JPI 900 Transducer location on M20J

[L39Driver]

Anyone have any photos on where they located their fuel flow transducer for the JPI 900 install?

Thank you David

[ArtVandelay]

Mine is on top of the pilots footwell (horizontal position).

[KSMooniac]

Mine is inline between the fuel pump and servo, sitting above the induction tubes near the sump. I can take a pic in a couple weeks if needed when it is time for the annual.

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[jetdriven]

Same here. It’s the only conforming place that fits. 

[carusoam]

+1 on the firewall... M20R...

Some IO360s got the sensor mounted close to the cylinders... it mechanically made sense for some reason... but sub-optimal for a lot of reasons...

Pay attention to the instructions for mounting the sensor.... Angles and distance from hardware, into and out of....

Good to copy a known good installation...

PP thoughts only, not a mechanic...

Best regards,

-a-

[flyboy0681]

6 hours ago, carusoam said:

+1 on the firewall... M20R...

Some IO360s got the sensor mounted close to the cylinders... it mechanically made sense for some reason... but sub-optimal for a lot of reasons...

 

When the factory transducer died, maybe seven years ago, we had a Red Cube installed in the original location. That unit lasted about a year. The replacement unit also lasted about a year. When that one died I contacted the manufacturer, who said it needs to be installed away from serious vibration and heat. It was at that time that we had it installed on the firewall. The third unit has been functioning flawlessly ever since.

[Marauder]

Anyone have any photos on where they located their fuel flow transducer for the JPI 900 install?
Thank you David

Mine is on the firewall on the pilot’s side. Should be a red unit.




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[flyboy0681]

Here's a picture when the overhaul was installed (by the red arrow.)

[Marauder]

12 minutes ago, flyboy0681 said:

Here's a picture when the overhaul was installed (by the red arrow.)

Interesting that they wrapped your's up in a heat shield. Where was it mounted?

[flyboy0681]

14 minutes ago, Marauder said:

Interesting that they wrapped your's up in a heat shield. Where was it mounted?

It was originally mounted somewhere attached to the engine block where it was subject to a lot of vibration.

[bradp]

It’s not supposed to be mounted directly to the servo. Ask me how I know.  :-). 

[Yetti]

1 hour ago, Marauder said:

 

Mine is on the firewall on the pilot’s side. Should be a red unit.




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Why not firesleeve the main lines carrying fuel?  Asking for a friend.

[ArtVandelay]

Tom

[jetdriven]

9 hours ago, Marauder said:

 

Mine is on the firewall on the pilot’s side. Should be a red unit.




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Hate to sound critical here, but those hard elbows both forward and after the red cube are major violations of the instructions. If you want it to read accurately, it can’t  wirh all that  turbulence going through it. You need straight fittings and gentle bends before and after the transducer.  If it doesn’t read accurately, then the fuel remaining is off. And it’s off more at some times than others. 

[PT20J]

This is the Mooney factory mounting for the Floscan (now owned by JPI) transducer on the IO-360. The bracket mounts to a couple of studs on the top of the sump non the left side of the engine.

ing

In this scheme, the transducer is actually mounted upside down. The reason its supposed to be mounted with the wires up is that there is a little vent on the top that way to vent any vapor that may get into it. I talked to a tech rep at JPI and he said it's not all that important. I was trying to improve the accuracy of my system and I went to some trouble to mount it in the same position but right side up (had to make a new bracket with some standoffs) and it made absolutely no difference. 

Skip

[Guest]

On 1/17/2020 at 12:48 PM, Marauder said:

 

Mine is on the firewall on the pilot’s side. Should be a red unit.




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A few questions/ comments.

Why are your fuel pressure transducers not connected to the pressure port on the fuel servo finger screen?

Normally the fittings on the flow transducer are supposed to be straight not 90 degree elbows.  There are preformed 90 degree hose ends which reduce turbulent flows for tight installations.

Clarence
 

[FloridaMan]

On 1/17/2020 at 2:54 AM, carusoam said:

+1 on the firewall... M20R...

Some IO360s got the sensor mounted close to the cylinders... it mechanically made sense for some reason... but sub-optimal for a lot of reasons...

Pay attention to the instructions for mounting the sensor.... Angles and distance from hardware, into and out of....

Good to copy a known good installation...

PP thoughts only, not a mechanic...

Best regards,

-a-

I think mine's mounted on top of my engine near the spider. I think it should be in a location with a lot of vibration as the one in my Rocket sticks and the one on my M20F is dead-nuts accurate. 

[jetdriven]

Continentals are a different matter entirely. They have two.  One to count the fuel through the servo and one to count the fuel returned to the tank.  It subtracts #2 from #1 to determine fuel burned. 

[bradp]

Mine is mounted on that little stand off from the sump like in the picture skip put up.  IO-360

[MinneMooney]

Turbine flow meters are generally recommended to have 10 - 25 pipe diameters (depending on the type of flow disturbing fitting, 90deg elbow, t-fitting) of a straight length of pipe upstream and 5 pipe diameters downstream to smooth flow.

[ArtVandelay]

12 hours ago, jetdriven said:

Hate to sound critical here, but those hard elbows both forward and after the red cube are major violations of the instructions. If you want it to read accurately, it can’t  wirh all that  turbulence going through it. You need straight fittings and gentle bends before and after the transducer.  If it doesn’t read accurately, then the fuel remaining is off. And it’s off more at some times than others. 

Not to jump on the bandwagon, but is the probe wires cabled tied to a spark plug wire?  If yes, that’s not recommended as well.

[ohdub]

This is how Clarence installed them on the firewall of my J

[EricJ]

15 minutes ago, ohdub said:

This is how Clarence installed them on the firewall of my J

That's a really good example of how stuff should be marked, too.    The shop that did mine left pieces of painter's tape with sharpie scribbling on them.

 

[Guest]

6 hours ago, jetdriven said:

Continentals are a different matter entirely. They have two.  One to count the fuel through the servo and one to count the fuel returned to the tank.  It subtracts #2 from #1 to determine fuel burned. 

I’ve only seen this once on a Bonanza that had a pressure carburetor.  All other TCM engine use only one.

Clarence

[carusoam]

Bonanza must have an interesting fuel injection system..?

With an automotive style FI system... fuel pressure is maintained no matter how much fuel gets used by the engine... a bunch of excess fuel goes back to the tank...

It would be important to see how much went to the tank and compare how much was sent towards the engine and subtract the two...

As far as I know... I have one FF sensor, and the return line isn’t operational continuously...

But... pull the mixture, turn on the electric pump, ... FF is sent back to the fuel selector and off to the chosen tank... this is used to cool the fuel lines for a hot start...

Some planes, the excess fuel sent back always goes back to one tank... more simple, but more confusing to know where the fuel is at all times...

Looks like I have an opportunity to learn something new... 
 

When it comes to liquid flow sensors...

• long 
• straight
• entries and exits
• distances are measured in IDs of the tube...
• 90° elbows are terrible
• 45° elbows are better
• Some flow sensors have a bearing support on the bottom, turning them upside may add a challenge...
• Stickiness can be a challenge... 100LL likes to form deposits when able...
• Vents on the FF sensor? Tell me more...
• Washing the paddle wheel sensor may improve its operation

PP thoughts only, not a mechanic...

Best regards,

-a-