Expert: Skip Bollinger - 3/6/2007

Question
Hi, i have a 94 chevy s10 blazer 4.3 vortec v6, the problem i having is every morning i can start up my blazer fine but once running it seems to sputter when i step on the gas like it going to die out. after about 20 minutes of driving if i turn the blazer off and try to start it again it will crank but wont start  untill it has sat for atleast 5 hours then it will start right up and do the same thing over an over.

Answer
Charlie,
  If you look at my profile, I'm a Parts Specialist, not a Tech but I will offer my thoughts with 34 years on a parts counter.
  It sounds, to me, like the fuel pump is going out. How many Amps is the fuel pump drawing? It seems as though it is getting hot and has to cool from drawing too many amps. Have you run "fuel pump volume" and "fuel pump pressure" tests?
  This isn't the "old days" when you could pull the fuel line off the carburetor and have someone crank the engine and you see if the fuel "spit" over the fender. This is the day of Hi Tech vehicles and Hi Tech (read expensive) test equipment.
  Some of the symptoms act like debris (rust) in the tank but you wouldn't have to wait for 5 hours for the debris to fall off the sock.
  In closing, you didn't tell me where in the country you are. The pump is in the tank so if the ambient temperature is low, gas is cooling the pump. As the ambient temperature rises, so will the fail rate for the pump so you better look into it quickly before it leaves you, your wife or child stranded.
  This is the best I can come up with, being a Parts Specialist. Good luck..
Skip