Now I've jumped the FPR with a fuse and a switch, and probably tomorrom I'll change the switch with a relay connected to something starting on the second step of the ignition key. And that's solving most of my sorrows; the car now starts and runs without any problems as long as I start the fuel-pump...

For me it's most likely that there's no tention to the connector no 15 on the FPR, and therefore the relay will not start the pump.

This might be the result of a broken OVP-relay. The ground should come from here, and the black/red cable goes through OVP to ground.
-If this seems like a logical conclusion please let me know, before I buy more useless spare parts....

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frogs
Mercedes 190E -86
Kawasaki Voyager 1300 -85

Fredrikstad, Norway
Heia FFK!