[GARYB]

My 1991 12V is suffering from fuel pressure loss after shutting off. Verified this with a pressure test.
This makes for hard start unless I wait a while with switch on for a while before start.
My experience on other cars is it is likely the fuel is draining back thru the pump after turning off.
Does anyone know if the pump has a check valve and is it serviceable ? Or just get a new pump.
Thanks in advance.
Gary in Texas

 

[Alfisto Steve]

It has a check valve in the outlet fitting but finding a part number for just that fitting is hard to do. My Ferrari friend had one in a Bosch box but i didn't get the number from him - my bad.

Lots of choices on ebay that look the same or nearly the same as 164 check valve.

Unless your car has modified wirng just turning on key won't turn on the fuel pump.

I bought a 164 years ago where they had done that so pump would pressurize the sytems as check valve was bad in oultet fitting of pump. Not really best way to fix the problem though if you every had a fuel line rupture in an accident.

 

[GARYB]

Thanks Steve,
I'll start looking for an inline check valve.
Regards,
Gary in Texas

 

[ChazzyD]

...or the short hose that is connected to that check valve has a split in it, is more likely the case as check valves don't normally fail as they are very simple devices. That hose is a known common failure point. Mine had the same symptoms until I replaced it with Gates Submersible fuel hose. You only need less than 2 inches of it.
Charles

 

[GARYB]

Charles, thanks will check.

Steve, my car pumps with key in on position. Interesting ......

Regards, Gary in Texas

 

[GARYB]

Well finally got around to taking pump out. One major problem was there is a short length of hose, 4", that was the old fiber coated type. It was porous and added to my loss of static pressure. There was no check valve though.
Cleaned the screen and put it back together.
Starting is much better, but not as good as it could be. When I get time I'll do another pressure check and go from there (add CV). Have to get my **** hand operated on so maybe a couple of weeks.

Regards, Gary in Texas