Running issues.

[basssound]

I've got a 1990 gti 16v.
Lately it's been a pig to start, it spins over for ages before spluttering into life.
It then misfires under high load or high revs.
Now it's developed into not starting at all.
Came to it tonight, fired up then cut out instantly and then just turned over and over.
Checked the spark against the intake manifold using number 2 plug and the first spark is huge for it to Peter out to a tiny spark.
Had the plugs out cleaned and dried them, refitted them and eventually it spluttered into life.
Revved up ok, run on tick over and then petered out.
Again it was hard to start, run it home and left it for 30 minutes, went out and fired up first turn for it to cut out instantly, now it doesn't start.
Any ideas?

Possibly Hall sender?
Coil failing?

[sparkplug]

have you looked at your fuse panel ?
 mine had a melted fuse holder and so the fuel pump was intermittent

coils tend to break down when they get hot after running as the insulation fails
 
my hall sender when it  died ,  refused to start but was never intermittent one day good the next total failure
 

[Brighouse-gti]

Sounds like a fueling problem. I had something similar ages ago, for me it turned out to be the fuel pump under the body, well, ish ish. The wiring that went to the pump (under the body) had worn through and was causing an intermittent power feed. Fuel, no fuel, cut out, start again, not start, start, cut out!! Did me nut in and took some finding as I went down all the other routes first, turning the key and hearing the pump prime threw me off too, but got there in the end.

If that's not your exact problem, still sounds like a fueling issue!
Good luck!!

[gazareth]

If you had to dry the plugs then there must be fuel getting in. so it must be losing the spark.