you're right about the botched immobiliser install, Neo!
had more problems, so i investigated a little further: the wire that had been spliced into the ignition was a bit of speaker wire that i traced back to the Fuel pump, where it had been wedged into the plug socket!
Decided enough was...
Many thanks for your help John and Neo.
I think i found the problem...
When i opened up the casing around the steering column, i found that at some point two wires had been joined as there was some loose black electrical tape around it - I reconnected them properly and secured them, and -so...
thanks John and Neo - I think i'll take the steering column casing off and have a little scope at everything and see if there are any obvious signs.
Neo: what exactly is the switch that you recommended i try out? i had a look on the GSF website, but I'm not sure what I'm looking for...
I had wondered about it being the ignition switch because sometimes, when i play about with the windscreen wipers, it starts - i had looked in my Haynes manual, but that says that i need to remove a sheer bolt, and drill into the chamber, so i didn't want to risk it: would i have to go to a VW...
My 1994 VW Golf has intermittent problems when starting - sometimes, it starts straight away with no evidence of problems at all (starter motor turns fine, engine kicks in after a couple seconds, and runs fine). Other times, i turn the key, and the starter motor just refuses to do anything. Here...