Cold start problem 1983 1.8 GTI. 5th injector?

Over the last few months my Golf 1.8 GTI has becoming harder to start when cold. It always used to fire on the button Last night it cranked for quite a while before firing so this morning I decided to do the following checks.
Engine cold, not run since last night, few pump relay bypassed, 5th injecotor removed, coil king lead earthed: Pump run for on minute engine not cranking no fuel dripping from injector.

As above but engine cranking: No fuel from 5th injector

If I put a voltmeter on the 5th injector wires and crank the engine I get about 9.5 volts for about 8 seconds (I wasn't really timing, I just wanted to check I had voltage and that it timed out).

I haven't done any cold pressure checks but as the car starts and runs fine once the initial cold start is complete I'm assuming that is ok.

I assume this is the 5th injector at fault although is 9.5 volts normal? I assume it is voltdrop because the car is craking etc.

Are 5th injectors available new?

Cheers, Matt.
 

Time for a bump I'd say!  

if there is a red./black wire on the 5th injector it gets its 12v feed from a spade near the fusebox, its tapped into the ignition switch.  if the wire is black, its fed from the 2nd spade on the starter motor.

the green/white wire is the earth, which goes to ground on the engien block via the 5th injector thermoswitch. check the wire has good continuity between the injector and thermoswitch for starters, and repeat your test with the thermoswitch unplugged and a wire stuffed into the green/white wire earthed to the coolant flange.

 if still nothing try earthing it to the battery to rule out an issue with the earth path thru the engine if you get me

Thanks for the bump Mike and thanks for the reply John.
I checked things through and come to the conclusion that the injector was faulty. I have fitted a 2nd hand replacement and it fires straight away from cold again now. It's strange how the cold start problem only started happening after I replaced the accumulator and I did wonder if the new accumulator was at fault!

Oh wow what great news my friend. ☺️
We all to often read nightmare posts on this subject so it's a real breath of fresh air to hear of a fairly simple fix! 😉 👍🏼

Sent from my Smartphone 📱