Right, ok. I should mention now that this is in regards to a Jetta 2.0
in my Vanagon. A3 Bentley says to clamp the fuel return hose. If
pressure holds, regulator is at fault. If pressure drops, pump check
valve at fault. Unless I'm misreading, the A3 (Jetta) Bentley only
shows electrical checks for the fuel injectors. But yes. I understand
what you mean. Injector drip test is laid out in the Vanagon Bentley.

Some Jetta 2.0 engines have a nipple on the fuel rail (image):
http://www.jimellisvwparts.com/images/parts/VW/fullsize/128133300.jpg

for connecting a fuel pressure gauge. I have a spare fuel rail with
this feature so will clean and install when I pull the rail and
injectors. Seems to me this nipple would provide a means to isolate
the fuel rail-injectors and see if an injector(s) is leaking down,
injectors still installed.

On 3/2/14, Dennis Haynes <d23haynes57@hotmail.com> wrote:
> The injectors can be tested by removing them from the manifold and cycling
> the pump. If they drip they are leaking. The regulator can be checked by
> removing the return to the tank. If there is any flow with the pump off it
> is leaking by. The pump is a bit more challenging. On the CIS vehicles the
> pump check valve was often replaceable.  When those things vapor locked you
> better have a real good battery.
>
> Dennis
>

--
Neil n

Blog: tubaneil.blogspot.ca

'88 Westy http://tinyurl.com/c8rlw6p

'81 VanaJetta 2.0 "Jaco"  http://tubaneil.googlepages.com/

Vanagon VAG *Gas* inline-VR Engine Swap Group:

http://tinyurl.com/d7gd5ej