CKeller
Premium Member
- Joined
- Aug 18, 2006
- Messages
- 268
- Reaction score
- 25
So there I was inverted at 5000'...flipped it back upright and flew straight and level for a couple heartbeats...all seems normal...then the engine surges. I look down and see the fuel pressure climbing from 12 gph (where I'd set it) up to 16 gph for one loooonnng second, then back down to 12.
Specifics: newly-overhauled O-360-A1A with Bendix/Precision RSA-5A1D fuel injection and inverted oil, CS prop. 3/4 full main fuel tank, Dukes electric fuel boost pump ON. 2500 rpm, 25 inches of MP.
I was able to duplicate this event on subsequent aerobatic maneuvers. I have not see the governor slip (no change in RPM) but have not noticed if the MP changes. I've only seen fuel pressure change. The fuel pressure does not drop (as in gulping in a bit of air), it RISES.
I've talked to Don Riviera at Airflow Performance; Airflow overhauled my fuel system while the engine was out. He's also at a loss as to what could cause this, but his comment was that fuel pressure/flow does not change without a change in airflow at the injection throttle body - in other words, it must be accompanied by adrop in manifold pressure ora rise in RPM. He's asked me to go out and duplicate the situation and take more notes on other engine parameters, i.e. does it happen with a fluctuation in oil pressure?
I'm open to other ideas here. This is a little unnerving.
Colleen
Specifics: newly-overhauled O-360-A1A with Bendix/Precision RSA-5A1D fuel injection and inverted oil, CS prop. 3/4 full main fuel tank, Dukes electric fuel boost pump ON. 2500 rpm, 25 inches of MP.
I was able to duplicate this event on subsequent aerobatic maneuvers. I have not see the governor slip (no change in RPM) but have not noticed if the MP changes. I've only seen fuel pressure change. The fuel pressure does not drop (as in gulping in a bit of air), it RISES.
I've talked to Don Riviera at Airflow Performance; Airflow overhauled my fuel system while the engine was out. He's also at a loss as to what could cause this, but his comment was that fuel pressure/flow does not change without a change in airflow at the injection throttle body - in other words, it must be accompanied by adrop in manifold pressure ora rise in RPM. He's asked me to go out and duplicate the situation and take more notes on other engine parameters, i.e. does it happen with a fluctuation in oil pressure?
I'm open to other ideas here. This is a little unnerving.
Colleen
