Fuel System problems

by **MV Case Jr** » Mon Sep 15, 2008 5:28 pm

Peter ,
Does your fuel pump have the cooling air shroud around it ???

Marty

by **Peter Murphy** » Tue Sep 16, 2008 12:45 am

It does, it's just 3/4 or 1" scat tubing that feeds from the back of the engine to the fuel pump cooling shroud. Hopefully my mechanic will have time to start on it tomorrow. Been waiting for the pump again from Aircraft Accessories, the new one the sold us was clocked wrong. (Left hand orientation?) Thanks for the idea; the pump certainly is telling us it is getting too hot. I think we are close, hope to post an update tomorrow. - Peter

by **Peter Murphy** » Wed Sep 17, 2008 2:44 am

Romec reinstalled today along w/ overhauled selector. Ran engine w/ a section of clear tubing hanging down on firewall and no bubbles were seen in outside sunny conditions. Looking forward to committing aviation tomorrow. Pretty sure our worn out selector was the source of our air in the system. Will be keeping a close eye/ watch on the fuel pressure gauge and any fluctuations will not be ignored. Taking that to mean air in the system. Esp. vigilant when we have dry tanks. Not that I like my bladders dry but I do like my range and as Mr. Deakin says, “Be careful up there”

by **Peter Murphy** » Mon Sep 22, 2008 4:36 am

The Romec engine driven fuel pump has 5 hours on it now but I’m not happy w/ its performance or perhaps we have something else going on. The situation is the fuel pressure is fluctuating about 1gph, esp. when LOP. If you flip on the boost pumps, the pressure jumps up an additional 1- 1.5 gph more and is steady. Another indicator is on the ground, close to too lean to run, the idle cycles up and down to an over lean condition. If you switch on the boost pumps it steadies the idle. Is it possible the engine driven fuel pump isn’t supplying enough pressure/ volume to the servo? High OAT’s aggravate this. This afternoon on take off out of Bowerman Field (HQM) w/ an OAT of 15c at sea level I was getting over redline fuel flow (excellent) and making great power, just don’t think I should have to use the boost pumps to keep things stable. One last thing, we have been fighting a 1500rpm stumble, on the ground or on approach, where more throttle will make the engine die, but if you pump the throttle, (this is a Bendix RSA -5servo, I know this sounds funny) you can get above that transition point where the engine wants to bog. We are plenty rich on our rich/lean thumb wheel and I’m being told that is for the idle circuit only anyway. Ideas anyone? (Zach) Thanks in advance, - Peter Murphy

by **Zach Grant L1011jock** » Sat Sep 27, 2008 3:42 am

by **Peter Murphy** » Sun Sep 28, 2008 2:38 am

Fuel System problems

Fuel System problems

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