Stumblin Bumblin Z

[scottfab]

Originally Posted by Paul Workman

I agree with you - far as a static test goes. Mine does that too. However, under dynamic load (pressure gauge taped to the windshield), with just the primary pump, pressure is in the 44-46 range (depeding on load). But, as soon as the throttle/rpm reaches the threshold where the secondary pump activates, pressure pops to about 52 ± a bit and holds steady.

For what its worth, when the secondary pump was not working, FP dropped to 38# at WOT, and the AFR went very lean!

If the secondary is not working at all it does not surprise me to see <40lb.
However, if you get one failing like mine mid 40s is not good enough.
Mine Now starts with 52lb and stays there until sustained WOT then drops to about 49lb then shoots back to 52lb when the secondary pump kicks in.
At this point I think he needs to rule out the basic stuff before looking at secondary actuators. It's hard enough chasing one's tail but if your chasing the wrong tail? She better be worth it
By what he's describing the secondary fuel pump could very well be seized up. Best rule that out.