N
Nazgul
Guest
Hello everyone,
In a 1985 L98 engine........when you initially turn the key for one click.....the fuel pump operates to charge the fuel rails and shuts off......Then I understand when you start the car, once the ecm sees 4psi from the oil pressure switch, the fuel pump is again brought online to begin fuel delievery. My question is this.....is the initial pressurization of the fuel rail is accomplished WITHOUT the fuel pump relay, as a check of the fuel pump operation, and after the car sees 4psi from the oil pressure sending switch it is at that time the fuel pump is activated with the relay to verify the relay operation. If the relay fails, at that time the ecm initiates the "Limp Mode" of operation. Is this correct reasoning? I have found a fuel pump low voltage code 54 and I am trying to reason all this out. My scanner never shows a rich condition, always a lean flag, and the car sputters and pops with increasingly more vigor the more you put your foot in it. I can initiate a check engine light if I really put my foot in it. Could anyone please comment on this condition? Thanks in advance for any help anyone can provide.
Geoff
In a 1985 L98 engine........when you initially turn the key for one click.....the fuel pump operates to charge the fuel rails and shuts off......Then I understand when you start the car, once the ecm sees 4psi from the oil pressure switch, the fuel pump is again brought online to begin fuel delievery. My question is this.....is the initial pressurization of the fuel rail is accomplished WITHOUT the fuel pump relay, as a check of the fuel pump operation, and after the car sees 4psi from the oil pressure sending switch it is at that time the fuel pump is activated with the relay to verify the relay operation. If the relay fails, at that time the ecm initiates the "Limp Mode" of operation. Is this correct reasoning? I have found a fuel pump low voltage code 54 and I am trying to reason all this out. My scanner never shows a rich condition, always a lean flag, and the car sputters and pops with increasingly more vigor the more you put your foot in it. I can initiate a check engine light if I really put my foot in it. Could anyone please comment on this condition? Thanks in advance for any help anyone can provide.
Geoff
