Fuel pressure surge

[Bavafa]

Has anyone experience fuel pressure surge? My fuel pressure surges to about 50 PSI for about a couple of seconds when the fuel boost pump is on. It happens almost every time but have found no specific pattern as under what condition it goes up. My engine driven pump runs at about 27 PSI and with the electric pump it goes to about 33 PSI. So was wondering if any one has any inside to this and if it is an issue or just normal with most systems. I have a IO-360-M1B engine and RV7A

Thanks in advance
Mehrdad

[Don at Airflow]

If you have an Airflow boost pump, the relief is a poppet valve, which seats in an O-ring. Depending on the fuel you use the O-ring may swell a little and cause the poppet to stick a little on the first un-seat. This is pretty normal for this type of relief valve arrangement and is no problem for the rest of the fuel injection system. If you want you can contact me at airflow2@bellsouth.net, relay this message, and we can mail you a Fluorosilicone O-ring to replace the Buna O-ring that is the factory part. This may or may not keep the valve from sticking on the initial start of the boost pump.

Don

[vlittle]

Don, is the AFP fuel pump assembly tolerant of alchohol contamination?

Thanks, Vern

[Don at Airflow]

No problem. As long as alcohol does not sit in the pump. We used these pumps on methanol mini sprint cars, just flushed out with gasoline after having funhttp://www.vansairforce.com/community/images/smilies/smile.gif

Don