flo scan problems

Got a flow bug. Hoping somebody has already been here. Thru many years my flo-scan system has worked well.
Now,
Stb 12v71ti reads way low on fuel use. Last weeks run under loads showed the stb using fractions of fuel compared to the port engine. Friday night I started looking into it.
In the diagnostic mode the return sensor flows more than the feed sensor at idle resulting in 0 consumption idle no load. the port main varies between .5 to 1.5 gph idle no load.
During my no load testing, the flows on all sensors bounce around a good bit but after watching them, an average comes to you.
Yep, all filters changed and same low vacuum between the engines.

All of the sensors are averaging about the same but the stb return. It flows more.The stb return sensor is showing more return, how is that possible?

I started this last night. Found the trouble shooting guide and have been going over it. all checks out. I can also swap displays and the problem stays to stb. All switches to default, 0 (except tach switches).

Anybody been here?

Just back from the bilges.
It is a PITA to remove the sensors for cleaning, I did the best south Georgia cleaning I thought of;
Drained the racors, removed filter, removed the fuel in line to the racors, removed the out line from the first flo-scan (fuel in) sensor. Blew in/out lots of air. Figure 90 psi @ 8 to 10 cfm, for several minuets. When compressor tapered off, charged up and did it again for several attempts.
Pulled the return line off the fuel cooler, (Detroit's cool the fuel on the return side), blew air thru as above. This would give the return sensor a good,,,, blow. Can really hear the fuel bubble in the forward (low on fuel) tank.
So, I feel good the sensors are mostly clear. Charge with fresh fuel (another new filter), after 15 minutes fast idle, same problem. Return sensor spinning faster than feed sensor.
Were only talking (no load) approx 1 gph error (drops in a buck error) I have NOT changed any symptom.
Oh, while charging with air, no leaks detected. All fittings are still bone dry. Would figure if any joint leaks, a fitting would get a lil wet if blown a little (works for me).

I'm on to the rum...,
rc

Under load, the stb shows to start using fuel, @ cruise, near 1/3 of port eng consumption. Port eng is correct.

Was hoping a blast of air would clear anything on the paddle wheels. Oh Wel....

You know your tapping on me for a 4 + year old thread.

I had two problems thru the years. One sender did fail and was determined bad by the diagnostic with no pulses or signal and knowing the wheel was turning.
My second problem was when a wheel was turning slow. The wheel was covered with a water/diesel snot and after cleaning, still required many hours to finally clear out with fresh fuel and tank cleaner.
I have another thread with this water/fuel/snot problem.

LOL, at one time, my flow meters were showing I was making fuel.

My flow scans were never accurate and never will be (god knows I have tried). But they are a tool to use to help avoid problems.
When you start in the morning, make note of the flow, if it changes rapidly (+ or -), there is a problem, go below and check your low pressure (VACUUM) gauges.
Use the factory fuel flow graphs to plan your day, never your flowscans.

Not a problem. Probably needed to finalize the thread anyway.
I don't think you can see the date on a phone or pad anyway.
Only so much stuff you can put on a lil screen.
That's why I still luv my large desk top screen.

Diaphragm? What model sender were you working on?

Oh, small sender. Pulsation dampener. I'm on page now.