Volvo Repair: fuel pump for 91 volvo 940 turbo, jet tronic, volvo 940

Question
I recently put an external & internal pump and filter on my car. I'm still having problems with
the car not getting fuel. I have changed the external pump a second time thinking I got a bad pump. The car runs for a little while then dies and you cannot give it any gas. My question is do I need to buy only Bosch parts for this Volvo since the after market parts dont seem like they
have fixed it? How do I know if I have a jet tronic or a motronic fuel system?  Is there any thing else that would make the car seem like the
fuel pump does not run?

Answer
it could be a bad relay for the fuel pump.it is jet tronic.some aftermarket fuel pumps are not very good and I have had bad ones from new.you would need to check for power to the pumps and check fuel pressure with a guage to see if it is a pump or relay problem.