,,,,not showing any codes at all....as long as I spray gas in the throttle body..it stays running.....could somebody give me an idea if I should be changing my fuel pressure regulator or my injector???

 

when you check the fuel pressure you should have between 60-66 psi with the key turned on and the engine not running. If you have tryed it this way then 50 psi is not enough pressure. I would try replacing the fuel filter before throwing any big bucks at it, and see if anything changes.

 

put on a new fuel filter,,and now I'm showing 60 psi fuel pressure...it starts and dies immediately,, i can spray fuel in the throttle body....now I'm just trying to determine if it's the pressure regulator or the injector,,,I'm assuming the regulator is under the black housing sitting on the intake,,

 

May not be either one. Sounds like the security system, check out this tech article https://blazerforum.com/forum/showth...curity+relearn and try it.

 

I was driving down the road when it sputtered and died,,,would the security system have anything to do with that? I greatly appreciate the input..

 

yeah sounds like security to me. That's what mine would do when I had the ignition apart and I didn't have a certain metal piece in the right place.

 

I think I would replace the injector as it keep running when sprayed with fuel. If you hvae 60 psi, then the regulator is working, now that you have replaced the fuel filter....that was fun wasn't it!!....bet you love those plastic clips that the fuel lines go into...huh.

Anyways, if the fuel filter was that clogged..then some dirt probably has gotten to the injector and clogged it up. If you have the time, you could send it out for cleaning instead of replacing.

Just my early morning thoughts...

 

Security system wouldn't affect it while driving, I didn't know about that part. The classic symptom is "it tries to start then dies". This is because your fuel pump runs for 3 seconds when you turn the key on to prime the system. After that the PCM supplies power to the fuel pump relay when it senses engine rotation (and the security system is satisfied, etc.). Another possibility, a bad CKP (Crank position sensor) could do what you describe. If it doesn't know the engine is turning.............?

 

After finally diagnosing the blazer myself,,,I found that my fuel pressure would shoot up to 60 psi,,,but bleeds down very quick,,,therefore telling me that my fuelpump is bad,,,at least from what I can tell,,,that should be the culprit,,,the pump is only 2 months old,,,so it should be warranty.

 

You could have a bad FPR as well. The fuel pressure diagnosis link in my signature should help you narrow it down.