Author Topic: fuel line check valve - whats its real purpose?  (Read 2961 times)

October 28, 2008, 12:23:52 pm

derekp

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fuel line check valve - whats its real purpose?
« on: October 28, 2008, 12:23:52 pm »
In my 92 eco jetta there was a check valve back near the water separator. Its a small black plastic bodied thing. It also happened to be the major reason why I pulled 5 inches of vacuum at idle.

Its not in the car at the moment - I'm having trouble finding a new one.

But I'd really like to know its full purpose.
Is it:
1. a federal safety standard thing (car rolls over, fuel doesnt come out all over)
or
2. to prevent drainback to water separator when car is shut off?

Can anyone provide some info on this nasty little culprit?
also any leads on where to get one.
VOA claims "out of country back order" yet they also cant find it in their picture book of parts.

thanks !


The fleet
92 eco diesel (my driver turned project)
94 suburban (mine)
69 Chevelle 327 w/hillborn - resting nicely
89 Jetta coupe (sons 16v ABA head swap w/turbo and megasquirt - not run yet)
2000 jetta (other sons)
98 jetta (daughters)
2001 jetta tdi (girlfriends)
03 subaru outback (girlfrie

Reply #1October 28, 2008, 01:39:30 pm

Quantum TD

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fuel line check valve - whats its real purpose?
« Reply #1 on: October 28, 2008, 01:39:30 pm »
It's option #2. I'm sure you could live without it. It just makes starting easier when the pump starts sucking air due to bad seals. The Rabbits never had them, so I'm sure you could live without it.

If you decide to live without it, and your pump is tired, you may have to crank more in the morning to get her started.

Reply #2October 28, 2008, 01:42:05 pm

the caveman

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fuel line check valve - whats its real purpose?
« Reply #2 on: October 28, 2008, 01:42:05 pm »
We used to take them on cars that had hard starting s issues when it was very cold and we couldn't find any of the obvious problems. Had no effect as far as we could tell, except POSSIBLY slightly longer cranking when very hot.
" I'm a vegetarian,not because i love animals, it's because i hate plants"
1970 Type 3 fastback
1972 Renault 12
1971 Super Beetle 140 HP 159 ft lbs
1987 Fox
1989 TD Jetta
1990 Fox
1989 Fox
1998 TDI Jetta
1990 T3 German MIL Transporter 1.9 na Giles super pump
1997 Jetta GLX TDI

Reply #3October 29, 2008, 06:47:26 pm

andy2

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fuel line check valve - whats its real purpose?
« Reply #3 on: October 29, 2008, 06:47:26 pm »
I remove the supply check valve to get more fuel flow it sure helps with modded engines.My Jetta TDI and my dads passat no longer have them.
94 Golf TTDI-M
99.5 Jetta TDI
86 Samurai M-tdi AHU rockcrawler