I would like to know if my fuel system is leaking internally. I have my fuel pressure gauge hooked up between the fuel filter and fuel rail. When I turn the key to pressurize the system my fuel pressure goes up to 40psi then, without starting the car, the pressure goes down to zero within 5 seconds or so. I was thinking shouldn't the FPR hold a certain amount of fuel in there? I put in a new set of RC injectors so I know it's not the injectors. I'm using an SX FPR and a Walbro intank pump. Please help.

Thanks.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Islander &raquo;</TD></TR><TR><TD CLASS="quote">I would like to know if my fuel system is leaking internally. I have my fuel pressure gauge hooked up between the fuel filter and fuel rail. When I turn the key to pressurize the system my fuel pressure goes up to 40psi then, without starting the car, the pressure goes down to zero within 5 seconds or so. I was thinking shouldn't the FPR hold a certain amount of fuel in there? I put in a new set of RC injectors so I know it's not the injectors. I'm using an SX FPR and a Walbro intank pump. Please help.

Thanks.</TD></TR></TABLE>
Do Walbro intank pumps have a check valve to keep the presure from bleeding back into the tank like a stock pump does?

 

I'm not sure, but I didn't see any kind of valve... ...I'm not curtain if it has one mounted internally. The check valve you are referring to is usually mounted in the pump itself? If that's the case what can be done to correct this? Also, could this cause any problems?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Islander &raquo;</TD></TR><TR><TD CLASS="quote">I'm not sure, but I didn't see any kind of valve... ...I'm not curtain if it has one mounted internally. The check valve you are referring to is usually mounted in the pump itself? If that's the case what can be done to correct this? Also, could this cause any problems?</TD></TR></TABLE>
It doesn't really cause a problem, just a little extra cranking time for the presure to build up.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Islander &raquo;</TD></TR><TR><TD CLASS="quote">... The check valve you are referring to is usually mounted in the pump itself? ...</TD></TR></TABLE>
What kind of Walbro pump? (Not that I'd know the answer anyway...) Walbro makes a bunch of different pumps, for example Saabs used them starting in '89. Some had built-in check valves and some had check valves in the tubing (not in the pump itself). It sounds like you have one without a check valve.