I have a 1994 s10 Blazer 4x4 with a 4.3 vortec automatic. ive replaced almost every sensor under the hood plus the spider and fuel pump. now it runs perfectly except after you drive it for a while it will lose power and backfire through the intake and sputter. you can floor it or just ease on the gas and it still wont get going and after you shut it off for like 10 minutes it will be fine again for a while. please help im at my whits end with this thing ive done nothing but throw parts at it and id like to see a good result. thanks in advance.

Tom

 

I,m having the exact same problem Tom, replaced everything, no results, looking forward to some expert advice.

Dillon

95 gmc jimmy 4x4 4.3 vortec

 

Have you hooked it up to a scanner to check the error codes?

 

yeah ive tried it all no codes. i talked to a mechanic and he said maybe something in the distributor but he didnt say what and i dont want to spend the money for a whole new distributor so i was hoping someone had a clue as to what could be wrong.


Tom

 

My 94s10 blazer did this same thing to I replaced everything , what ended up be wrong was the little wire harness going to the spider . It looked ok but it was bad now mine runs great. Everytime I would tear it apart it would work for awhile then did it again then the other day , it actully started quitting or almost stalling and I wiggled that wire and it ran fine 4 a little while then it finally just quit .

 

I had a similar problem with my Honda passport. I ended up changing my distributor, but one thing I would try first (off the top of my head) would be to hook up a fuel pressure gauge and see if you are getting the correct pressure to the fuel rail. When the truck starts to sputter you can see if the fuel pressure drops. I believe that the pressure should be up there in the 50's or higher? I don't have a tech manual in front of me but I know this forum has the info. But to me it sounds like your fuel pump might be crapping out on you.