Fuel Injectors not working

toatesarchitecture · Post by **toatesarchitecture** » 20 Dec 2024, 18:15

Hi - I've got a project car and there is an injector problem. When I test the injectors with 12v they all work, But when I crank the engine, they dont. Also even with new fuel relay, fuel pump only runs when I use jumper on relay power. Thoughts?

I checked all fuses.

Post by **jreed** » 21 Dec 2024, 06:09

When you turn the ignition key to the run position with the fuel pump relay installed, can you hear the fuel pump run for a couple of seconds or so and then shut off? If so, my understanding is that this is normal -- the fuel pump relay only allows the fuel pump to run for a couple of seconds if the ignition signal is missing.

toatesarchitecture · Post by **toatesarchitecture** » 21 Dec 2024, 08:02

fuel pump does not run at all with relay installed - new relay, but runs with jumper

Post by **jreed** » 21 Dec 2024, 09:18

I've got a '97 850 and haven't worked on V70's so I could be wrong, but I would suspect that the fuel pump relay is not good if the pump doesn't run/prime for a few seconds initially.
I'm not sure what would cause the injectors not to work, but I've read that a faulty camshaft position sensor is one potential cause to check. I replaced mine a few years ago and I was surprised how crumbly the original connector was... the plastic just fell apart when I unplugged it.

Post by **abscate** » 21 Dec 2024, 17:41

The fuel pump relay gets activated on key on, do you hear the pump whir for a second or two?

After starting, the relay has to receive a 40Hz? Signal ftom the engine to stay on.

If this car has never started you have to confirm the immobiliser is working, VIDA IS best for this