Hand primer sucking flat

[Dave]

I'd strongly advise against, it'll cause restriction if you don't power it... As you're seeing with the primer sucking down...

If you power it, it'll send the internal pump pressure insane.

If you must, fit the pump but ensure you use a pressure regulator set to a VERY low pressure, doing so really messes up the internal pressure of the pump, affecting injection timing and all sorts of other things... These pumps aren't designed for it, they're very finely balanced in terms of pressure on inlet and outlet - that's how the entire timing system of the pump operates!

If you do I can see a thread in <1 weeks time "my car clanks really loudly all the time and is slow as shit"...

Correction,

"my car clanks really loud and is slow as shit UNTIL 7,000RPM"