At least you know how to wire it correctly. K-Jetronic is quite simple.

Speed sensing module? Are you talking about the black Bosch one that has "Drehzahlrelais" on it?

This could be the cause. The pink relay primes the pump when ignition is turned on and when the Drehzahlrelais gets a hall signal from the distributor it switches ground on to activate the fuel pump relay.