Low fuel pressure, i think?

Hello fellow Mk1 heads.  Hopefully someone can help me before I start stripping my car to pieces and replacing things unnecessarily.

My gti idles lumpy, has poor mpg and the fuel pump (i think) is noisy and on continuously.   The fuel filter didn't squirt me in the face when I disconnected it  (as it has done on a previous Mk1).  Also when I undo the fuel filler cap there is no pressure release.  There are no apparent fuel leaks.  Would anyone off the top of you heads know these symptoms and the possible cause of the low fuel pressure and resulting poor running.  I really want to take it abroad to drive but need it running tip top.  

Cheers

Dein

If you can get an inline fuel pressure gauge it will help determine where your pump is knackered

Do you think its a pump problem?  Are these pressure gauges expensive?

Well, the fuel pump should be on all the time but is it noiser now right?

Poor idle, fuelling and noisy pump make it sound suspect.

It won't necessarily be low fuel pressure so much as erratic. If you pull a fuel line off and feed it into a jug when you turn the engine over is it a continuous high powered stream? If not you don't need a gauge to know it's broken (although no they aren't expensive)

Cheers mate,

Yes the pump is noisy, like an electric buzzing sound.  You say pull of the fuel line and put into a jug.  Can I do this at the fuel filter before the fuel distributor metering head or do I have to remove an injector.

Yep should be fine there, no need to pull injectors out you just want to check flow. Put it into a measuring jug if you can so you can give an idea of flow rate. Pumps are usually noisy when they fail

Thanks mate, ill give it go this weekend.