"ok here's what I got 97 gmc Yukon 5.7 I've replaced my fuel pump and new injectors have the problem its ,to high of pressure it's like 75 psi at idle drops when driving was told to check and see if return line was blocked so pinched it off and started it up at first jumped really high truck stumbled a little then pressure dropped to about 68 psi while running. Any suggestions or any body ran in to this problem any help would be appreciated "
WHEN TESTING<be sure the fuel pressure gauge reads correctly by comparing it to a second test gauge, these fuel pressure gauges are frequently defective
sounds like the return lines to the fuel tanks blocked , BUT ID check with a different test gauge because the stock pump usually maxes out at about 50psi, but if its not the gauge, Id try blowing high pressure air thru it after removing the tanks gas cap,
as a test as a start point, if its a clear return line back to the tank its probably a defective fuel pressure regulator
WHEN TESTING<be sure the fuel pressure gauge reads correctly by comparing it to a second test gauge, these fuel pressure gauges are frequently defective
sounds like the return lines to the fuel tanks blocked , BUT ID check with a different test gauge because the stock pump usually maxes out at about 50psi, but if its not the gauge, Id try blowing high pressure air thru it after removing the tanks gas cap,