Flowscan Lying?

[Norseman]

Noticed it about 3 weeks ago: GPH showing less and MPG showing more:
In other words fuel flow was cut in 1/2 to 1/3 of normal.
No Santa Claus in my life so we have a problem.

First of all, I have not touched the calibration controls in well over a year and had the system calibrated to within 2-3% as verified by a recent “fill-up” of the tank.

After a quick google search some comments was vacuum leak at the filters or in the lines.
I looked for fuel coming out, as it could, if air can come in.
The Racor looked good, drained the bowl, fuel was clean as a whistle, no problems noted at or around the fittings.
The engine fuel filter however had a small leak underneath where the water sensor screws in.
I tightened the sensor (part number X0719005370) and it seems to be dry now.
Will take the boat out today to check the Flowsacan numbers, but the solution seems too easy, doubt a very tiny leak at the diesel filter could affect the flow numbers.

Any other ideas, anybody else had a similar problem?
Any serviceable parts in the Flowscan system?
Heard Flowscan went out of business a year or two ago, no service hotline to call.
Any ideas?

[Norseman]

Looks like Flowscan is back in business after all:

FloScan was bought out last year and is under new ownership. The new owner has continued production of the original line of aircraft fuel flow sensors and we are working on introducing a new line of gas and diesel fuel monitoring display instrumentation by the latter part of this year or early 2020. At this time, we can still supply the following FloScan models or spare parts used in older systems:

- gasoline and diesel fuel flow sensors used on marine and generator applications
- fuel pulsation damper and flow homogenizer canisters
- FloNET / NMEA 2000 Interface Systems (gas and diesel models)
- TwinScan GPH/LPH and Tach Systems (twin gasoline models only)

Unfortunately, the Multifunction Meter models (7000/8000/9000 Series) are no longer available for resale. However, it may be possible to repair existing instrument heads depending on the condition of the unit.”

Sent them a question on my system and why it is under-reporting flow?
Here is the answer:

While at the dock, perform the attached test to verify the individual supply and return flow readings that the instrument head is receiving. If you can't easily reach the plug, simply start your engine and as soon as the instrument head "lights-up", quickly cycle the Totalizer Reset Switch from its run position to the reset position then back to the run position two or three times. Send me the test results for analysis.

Regards,
Joe Dydasco
FloScan, Inc.

Here is the test:

80EF62B7-BD0E-4AF2-B812-07B98C230387.jpeg

32DC0755-6E98-460B-8CC2-873BFE87AF02.jpeg

[Norseman]

Did the diagnostic test today, got these results:

969A217D-31D9-49AB-9C31-94E882E819BD.jpeg

Joe at Flowscan said there is something strange about these numbers and asked me to take the boat out and the record the numbers under load and higher power settings, 3,000 should be ok he said.

Will do in a few days.
Curious if anybody else with the same engine and the Flowscan system gets similar numbers..?

[Norseman]

I got new numbers from idle up to 3000 RPM and sent to FloScan, here is their response:

It appears that the 231 Series forward flow sensor is no longer putting out a correct flow rate. One thing you can try is to remove it and fill/soak it overnight with carburetor cleaner. You can give it a few blasts of carb cleaner after the soak to help clean off the optical parts within the unit. Last option is to purchase a new 231 Series flow sensor for $325 plus shipping.

Regards,
Joe

This is the culprit

9CF74F11-B0D2-4A6E-9DA2-9B93482D0D18.jpeg