1999 v70xc fuel pump won’t come on with key

KiwiWandering · Post by **KiwiWandering** » 01 Dec 2022, 03:06

I bought this car with a blown head gasket. I just finished all the work and was trying to start the car and it wouldn’t start. When I turn the key I cannot hear the fuel pump come on. I checked the Schrader valve on the fuel rail and there is no pressure there. The fuel pump had just been replaced right before I bought the car and had been driven till the head gasket blew. I pulled the relay and put a jumper on pins 87 and 15. Still no fuel pump. Then I supplied power to pin 87(?) and the fuel pump came on. Fuel sprayed out of the Schrader valve. So the fuel pump is good.

My question is, did I forget to plug something in when I did the head gasket? What would cause the jumper wire to not work for making the fuel pump come on? Or is there something else? A fuse maybe?

Any help would be greatly appreciated.

Post by **abscate** » 01 Dec 2022, 04:32

Key has to be on , and jumper terminal 15 to 87 should work. With the relay in, It will only run for a second or two, then the pixies in the fuel pump relay turn it off.

KiwiWandering · Post by **KiwiWandering** » 01 Dec 2022, 08:05

Thanks for the reply. It wont come on with the jumper in and the key on.

Post by **abscate** » 02 Dec 2022, 10:12

KiwiWandering wrote: ↑01 Dec 2022, 08:05 Thanks for the reply. It wont come on with the jumper in and the key on.

Time to go back to the 12 volt connector under the plate in the boot and see if you are getting 12 volts there. I hope you aren’t , as the fuel pump job isn’t fun.

KiwiWandering · Post by **KiwiWandering** » 02 Dec 2022, 10:16

Solved! The computer modules weren’t seated properly! All good now.

Post by **scot850** » 03 Dec 2022, 15:14

Well that was a good find but a weird one! Well done!

Neil.

KiwiWandering · Post by **KiwiWandering** » 03 Dec 2022, 15:52

I can only blame myself on that one. I took them out when I was doing the head and just plopped them in afterwards without locking them down. Everything worked except the fuel pump in the key on position. Once I snug them down everything worked fine.