After <mumbles> time faffing on with the Nanocom flicking the fuel pump on/off on cold starts, I finally bothered my arse to swap the fuel pump relay for one of the screen heat relays.
Now it has only been a couple of days and this was always a bit intermittent but she has started first flick of the key ever since cold or warm. Coincidence?
Remember, you actually did two things:
First, you swapped the relay, and second and probably more importantly, you wiggled and jiggled (technical terms)
the fuseboard base.
Possibly just a mildly corroded socket, or perhaps a sign of a failing fuse box?
I've got a fusebox in my garage where the fuel pump relay didn't kick in when it should. That was down to a loose terminal in the fusebox so the ground signal from the engine ECU to operate the relay wasn't getting there. So Bolt's theory is right, if the terminal is loose, you've disturbed it by swapping the relay so it is now making contact, but won't do for long......
Although it might just have been a dodgy relay.
I did have a look see, and the terminals look good - but I guess they probably all do from the top.
The fun thing was I could hear a quiet clunk from under the bonnet when tell the fuel pump to run. Maybe the relay itself then? I could keep swapping to isolate the relay but... I'm not a massive fan of disturbing electrics on a P38 :)
Ah well, I'd rather not drop the tank just on the offchance so I'll keep an eye on this.
I think removing each relay and spraying the contacts with a contact cleaner (I use Nutrol which also has a contact lube in it) is a good idea on these. I think if this was done every 5 years or so the fuse/relay box might last much longer.
That does sound like a good plan...