Rotax 912 fuel pump problems

sethdallob · Post by **sethdallob** » Wed Jul 01, 2009 5:27 pm

I frequently lose fuel pressure on takeoff, during a descent, and sometimes on level flight for no apparent reason. When it falls below the red mark on the fuel pressure gauge, I turn on the auxiliary electric fuel pump.

I've been through 2 fuel pumps from Rotax, and both the aircraft distributor and the Rotax parts house say "the fuel pump is crap - ever since they changed the manufacturer in 2006 they are crap" Are other LSA owners experiencing the same problems with fuel pressure? Is it just something to live with?

rfane · Post by **rfane** » Wed Jul 01, 2009 5:45 pm

When the pressure drops, do you experience any engine roughness or change? If not, I suspect that the sensor is bad. The original one that came on my CT, was crap, and would report low fuel pressure at times. It eventually got to the point that I couldn't even get the plane started and taxiing before the EMS was giving me warnings. It would also happen during cruise. Throughout it all, the engine never missed a beat. I ended up getting a new sensor that mounts to the firewall, and not on the engine itself, and haven't had any issues for over 2 years.

sethdallob · Post by **sethdallob** » Wed Jul 01, 2009 5:49 pm

I haven't had the guts to let it drop all the way. comperini, though, has had a partial power loss on takeoff.

I've heard some people think it's the sensor, others say it's the heat, etc. The distributor says no, it's the pump - they've tried fooling around with those other parts - it's not the plane, it's not the sensor, it's not the heat, it's the pump, and Rotax won't acknowledge the problem.

comperini · Post by **comperini** » Wed Jul 01, 2009 6:28 pm

rfane wrote:When the pressure drops, do you experience any engine roughness or change? If not, I suspect that the sensor is bad.

We have no "sensor". Its not an electronic fuel pressure indicator. Its a simple analog Rotax fuel pressure gauge (driven by the pressure in the line).

vwvectors · Post by **vwvectors** » Thu Jul 02, 2009 9:36 am

Seth do u have a dynon ems ? U are right about the pumps that that the original pieberg pumps are the one's to have the other brand is crap & have a high failure rate.

sethdallob · Post by **sethdallob** » Thu Jul 02, 2009 9:41 pm

I have a FlyDat EMS, but my fuel pressure gauge is just the analog Rotax one that reads directly off the fuel line.

vwvectors · Post by **vwvectors** » Thu Jul 02, 2009 10:48 pm

Rfane is right check the sensor they do go bad often.