1999 S70. Fuel pump relay problems

[Gamecock843]

Hello my 99 s70 just died on me a week go, nothing mechanically wrong with the engine. I did th rundown, fuel,spark,air, compresion. Everything was there except fuel pressure so I went that route. Took the 103 red fuel pump controller out and jumped the 87 to 15 terminals, I hear fuel pump it cranks and runs great! I rip the jumper wire off and throw in a brand new 103 fuel controller in and it runs fine. But th car will not start and run unless I jump the fuel relay even though it's brand new.


Any ideas?
And one more easy question once I cut my car off and remove the key I can feel an electrical charge(not shocking) on the idle control sensor should it have a load even if the key is removed

[cn90]

Troubleshooting fuel system is below:

https://www.matthewsvolvosite.com/forums ... hp?t=52252

[Ozark Lee]

You could have a bad check valve in the fuel pump itself. A way to test that is to put a fuel pressure gauge on the fuel rail and see what happens to the fuel pressure after the key is turned off. If it quickly drops then the check valve is bad. The bad news is that the check valve is built into the fuel pump housing and the proper way to fix it is to replace the entire fuel pump assembly. Some have simply added an inline check valve on the fuel line around the fuel filter as a way to save shelling out for a new fuel pump assembly.

I'm not sure about the question about the idle control sensor. Don't you have a Electronic Throttle Module on your '99? On the throttle body versions it is normal for the idle air control valve to continue running for a while even after the car is turned off but I'm not sure what part you are asking about.

...Lee

[cn90]

1+,

If your car has more than 160K, then it is not a bad idea to get a new fuel pump.
Bosch 69693 for FWD model is about $85. Search for the posts by stephansvolvo.