Fuel flow ZERO

[fastfred58]

I have the SV d1000s vintage 2010 in my plane and yesterday the fuel flow went to Zero . The engine ran fine so I assume it is in the sensor. What is the trouble shoot process for this and do I have to remove it to clean it?

 

[DBRV10]

You may have a small amount of debris jamming the little turbine inside.....or a connection problem somewhere.

 

[airguy]

You didn't mention what type of flow sensor you have - if it's the common FT-60 "red cube" then it has a turbine inside that spins with the fuel flow, and an optical pickup to send pulses to the EMS box. The turbine could be jammed and not moving (it will still let the fuel flow through) or - much more likely - you have a bad wire to the device. There should be power and ground plus one signal wire to the EMS. Lose any of those three, and you've lost your fuel flow.

If you confirm the wiring is good and suspect the turbine inside is bad - you will destroy the unit by unscrewing it and opening it up. There is a very fine wire laid in the cap with epoxy, it is not possible to open the unit without breaking the wire. Do what you can to try to flush or clean the unit without opening it up, and if that doesn't work then send it to the round file and replace it.

 

[swatson999]

If it's a Red Cube, "conventional wisdom" (such as VAF) indicates that they just give up the ghost on a pretty regular basis around 700-1000 hours. Just replaced mine at 770 hours. It wasn't clogged or anything else, it just started dropping from normal FF to very low or 0, then after some period of time would go back up, then back down, etc.

Not sure what the failure root cause is...heck, it's a pretty cheap and easy replacement, by comparison to other things in aviation. Still, wish it was more reliable in the long run...

 

[preid]

My second cube was replaced within a year, fortunately under warranty, my 2010 red cube went out after about 500 hours. fuel is good, sits in tunnel not engine area.
There is a cleaning process you can try, (take out and drain as menfilmed) but I gather a new one is going to be the final option.
it works great and many have had theirs for years without an issue, hoping My third one will last much longer, but even if it doesn’t they are worth replacin, IMO

 

[kellym]

The red cube originally had spade connectors. For the pulses involved, those connections are very unreliable. Dynon changed to the Electronics International OLC connectors sometime ago. In most cases just fixing those connections will eliminate most problems. It made my connections so much better that I had to lower the K factor significantly.

 

[swatson999]

Mine failed despite not using spade connectors, just to throw that info into the mix. I had replaced them hundreds of hours ago with Deutsch DTM connectors.

 

[fastfred58]

You may have a small amount of debris jamming the little turbine inside.....or a connection problem somewhere.

Is there a process to clean it out

 

[airguy]

Is there a process to clean it out

Not a good one - remove it from the line and you can flush fluid through it backward to try and dislodge anything in there - blow through it by mouth and you should hear the turbine spin. The manaufacturer says not to blow compressed air through it as you can damage the turbine.