[silverc4s]

Stijn asked:
is an mfi engine supposed to idle, even with this shut off circuit out of operation, i mean , is this system required for running , or is it a fuel saving 'feature' ?

Yes, it should idle as a purely mechanical system, even with the solenoid removed/diconnected.

I think that the switch/circuit is capable of completely shutting off fuel pump - perhaps it is shorting or broken?

It sounds like you are getting NO fuel at idle for some reason - perhaps initial settings on pump? Was the pump freshly overhauled?

A new engine is pretty tight, so it would need MORE energy to idle than a run-in equivalent one.

Wish that I could be more help, I assume you are using the CMA procedures..keep us up to date.

Good luck