1998 V70 AWD XC Fuel check valve

farmshop · Post by **farmshop** » 19 Jan 2014, 16:27

Why not run a 12v line through a momentary switch to run the pump before starting to fill the rail with enough fuel pressure?

Post by **jblackburn** » 19 Jan 2014, 22:41

Suppose you could...I think you'd have to hack into the fuel pump relay control on the front of the car, since the top of the fuel pump is inaccessible on the AWD models.

Most have found it easiest to splice a check valve into the fuel line rather than messing with the pump itself.

Post by **jimmy57** » 20 Jan 2014, 07:45

in hot weather the failure to hold fuel pressure when you shut down hot engine for a few minutes to fuel or run into store will result in vapor lock. Running the pump with the switch doesn't fix that. You still have to do prolonged cranking to get vapor bleed out via injectors.

farmshop · Post by **farmshop** » 20 Jan 2014, 10:54

Tried the check valve and it made no difference. There appears to be a 1 second timer that controls the pump at start up. If I could over ride that the pump should run until the PSI is up and the rail is full?