So i have a 88' 740 Turbo that sat for 6 years, trying to work through an issue right now where i'm not getting any fuel to my main pump. I haven't had the car long and in an effort to fix this issue, I've found a few others, and have replaced several parts of the fuel system.

Replaced:
Main fuel pump & Filter
In-tank Fuel Pump
Fuel Pump relay
Radio Suppression Relay
Fuel Injectors
Starter
Distributor

Fuses seem to be OK. When i disconnect the suction hose and have the main pump pull from a container of gas, it pulls, and the car will start for a few seconds.
When i use a test light on the fuel pump power connection in the trunk, i only get signal while the engine is turning over. Nothing while in the prime position. Thoughts?

 

It is my understanding that the LH2.2 fuel injection system (which is what your car should have) does not prime when the key is turned to the II position. So it sounds like it is working as it is supposed to. Pierce can probably verify this as he has had cars with the LH2.2 FI.

 

Is the fuel tank more then half full. If not put more fuel to get it to more then half full. When you replaced the in tank FP did you also replace the little rubber bellows type fuel hose. Also how was the screen filter at the inlet of the tank FP.

 

I'll try filling the tank up a bit more, I did replace the line going to the pump from the top of the tank, I also replaced the screen.

 

I think I'd get the car up on jackstands or ramps, disconnect the fuel line from the tank that goes iinto the filter/pump assembly, hook up a hose into a fuel jug, then manually jumper power the tank fuel pump and verify you get plenty of fuel squirting out. if you don't, something is wrong with the intank pump assembly you installed.

 

ITs very common that aftermarket fuel pump assemblies that come pre wired, are wired backwards. instead of pumping, your pump may be sucking.

 

So after filling the tank up nearly all the way, the engine started after a few cycles. First time driving the Volvo, super fun. But i had a water pump leak so i figured id replace it and tune up the timing system. Thanks for the help!

 

If this cured your problem then you need to replace the rubber hose inside the fuel tank. This is the hose from the in tank fuel pump to the top of the pump assembly.

 

.... and verify the pre-pump is pumping the right way and not wired backwards so its sucking.