1991 740 turbo: Symptoms of in tank fuel pump failure? Topic is solved

Post by **June** » 18 Jan 2023, 11:16

How to tell if the in tank fuel pump is working properly? If it is faulty what are the symptoms? Thanks, June

Post by **abscate** » 19 Jan 2023, 00:03

Bad fuel delivery usually gives a no start, vs poor running. If fuel pressure isn’t right on, no running

Post by **June** » 19 Jan 2023, 00:11

abscate wrote: ↑19 Jan 2023, 00:03 Bad fuel delivery usually gives a no start, vs poor running. If fuel pressure isn’t right on, no running

This car has two electric fuel pumps. There is one under the driver's floor and one in the tank. I suspect the pump in the tank may be failing. Is there a way to test it? June

Post by **volvolugnut** » 19 Jan 2023, 08:27

If you have more issues when the tank level is low, that points to problem with the intank pump. For overall pump health, you can check fuel pressure at the fuel rail on the engine. Haynes manual says key on-engine off fuel system pressure should be 32 to 38 PSI FOR 240 VOLVO. 740 TURBO MAY BE DIFFERENT PRESSURE!
There are two fuel filters - the intank and external tank. You may have clogged filters. High miles /years since service may indicate full replacement of filters and pumps knowing how you like to maintain your cars.
volvolugnut