92 s10 blazer with cpi, sometimes stalls. really it will always stall out but the time it takes to stall varies. originally thought to be a fuel pump problem because pressure would slowly drop. replaced fuel pump with same problem. i've connected the pressure gauge afterit stalls, and it reads zero. if you crank it, pressure will build to 60psi. if you rev it it drops toward 40psi the higher you rev. i'm not sure if this is normal. also the needle wobbles while running. it won't stall right away, it seems like its bogging down, then stalls. i'm not sure what happens to the pressure during this time. any ideas?

 

Mostlikely cause is a fuel leak internal to the intake. You can pull the upper plenum off relatively easily and inspect for drips...

 

yeah i was thinking that. i haven't had time to take the plenum off yet, tomorrow i'll look. i'm dreading it though since i put a new cpi in it just this summer. maybe just a line leak, but i don't think that would explain the intermittent nature of the problem. i'll post what i find if anything.

 

well i got into the plenum, didn't see any signs of washing at all. turned it to on position to build pressure, still no leaks. then i got the fuel pump out of the tank, turned it on, and it shot gas through the strainer. is this normal? now i'm thinking a regulator problem - maybe pump was faulty though?

 

I have an 94 blazer. I had a loss in fuel pressure which eventually caused me truck not to start. My fuel pressure regulator was leaking so I replaced it and thought all was well. Well it wasnt the problem. I replaced the fuel pump and reused the old pulsator, and it worked for about 3 days then the same problem. The problem was that the fuel pump pulsator was damaged as the Ethanol in the gas eats away at the rubber. Try replacing that with some fuel hose.

 

yeah i'm aware of the pulsator problem. i did replace the regulator and now all is well. i'm just happy it was something small and i am back on the road.

 

Happy to hear all is well

 

Any willing to help me find this pulsator, or give me a better descripition w/ pics as to what I need to replace. I've got this annoying random bucking and stumbling problem that comes and goes depending on if I look at the truck cross eyed or not