start up from cold

I have a slight issue with my 83 GTI tintop

on initial start up it revs to about 1000/1050 revs and idles ok, if you touch the throttle it is very lumpy/missing for about 15-20 secs then revs cleanly and idles ok albeit with a slight hunt to the tick over

so far I have checked all the electric connections and they seem ok
Had the 4 main injectors replaced
Fuel lines & injector lines blown through
tank has been emptied previously and flushed
new cam belt and timing set up
plugs, cap, leads, air filter are all new

I have today removed the 5th injector and set it up in a clear bottle and cranked the engine over, I got a conical fine spray from the injector and no leaks after it was shut off so am assuming this is all ok

couple of things I noticed on the 5th injector that there is no gasket where it mates to the inlet, should it have? source for an air leak?
the metering head where the injector lines bolt in, should they have copper washers either side of the banjo fitting? mine does not.

it seems I am very close to getting it running perfect but really want to get the start up sorted.

what do you think

cheers

Anyone got an idea? Could the hunting on tickover be accumulator

If it helps GSF tell me the 5th injector never fails. I'm not convinced, mine hates the first start of the day!

yes and yes to your seal/washer questions, have a red thru this thread ignoring the 16v specific parts, and when doing ign timing its set at idle with vac line on dizzy disconnected and plugged:
http://www.vwgolfmk2.co.uk/forum/viewtopic.php?f=37&t=25972

New 5th injector gasket and replaced all the washers on the metering head 
Then found the accumulator was leaking from the screw

New bosch accumulator and now have a steady idle and no starting problems

nice work