At last. Think I've solved it. Car was left out over the last few days in wet and windy weather. Went out this morning to give it a go and it fired first time as usual. Seems like the problem was the relay next to the ecu. It was the lower of the two and the one on the right in the previous photo. I took both out and gave a thorough clean getting rid of the green verdigree deposit built up over 25 years. A nice cheap fix.

Going to try and future proof my car. Read up on how to ensure a good contact is maintained for the future and came up with the product called dielectric grease or silicone. Having researched, it claims to be able to clean and seal electrical contacts on all parts of the system in a car. Bought some on eBay and will spend time giving all contacts a coating. Keen to get the plug off the fuel pump and give it some attention as its in a very vulnerable place for damp and dirt.

Bought this to treat the damp electrics on my car. First place was to clean up and grease the fuel pump contacts which are located in an exposed area under the back. Loosened the pump from the clip and unplugged the contact. Very dirty and moist. Cleaned with contact spray and cotton bud then dried with hair drier finally smearing this into the plug.

Having reassembled the pump mechanism the next contacts were the relays next to the ecu. To complete the clean up I treated the ht lead between coil and distributor. Took the car for a test run and all seems well. Time will tell, just need a few of those miserable wet days we've been getting recently.

Edited 30 January, 201610 yr by c.w.pritchard

Well. This was a simple and cheap fix. The plug in the fuel pump was the issue all along. This tube of silicone grease has made all the difference. Car is running as smooth as ever. A tube and paint brush and half an hour has converted a hesitant old car into a very driveable machine. Would recommend anyone with an older car to clean up and treat those critical electrical contact places.