1999 GMC Safari 99 GMC Safari fuel pump system.

HARRY2

MEMBER
1999 GMC SAFARI
6 CYL
4WD
AUTOMATIC
105,000 MILES

Preparing to change the fuel pump and noticed a box? Beside the fuel TANK that has one line running to the pump. I have an idea what this device is. I think it is the fuel pump pressure regulator. CORRECT? Is this attached to the return line? Is there some kind of a test I can do that will tell me if it is working? I checked the fuse and changed the pump relay. I hear no pump running noise nor is there any pressure when I took off lines to change the filter. I'm assuming the pump is bad and bought one. I don't want to change the pump if there could be another reason why it's not working. That device I described above concerns me. How would I know if it's the cause.
Any info would be appreciated, Thanks.
Harry2

4/29 Thanks. Is it your opinion that the problem is just the fuel pump?

1 Reply

RACEFAN966

MECHANIC
5,029 POSTS

No it is not the regulator it, the regulator is under the upper plunem ontop of the fuel injection system. That is part of the smog system, the fuel vapor canister, this captures the vapors coming from the tank and then when it is triggered it allows the fumes to go back to the intake to be burned. Sorry you didn't get the answer quicker but I just saw the question myself. Anyway if there is anything more I can do let me know.