hi my name is paul, i have a 99 s70 it will not stay running. i replaced the fuel pump and fule filter. im getting about 40 psi at the shrader valve on the fuel rail with the koeo. but when started fuel pressure drops slowly down to 5 and stalls.
a. do you think its the fuel pressure regulator (its inline at rear of vehicle, and all the volvos ive called have never seen a bad one)
b. what is the electronic device that runs a hose from below the fuel rail and goes to the intake. could that cause this problem.

any one who could help i could really appreciate it. thanks.
-paul

 

can any one help me on this problem?????
any ideas at all?

 

A lot of times the fuel pump relay goes out in funny ways. You can take the relay apart and check the solder joints for cracks. If they're cracked, replace the relay.
It has been my experience that when fpr's go bad, they usually create hard to start problems, especially once the car is warmed up.
Can you hook me up with a picture of B.? I'm having trouble identifying it in the old noggin.

 

Paulie,

I bet "b." refers to the Idle Control Valve.

FWIW...I don't think the ICV will alter your fuel pressure...if that's what you're speaking of.

Seems I've read that loss of fuel pressure could be many things. Injector O rings leaking, faulty fuel pump, bad fuel pump gasket, fuel pressure regulator and probably other things that I can't recall. I wish I could help, but I'm just getting into these vehicles and have a lot to learn!!!

Good luck. Let us know what you change and how it affects the problem.


Ken