help again with cold start issues mk1 gti 1984

losing the will to live with this I should just let it be but I wont let it beat me
bad cold starting problems ive opened a thread and looked and joined in on several post but still haven't solved the cold start problemso I will try again to see if someone in the know can help before I bin the complete system
Symptons
turn key to start car front stone cold it fires then dies in a second
turn key again with throttle it fires after 3 cranks and runs lumpy for a minute and then its perfectly fine
runs spot on drives really good with loads of power
starts from warm no problem

THINGS IVE CHECKED
Cold start valve operates for 5 to 10 secs on cranking when cold Aux air valves is open and closers as engine get warm Injectors spray evenly and don't drip and they have the same volumes timing is set spot on warm up regulater has been cleaned inside out new plugs ,leads ,coil, dizzycap, rotar arm



 

I'm almost sure it the WUR but if I understand its operation surely if broke/faulty it would always start from cold
it driving me mad
as far as I know and have read loads of info/books on its operation
The WUR controls the fuel pressure from cols engine to warm engine leaning off the fuel supply to the metering head as the engine gets warm
this is done by a biometric strip that heats up to push a pin inside the WUR when the engine is warming up the pin closers the port that supplies more fuel to the metering head and directs fuel back to the fuel tank
So if it wasn't working then its would be operating as if the engine was cold all the time so it would start from cold everytime !
please correct me if I'm wrong but this is how I understand it
ive spent hours on this engine don't get me wrong its driverble and with help from the accelerator pedel it starts from cold
but is not right it should start first time on its own rev to 1500rpm for a while and settle at 950rpm

only other thing is the thermos time switch I will check its operation tomorrow
if I don't set it a light and forget it ever existed    

If the cold start valve is doing it's thing for 5 to 10 seconds then the thermo time switch is working.

Saulty said

If the cold start valve is doing it's thing for 5 to 10 seconds then the thermo time switch is working.

thanks for that I can rule that out then
just leaves the WUR then
I need pressure gauges I guess anyone???

have you had the C/O checked?

regarding co/mixture
when started and warm up the mixture was adjusted to best running turning the screw too far results in strong rich smelling exhaust engine try to cut out
turn anti clockwise to lean off too much the car will try to stall so I'm quite sure its its in the right ball park ive set up a fair few engines over the years gtis g60s flat 4s ect..
but it wouldn't harm to nip to local garage get it on the machine then I know for sure
thanks for the help

I'm leaning towards a new set of injectors as although  ive tested the quantities and the spray pattern and results been good they tend to be a bit piddle when just open when fully open they spray very even
and if there not right when trying to start I reckon it could be hampering start up??

this is the little monkey in question hes trying me