All 3 pumps were ac delco pumps and new wiring harness were also put on at the time of installation by certified technicians..The tank debris I have no idea, due to the fact that I never replaced the pumps myself...If a pump does not have enough pressure to start then how can it maintain high rpm for a prolonged period when running?
The shops just replaced the pumps and faulted the regulator for the problem with them burning out...but the last new pump was done with a new regulator and it only lasted a few weeks and the same ole situation... I talked to the technician and told him i was able to start the truck once primed so all he could say was possible leak in fuel lines causing a vapor lock or something. I inspected the lines for any fuel leaks and did not see anything, even with the pump pressured and the truck running. One note that my wife had noticed is when we picked up the truck from the last shop we went to start it and there was a little hesitation starting and then it fired right up.. She said that it did that with all the replacement pumps as well..She asked if they even fixed the problem, because it had never acted this way until the first time it died on her...Which was the 1st pump that was replaced a few months ago....
Hi Roy, I did a pressure test and ignition on fuel primes to 40lbs, but obviously will not start. I prime the intake manually and start the truck and pressure reads 54lbs while running at any rpm. Turn off ignition and fuel pressure jumps to 56lbs and then drops to 40lbs. The fuel pressure drops then from 40lbs to 30lbs in about 6 minutes.
No it only goes to 40.
ok, the pressure issue is the pump itself. is this one of the gm pumps??
All three pumps were AC Delco pumps
Hi Roy, I have removed the tank now and am going through everything and making sure to test voltage and checking all of my lines..I have a new pump but I don't want to put it in until I know everything is good. I tried to check voltage while it was in and it would just flash 10 to 12.3 volts while priming and would not hold a steady reading. I am going to try today to get an accurate reading with the tank out of my way.
ok, look for 12 volts or battery voltage.
make sure the ground is good otherwise you can have 12 volts and with a bad ground could drop the voltage low.