91 940 Intank Fuel Pump powered?

mike: · Post by **mike:** » 02 Apr 2016, 15:55

Hey Guys,

I am in need of a document for when the in tank fuel pump receives power. The previous owner of the vehicle did an engine swap and bastardized the entire wire harness of the vehicle, there are no volvo relays of any kind at the moment.

I traced the wires for the in tank pump into the spare tire location where they abruptly stop. I've always only been able to drive on about 7 gallons of fuel until starvation and I would like to resolve this issue. I will also be wiring the fuel float sensor so that I can have a working fuel gauge in the dash.

Is the in tank fuel pump always powered on and if not what sends the signal, without using a stock volvo ecu, cpm or any other sensor or relay?

Thanks

lummert · Post by **lummert** » 02 Apr 2016, 16:30

What Model 1991 940? 940 SE? 940 Turbo? 940 N/A? Sounds like someone has deleted the in-tank fuel pump.

mike: · Post by **mike:** » 02 Apr 2016, 19:48

Hey lummert,

Thanks for the reply and it is a 1991 volvo 940 gle. The previous owner deleted the in-tank fuel pump, possibly intentionally, but based off of the other shoddy wiring and shortcuts, I would presume it was most likely an oversight. The in-line fuel pump can not pull more than half of the tank so I am carrying around a few extra gallons of gas.

I have 4 wires coming out of the fuel tank, red, gray, black, brown that are cut and end in the spare tire well. I can assume that power = red, ground = black, gray and brown are both fuel level wires?

Short of having the stock fuel relays, computers and stock wiring, I want to hardwire the in-tank pump (new carter) in series with the primary in-line (new delphi) fuel pump but I need to know if the in-tank is only hot at all times or if it gets a signal from something I don't currently have.

lummert · Post by **lummert** » 02 Apr 2016, 20:03

Put the in-tank pump back in. As the weather get's warmer the engine will stall with only 5 gallons gone from a full tank. Find parts needed at self service junk yard. Low pressure in-tank pump from a Chevy S-10 with TBI can be made to fit the stock sending unit without much fuss.

mike: · Post by **mike:** » 02 Apr 2016, 20:20

Sorry if I was not clear, the in-tank pump is brand new and is currently installed in the tank, it just isn't wired. The previous owner left a pump in there and cut the wires to it. I replaced both fuel pumps and the fuel filter.

I just need to know how/when the in-tank receives a signal to be on. I'm going to wire the in-tank pump to be on when the in-line is on and go from there.

lummert · Post by **lummert** » 02 Apr 2016, 21:12

There should be a fuse on the fuse panel for the intank pump. Finding a wiring diagram for your car would be a big help. www.volvowiringdiagrams.com

mike: · Post by **mike:** » 03 Apr 2016, 13:18

I've gone through all of the pdf's, I simply need to know of the 4 wires, what wires are what for a 1991 volvo 940 gle in-tank fuel pump and fuel level sender........

lummert · Post by **lummert** » 03 Apr 2016, 18:38

In-tank pump wires:
Pink from fuse #11
Brown or Black to chassis ground

Fuel sensor:
Green-White
Brown