Hi all
I'm in a bit of a pickle!
My k75, 1987 was running a bit rough at idle especially when cold the fast idle in position one and two when cold it would hunt up  and down  not an even rpm as in the past. A bit of a miss at lower rpm but ran strong at 90kph and up!

Today would not start. No current to pump, pump bench tested fine. 

What colour wires are for the pump on the 4 wire connecter going to the tank.

Do the relays fail?

Cleaned the plug with detox.

Not sure what to do next, help appreciated.

The 4 pin connector under the left hand side of the tank is a known issue. You can try cleaning it and testing it. However mine continued to have the occasional problem so I ended up replacing it with a Duratec waterproof connector from a electronic outlet. Once replaced the problem was gone.
Regards Martin.

The 4 pin tank connector under the right battery cover can go bad.

GRN/WHT is fuel pump 12V.
BRN is ground.

WHT is low fuel lamp.
YEL is fuel gauge.