Mk1 Golf GTi ... wont start, please help!

Please help if you can,

My Golf cab' (1800 8v GTi), is being a pain in the butt. It was stuttering ang stalling a few days ago, so we (Me and my Dad) thought that it might be a blockage in the fuel system,
(We'd replaced the, very rotten, fuel filler pipe a couple of months ago and knew that there was rust in the 'tank)
So we dropped the 'tank and cleaned that out thoroughly, cleaned the filters out as best we could, blew the 'lines etc...

But,

When we've put it all back together the engine wont start! or rather it will for a second or so and then dies.

We've checked the cold start injector and that's spraying fine,

However, there is NO spray from the injectors! Fuel is... just about getting to them, but not through them, it seems as though there's no pressure but when we crack the fitting from the fuel filter to the metering head there's LOTS of presure (fuel spray everywhere) There's just no fuel or very very little fuel coming out of the 4 oultlets on top of the metering unit.

We're at a loss as to what to do now so, if you can, please help

Thanks

illy