'83 gti cutting out, then restars fine

Hi all,

Ive not posted much on this forum before, i mianly come on for reference and can usually find the answer to most problems by searching the forum.

Im having a bit of trouble with my '83 gti. It starts fine in the morning, drives perfect, but every now and then, the engine completely cuts out, sometimes struggles a little bit before doing so, and other times just instantly dies. strange thing is, it starts fine almost straight away again, and runs fine, till the next time it happens of course.

The first time it happened there was a small bang/knock noise before it died. I thought a belt had gone, but checked under the bonnet and everything seemed fine, and as i say, it started straight up again and ran fine.

I've had the cambelt, fan belt, all filters changed last week, it had to be done at a garage as im really busy at the moment.

It has had fuel problems before, but ive had a new pump fitted, filler neck, and had the tank cleaned out, although not completely rust free, it seems to have solved any previous fuel problems. Leads and plugs have also been done last few months.

Apologies for the long post, but trying to give as much detail as i can.

Thanks in advance for any help, much appreciated.

Have you removed the plugs to see if all the ends are the same color ?

Yeah they all look fine to me, ive had the garage have a look and apparently its electrical.

The guy reckons it has something to do with the alarm. I had to have it ragged out to work on it, but it seems there is still a problem with it.

The cowboy who fitted it, not me by the way, has left a mess of wires and unprotected soldered wires under the dash. The alarm and said mess was present went i bought the car.

A mate reckons it might be an electrical fault causing the immobiliser to temporarily and randomly kick in causing the engine to cut out.

Thing is, i know nothing of alarms, and i thought the alarm had been removed. Is it possible that an immobiliser is still present and connected in a way that a fault would cause it to randomly "immobilise" the engine?