dribble at fuel rail

tommylg · Post by **tommylg** » 18 Dec 2021, 18:01

I had no fuel pressure - just an ocassional dribble at the fuel rail schrader valve. The hard line is intact.
I have installed a fresh Volvo fuel pump - it hums, tested and tried four relays - all work, I am replacing the fuel filter today.
If the filter is not the issue, where do I go from here?
Kinda frustrating and I appreciate all replies,
Tommy

A couple of thoughts, here.
With the ignition on and the fuel pump hums, if I disconnect the hose fro the front of the fuel filter I should get a steady stream of fuel - correct?
If I get follow the fuel line to the hard line at the fuel rail and disconnect that - I should have a stream of fuel - correct?
How do I test the fuel damper on the rail?

Trying to be very methodical to track this down.

Thanks and good day,
Tommy

Post by **wizechatmgr** » 18 Dec 2021, 18:30

Sounds like the hard line is crushed somewhere...

Post by **erikv11** » 18 Dec 2021, 18:33

tommylg wrote: ↑18 Dec 2021, 18:01 I had no fuel pressure - just an ocassional dribble at the fuel rail schrader valve. The hard line is intact.
I have installed a fresh Volvo fuel pump - it hums, tested and tried four relays - all work, I am replacing the fuel filter today.
If the filter is not the issue, where do I go from here?
Kinda frustrating and I appreciate all replies,
Tommy

A couple of thoughts, here.
With the ignition on and the fuel pump hums, if I disconnect the hose fro the front of the fuel filter I should get a steady stream of fuel - correct?
If I get follow the fuel line to the hard line at the fuel rail and disconnect that - I should have a stream of fuel - correct?
How do I test the fuel damper on the rail?

Trying to be very methodical to track this down.

Thanks and good day,
Tommy

Yes and yes.

wizechatmgr had a good idea, too.

850oldschool · Post by **850oldschool** » 19 Dec 2021, 12:52

If you own one of these cars you need to also own or have access to a fuel pressure gauge. Whether you buy or build one, you'll need a right angle small Schrader connector like this:

https://www.langtools.com/search.php?search_query=74853

Many auto parts stores have a fuel pressure test kit to rent or loan, but they never have the adapter referenced above, which usually costs about $12.

Post by **volvolugnut** » 19 Dec 2021, 13:52

If you already have a 0-100 PSI gauge with 1/8 NPT stem, you can connect the manifold stem to the gauge with a short length of rubber hose and two hose clamps. Be sure to remove the valve core from the manifold stem before attachment and drain the gauge after use.
I have actually left this gauge in place for several weeks while checking a rough idle.
volvolugnut