Dx. Odd running issues. Fuel related???

I have recently bought an 83 mk1 gti. The previous owner has spent a fortune rebuilding the car from a bare shell painting and powder coating everything.
the only negative about the car was he had painted it himself. I have just had it resprayed professionally and it looks amazing.

Anyway when I bought it the guy said it wouldn't idle well. He has replaced every part of the fuel system, tank pump and lines. The only part of the system that wasn't replaced was the accumulater.

I spent an hour today adjusting the ignition timing and co.
when hot the car would rev cleanly to red line but on idle it tends to be a touch rough.

After the car had been stood for an hour  I re started it but it spun over for a good few seconds before gradually starting and building up the revs.

The other thing of note is that the revs seems to fluctuate from one start to the next. One minute it idles too low at say 800 the next at 1200.

I reckon it's fuel pressure related anyone got any thoughts.?

I would like to test the fuel pressure to the metering head and the warm up regulator but I don't have a k jet testing kit.

I have always owned a few mk2s digifants and a few 16valves but any running probs with 16 valve has been confined to needing a good set up.

The other thing of note is that the rotor arm is an odd looking thing. It an odd shape with a spring in the centre. I think the spring is some sort of rev limiter. Looking at etka it looks like its the wrong rotor arm I think it should be a conventional one. Am I right?

yes thats a rev limiter arm, with k-jet 8v the limiter is either in the arm, or the fuel pump relay. if in doubt buy new bits:
AVS Car Parts - [The VW - Audi - Seat - Skoda Parts Specialist]

trouble with kjet is without fuel pressure kit you're just guessing! you can replace parts till eventually you find the problem or buy/make a kit. id look at wur from your symptoms, possibly its not quite right and so throwing control pressure out of spec

I ssuspect it is pressure related too. Where can i get a kit from or is anyone prepared lend one to me?
Not sure why but i suspect wur.

you could get yourself a gauge with 6bar pressure reading and a threaded pressure fitting, ideally with psi too as it makes wur tuning easier if you plan to do that. then take the WUR feed pipe off from the front of the meterign head and take it to your local hydralics specialist, and ask them to make up pipes that can go between the metering head and the wur pipe, with a tap to close of flow AFTER the gauge.

or make your own pipes, either way it'll probably be cheaper than buying a proper kit as they can be a bit spendy