fuel flow reads 0 gph

[GeorgeC]

My plane has an Insight G2 with fuel flow. A couple of years ago, it began to read erratically, and finally read 0.0 gph. A local shop cleaned out the transducer, which healed it for a while, but now it's back to reading zero. Are there other things that can be done, or do the transducers eventually go bad and need to be replaced?

 

[Bell206]

Are there other things that can be done, or do the transducers eventually go bad and need to be replaced?

Check the electrical side. While some types of transducers do fail over time the newer ones tend to last for a long time. What I have seen in the past are the wire connections at the transducer and/or the connector are breaking down, especially if its a solder joint. When you clean them and reinstall the unit the electrical connection is "remade" but then fails again as the connection readjusts itself. Maybe give Insight tech a call for additional checks?

 

[bradg33]

What transducer is it? If it's reading straight zero, check the wiring connections. It should have 3 wires: power, signal, ground. Most of the systems work the same, so you *should* be able to take the white signal wire and, with the system on, tap it to ground. If it shows flow, the head unit/wiring is OK and you've probably got a bad transducer. If tapping it to ground doesn't register anything on the unit, you've got a wiring or head unit problem.

If the transducer is an EI red cube, it may just need replacement. They're not the most robust things in the world; fortunately, they're relatively inexpensive (in airplane terms).

 

[Chip Sylverne]

Had that happen recently with my Shadin. Cleaned it a couple years ago, but it gave up the ghost. Replaced it with a Floscan 201. Wasn't expensive. Actually Shadin had the best price, under $200.

 

[MajorTurbulence]

In the past, checking the crimps on the wiring was often a culprit, but if not, that EI transducer needed replacement.

 

[Jesse Saint]

It's not unheard of for them to fail. Start with checking the connections, but it's possible the little wheel in there has seized up and cleaning may work for a short time, but your best option is probably to replace it.

 

[GeorgeC]

What transducer is it? If it's reading straight zero, check the wiring connections. It should have 3 wires: power, signal, ground. Most of the systems work the same, so you *should* be able to take the white signal wire and, with the system on, tap it to ground. If it shows flow, the head unit/wiring is OK and you've probably got a bad transducer. If tapping it to ground doesn't register anything on the unit, you've got a wiring or head unit problem.

If the transducer is an EI red cube, it may just need replacement. They're not the most robust things in the world; fortunately, they're relatively inexpensive (in airplane terms).

It's an Insight (p/n 1000-004-5). I unscrewed the connector and the contacts looked clean. It read about 30gph on the second takeoff of the day. I'll need to bring my contact cleaner next time...

 

[NordicDave]

@GeorgeC I had the exact same happen to me. It's the fuel flow meter and they cannot be cleaned or repaired. Depending on nearby heat sources, wrapping the transducer with firesleeve helps with longevity.

Best of luck sorting it out.