Airflow Performance fuel injection with purge valve

I have the Airflow Performance fuel injection (FM-200) with purge valve and was wondering about what fuel pressure I should see with the purge valve open (flowing). With the engine stopped, mixture full rich, and the electric fuel pump (Andair PX375-TC) on, I don't see a huge change when it's open or closed, about 34 PSI. Same on left and right tanks.

Does this seem reasonable?

I was kind of expecting that the fuel pressure would drop. I unfortunately didn't look at fuel flow numbers, but I'm guessing the reason the fuel pressure remains high is that even though the purge valve is open, the fuel flow through the FM-200 is still quite low.

Thanks for any insights!

rv8ch said:

....I'm guessing the reason the fuel pressure remains high is that even though the purge valve is open, the fuel flow through the FM-200 is still quite low.

Click to expand...

Works for me.

Thanks

DanH said:

Works for me.

Click to expand...

Thanks Dan.

purge valve

PilotjohnS said:

I think the purge valve is setup so that when it is open, there is not a lot of change in fuel pressure with just enough flow to purge. This way, if the valve fails open there will still be fuel pressure for the engine to run.

Click to expand...

When you open the valve the engine dies immediately.