Loooow Fuel Pressure!

[67ModStang]

So i just replaced the motor/pump on my Airdog2 about a week ago...got my fuel pressure gauge hooked up and i'm reading a very erratic 30-40 psi with engine off and at idle, about 20 cruising and almost nothing at WOT!!! Is there anything else that would cause such low pressures or did I get a bum replacement pump from Airdog??

[2003kingranch]

Your gauge could be messed up as well. Just a thought


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[67ModStang]

I dont think it is. I can hear the pump changing pitch with the pressure change and every so often it will jump around 50psi accompanied by a higher pitch sound from the pump. At WOT there is a definite power loss.

[2003kingranch]

Well I wouldn't drive it like that.sounds like you got a bad pump


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[DoubleDpsd]

what else would cause low fuel pressure outside of the pump?

[67ModStang]

Thats what i want to be sure of. Only other thing I can think of is maybe its sucking air...but wouldnt that cause it to no-start?

[dannyboy950]

If it's not a gauge issue it has to be the pump or its regulator. A leak in the system would be constant, not turn itself on an off.

[67ModStang]

Made some progress today. The pump is good...I hooked up some extra fuel hose I had to the pump intake and put it directly into a can of fuel...55-60psi. I need to check out the fitting that goes into the tank now to see if I can find the air leak