Fuel pump relay

Doing an engine conversion with a custom ecu etc.

Fuel pump relay keeps shutting off. Its a 7 pin one, Relay numbered 3.

I replaced this relay with just a normal one with only 4 pins and that solved it shutting off. So know that it is the standard part of the loom making it shut off. One of the 3 extra pins on the fuel pump relay to be specific. From the diagram it looks like these pins go into a transistor to shut the relay off. But what are these pins getting signal from?

Is it a crude rev limiter for the old engine? To cut the fuel when it got to a certain RPM? And now because it has no signal its confused? It was a GTI.

Any ideas?

k-jet relay need a rev counter signal to trigger them, so if the coil connections are dirty this could be why. if your rev counter works fine then its probably not this, it could just be the relay is shot!  a 4 pin relay isnt safe in a k-jet car as it wont cut out if you crash, unless you're runnign digi managment of some kind with a 67, 80 or 167 relay?