mileage computer for a carbureted engine

[TheTestPilot]

The sensor rotor would randomly stop rotating ,I am guessing due to stiction of the bearing ,this was with straight fuel (no ethanol) .
A clear top with a camera confirmed this ,I bought two at the same time & both do the same.
Another problem I noted ,when going WOT for Freeway on ramp RESTRICTION was so great engine almost stopped (engine h.p. approx. 65),the orifice in the sensor was approx. 1.2 mm ,this is about the size of the primary jet in my NIKKI carb.
I think orifice needs to be smaller to get the velocity to turn the rotor reliably ,did I mention when the fuel gets hot!
Regards
Tp

[P-hack]

if you have a return line, then you might measure fuel flow ultrasonically thus:

[TheTestPilot]

DOPPLER sensor sounds interesting ,but the development/learning curve for the hardware,then the code ,needs more time than I currently have available.

I have cobbled together some electronics for two pressure sensors ,either side of a fuel line restriction (say 2mm) & a reference from the ignition pulse,combine these three inputs together & this produces a variable square (pwm) just like an injector drive signal ,based on fuel flow & rpm(MPGuino compatable?).
This works on my bench ,but I have yet to order the pressure sensors , (these are $50 a sensor ,ouch & hostile liquid compatable) & test it in the real world.
There is another problem with some mechanical pumps on carb cars ,severe pulsation ,this needs to be damped if present , so the sensors are not overwhelmed ,ahh it just never ends.

I can't try this until at least Mid june when I return from Asia.

This is certainly not cheap, but if it works ,I will be extremely happy.

Tp

[P-hack]

Conceptually doppler is as simple as one of these (which is like $3), where the sender and receiver are at opposite ends of a hdpe tube. A faster crystal oscillator can help with resolution/accuracy. We are talking a couple piezos and a trip to home depot for the hardware, but some bench time with graduated cylinders/etc getting it right.

https://www.youtube.com/watch?v=-1SDVVepaP8

note: with a return line, low flow accuracy might be less of a concern for the turbines if you use two (and they aren't too restrictive). I don't know if pressure differential will work at low flow, or if it does if it will work at high flow.

[racprops]

The Van I once had that was a 84 which had a return line BUT it was at the fuel pump and thus the line to the carb was a single line so on my Zemco I placed the flow sensor in the line to the carb and it worked fine.

The ONLY place I see a return line being a problem is on 86 to 2005 Fuel injector cars with the fuel return line right at either the Throttle Body Injector or the injector fuel rails, a problem on my 93 Chevy Van with TBI which I fixed by removing the in body regulator and then placing an aftermarket fuel pressure regulator 8 inches from the TBI putting the fuel return line there and thus having a single fuel line from the regulator to the injectors and placing my fuel flow sensor in that line. This has been done and is work at this time.

On my 2000 Ford I face the return line at the fuel rail. Here I again plan on placing a aftermarket fuel pressure regulator on the fender about one foot from the fuel rail, and once again I plan on placing my fuel flow sensor it the single line from the regulator to the fuel injector rail.

I remember years ago hunting all over the internet trying to find a system that could read both the feed to the injectors AND subtract the fuel returned to the tank and thus read what was used by the motor, all in vain.

But due to that search I found this site and the much better MPGunio, which up to this point was my real time fuel use readout.

Sadly as my next efforts include either cutting back by electronic means the duty cycles of the injectors to out right cutting them out in favor of some OTHER fuel feed I now find I need a system that is not working off any of the cars electronic fuel system.

The Zemco system use ITS own speed/distance sensor in the form of magnets and a coil on the drive shaft and its own fuel flow sensor, thus is totally not connected in any way to any of the cars electric system other than power.

Due to the reports of problems with the Zemco flow sensor here I have been watching this thread hoping to find a better more accurate flow sensor..

And learning about the range limits and fuel flow limits of these other flow sensors...

I am just going to have to use the Zemco unit as is and hope as these are brand new never used units they will work for long enough to figure out how to majorly improve my MPGs in both my Van and my Ford.

I will be watching.

Hope someone finds a good unit soon.

Rich

[TheTestPilot]

Does the MPGuino not work with your injection system?

[TheTestPilot]

The Zemco system of which my last one , (no. 3) the fuel sensor started to leak when the window seal gave way , I would be careful using this sensor over about 7 psi , as the sealing is a bit crude .

[racprops]

It does BUT I plan on doing things TO my Injector system that will mess up the readings that the MPGunio uses and even shut down the injectors for another kind of fuel system and want to read what fuel that is being used.

Rich

Originally Posted by TheTestPilot

Does the MPGuino not work with your injection system?

[racprops]

That is another concern I am worried about I am running one on a 93 Chevy Van that runs only up to 15 PSI.

I am worried about running it on a car that runs around 30 to 50PSI.

Rich

Originally Posted by TheTestPilot

The Zemco system of which my last one , (no. 3) the fuel sensor started to leak when the window seal gave way , I would be careful using this sensor over about 7 psi , as the sealing is a bit crude .

[TheTestPilot]

ok , I now see your problem ,so do you want to use the mpGuino ,as the measuring device ,or you want a voltage output vs flow type sensor & read it with something else.
My Idea , was the flow sensor could be connected to The MPGuino without messing with the standard code .