Another Fuel pressure / pump question.

[kf6iat]

Today, we returned from Tucson... Great flight at 8,500, smooth and faster than going out on Friday. As we were climbing out, I turned off the electric pump,,, and the pressure dropped, I turned on the electric pump again, and up came the pressure. turned ot off again, and again the pressure dropped of, almost to zero.. one more time cycled the electric pump and the 3rd time the pressure stabilized at a higher value, slightly above the middle mark on the Gage, like normal.

When it came time to change tanks, I again turned on the electric pump... normal process.... switched tanks and again, pressure dropped to zero... did that once more and left the electric pump on the rest of the flight home..

I remember reading a thread that was like this problem sometime last year, and did a search of all fuel pump related threads, but did not find that one that I was thinking of.

Is there not a pressure one way valve in the electric pump that can back feed and cause this problem??... At least that is what I remember.... need to locate the photo of the electric pump that is on my plane, I know I have one, and will post it. There was also an AD on the engine driven pump but it was verified at the pre-buy to be completed... more to follow.

1967 Cherokee 140, with an O-360-A4A engine.
SB 1006 complied with last year, new hoses and vents...

Photo must be on my work computer... will post next week if we need that bit of info...

 

[flyguydon]

 

[killrocks]

 

[kf6iat]

 

[kf6iat]

 

[kf6iat]