1998crewcab
OBS Enthusiast
when these trucks first start up they use the fuel pump prime
Through the ecm feeding the fuel pump relay for a couple of seconds
once computer sees the crank signal at a certain rpm , oil pressure switch will kick in and power the fuel pump .
you have to follow up and do the correct fuel pressure diagnostics 55-54 is minimal pressure to fire these trucks
Some one might help and show how to by pass fuel pump relay to power on the pump manually and try and start
Through the ecm feeding the fuel pump relay for a couple of seconds
once computer sees the crank signal at a certain rpm , oil pressure switch will kick in and power the fuel pump .
you have to follow up and do the correct fuel pressure diagnostics 55-54 is minimal pressure to fire these trucks
Some one might help and show how to by pass fuel pump relay to power on the pump manually and try and start