Fuel flow meter on MPI engines

W

WALSHIE

Well-known member
Member
Joined
Jan 1, 2000
RO Number
2124
Messages
2,373
Years ago I installed fuel flow meters on my carbuerated twin 305 boat and loved them.

Now I have a 2001 Silverton with 350 Crusaders, MPI. It has low and high pressure fuel pumps with a return from the fuel rail to the tank (or maybe its the high pressure pump reservoir).

If its to the reservoir, I guess what passes through is eventually burned. However, if the fuel returns to the tank, how do you account for what is returned? Do you need 2 sensors per engine?

I did some research and did not find this to be a problem, people installed after market fuel flow meters and love them.

Any advice would be appreciated.
 
Walshie, when I installed fuel flow sensors on my carbed 454s, there was a section about systems with fuel return lines (fuel injection). i didn't pay much attention to it because it didn't apply to me. It wasn't a 2 sensor solution if I remember.
 
My 2003 Crusader 5.7L MPI engines each have FloScan 9000 tach/ hour meter/ GPH/ NMPG ( interfaced with GPS SOG for economy display)/ and fuel-used resettable totalizer.
But when I ordered the engines I stipulated they had to be returnless fuel system just so I could continue to use the FloScans. Floscan didn't/doesn't sell a fuel management system for return-type gas engines.
I also have a B&G NetEngineSystem display which provides a plethora of data directly from both engines' ECMs including GPH from which the B&G also calculates Gal.-Used and resettable totalizer for both engines. Very accurate. B&G hasn't sold those displays for a long time and I don't think they would connect to the 2001 Crusaders, not sure.

If yours do return excess pumped fuel to the tanks, you might check with Maretron who have an FFM100 system for compensating for the return flow. Their diagrams just show it for diesel engines that all have returns but it just ....might... be compatible with return gasoline systems too.

https://www.maretron.com/products/ffm100.php
 
Chris, let me know if you find a solution. I have MPI Crusader 502s with return lines in my Silverton and would very much like to add fuel flow meters.
 
Another possibility for you might be a $295/ea. Fox Gateway to connect your 2001 MEFI-3?( or MEFI-2?) ignition engines to your MFDs to display GPH and other engine data via NMEA 2000. (My engines are MEFI-4)
I don't think it calculates gallons-used or NMPG, but ECM algorithm-calculated GPH is a start. That's based on injector open time, so returned fuel is irrelevant.

https://fox-marine.com/index.php?route=product/category&path=81
 
We are looking into fuel flow transducers for my 1995 Silverton 41C with 502's. FloScan will be coming out with updated sensors either later this year or early next year. I also have the return fuel lines.
 
Like Sandy above said. I put the Fox gateways on my 2000 Mercruiser Horizon MPI. If you your GPS is is newer and has the gauges it will tell fuel burned, MPG . You have to build a backbone network(something like that} which wasn't hard to do. It has bluetooth and you can get the app and it will give you all the info capable of your ECM right to your phone. Temp,Volt and gph and a bunch of other stuff. It wont show oil pressure but I believe you can change that sending unit if you want that.
 
How can I tell if my 2001 Crusaders Captains Choice are MEFI-2/3/4? That sounds like a great app!
 
Not sure if this link will come through, but this should at least show the visual difference between the ECU s for MEFI-1&2, and MEFI-3 & 4 ( & MEFI-5).
https://www.custombuiltmotors.com/images/MEFI/mefi all.jpg

But best way I would think is just scan the engine . The scan will "discover" which MEFI-(?) version you have, once you turn the key just to Run position.
 
My diesel floscans have delivery and return sensors on both engines = 4 sensors.

I love them!

DEADLY ACCURATE !

RWS
 
Hi guys, I finally took pics of the MEFI module, it looks like I have to scan it to see if I have a 3 or 4.

Check it out in the album. https://photos.app.goo.gl/ytSgwb75QffveJ458

I'm leaning toward the FOX Gateway, that sounds perfect. I also would like to upgrade my GPS to most likely a Simrad NSS EVO3. Does anyone have experience using that unit with the Fox?

PS - thanks for the awesome tip, the last thing I want to do is cut and mess with my fuel lines!

EDIT: WAIT - F$CK, I need TWO units, oy!
 
The sticker might be on the back of it. You could also maybe send that picture to Fox.
 
You must log in or register to reply here.
Back
Top