I had not started my 2004 Avalanche for about a month and now it won't start anymore. I've often gone this interval or longer without issue. I actually did get it to start and run for about a minute this morning, then it stalled out. I got it started again and it only ran for a few seconds and then stalled and could not be started. I checked fuel pressure at the test point on the fuel rail immediately after the fuel pump primes. Pressure gets to 40-45psi and then dwindles to about 30psi in about 30 seconds. Pressure continues to drop slowly thereafter. When trying to start the engine, the needle flutters between 50-55psi, but the engine will not start. Prior to all of the above, I had noticed the truck would occasionally stall about 10-15 minutes into a short trip. I could always restart it without issue and the problem would not typically recur thereafter.
Do the above conditions sound like a bad fuel pump? My pressure readings seem borderline, maybe passable, and I had changed the fuel pump about 6 years ago and swapped in an AC Delco pump, so it seems like it should have lasted longer. Are there any other checks I should do before replacing the fuel pump? I wanted to check to see if there is anything else I should test first since the fuel pump is a pain to change. Would bad (old) fuel give me the same problems?
Do the above conditions sound like a bad fuel pump? My pressure readings seem borderline, maybe passable, and I had changed the fuel pump about 6 years ago and swapped in an AC Delco pump, so it seems like it should have lasted longer. Are there any other checks I should do before replacing the fuel pump? I wanted to check to see if there is anything else I should test first since the fuel pump is a pain to change. Would bad (old) fuel give me the same problems?