Flick RRMC
Registered Member
I have a 1991 suburban with battery,motor, trans and trans case out. Just to find out the tank is full. Is there a way to use the fuel pump to pump the gas out the line that used to go to the tbi?
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
To empty fuel tank
- Thread starter Flick RRMC
- Start date
Yep. Disconnect the tank sender plug that is along the frame rail very near the tank, figure out which wire is the sending unit wire, ground a 12V power supply to the frame, run the 12V + to the wire on the tank plug that was not for the fuel gauge.
I either disconnect the fuel line up towards the front where the hard line transitions to flexible, or at the fuel filter, and pump it into whatever receptacle you have.
I either disconnect the fuel line up towards the front where the hard line transitions to flexible, or at the fuel filter, and pump it into whatever receptacle you have.
Flick RRMC
Registered Member
Thanks will give it a shot
red wire on firewall @ the fuel pump relay is the test wire that sends power direct to pump .
Thank you, spaced that. It's the right way to externally power the pump.
Is there not a fuel pump test wire on the OBD1 connector? 
just what I posted is how gm did it on our trucks .Thank you, spaced that. It's the right way to externally power the pump.
Is there not a fuel pump test wire on the OBD1 connector?
There might be (would have to look at the pinout for the ALDL connector), I suppose if all you have to do is ground(?) a pin on the ALDL connector it would be easier than running 12V to the relay pigtail.
This is what I was thinking of. I haven't used GM's fuel pump pin, but with Ford's OBD1 connector, you supply 12V to the fuel pump pin to cause it to run.
As I recall, some GM vehicles used that pin, some did not. For some reason I want to think that truck TBI did not. All you have to do is look though, if there is a metal terminal in the cavity, odds are it does.
Hope that's directed at the OP and not at me...I don't have OBD or an ALDL connector. I don't even have any form of ECM!
Definitely OP, but referencing your pic of the ALDL connector. "If used" indicates it wasn't universal with OBD1 GM's.
