Fuel flow calibration

[amillet]

When We bought out J model 12 years ago the Shadin Mimi-Flo fuel flow was not accurate.  I adjusted the K factor (pull the unit from the panel & move the microswitches, trial & error, it was a pain in the a$$).  I finally got it adjusted so that a fill up would be a few tenths of a gallon of the Shadin's fuel used number.  Now the Shadin shows that I've used 5 or 6 gallons more than actual.  Do I need a new transducer?  I'm considering upgrading the JPI 700 to something that includes fuel flow.  All my primary gauges are working fine so I don't want to spend for a JPI  900 or 930.  Suggestions?

[par]

Can't comment specifically on your device but I have an EDM-830 with FF and adjusting it is a very simple process. My first fuel flow transducer malfunctioned and I had to replace it but it would show zero most of the time and erratic readings other times. A replacement unit fixed the issue. Changing the K-factor is a very simple process using the formula provided in the instruction book. It has been great so far and I will never fly another plane without it.

[amillet]

Will a 730 or 830 fit in the place of my Shadin & JPI?

[kpaul]

You can add fuel flow to your 700.  Mine has it and works very well.

[gsxrpilot]

If you're gonna replace the 700, take a serious look at the Insight G2. It includes fuel flow, has a much better, easy to read display, has the best/easiest data logging of any engine monitor and fits in the same hole. It will be the same cost as the cheapest JPI or EI unit.

Also, the fuel flow function on the G2 is much easier to use than the Shadin you've got now. It's also much easier to use than the JPI EDM-700 fuel flow function as well.

[kpaul]

1 minute ago, daver328 said:

That may be a better idea?

Mine was installed when I purchased the airplane, however it looks like it is $275 + install.  I am not sure which part you need, but I am sure someone smarter than I am will know.

http://www.aircraftspruce.com/catalog/inpages/edm700transducfuel.php?clickkey=2004608

http://www.aircraftspruce.com/catalog/inpages/edm700transducgrav.php?clickkey=2004608

[amillet]

Just now, gsxrpilot said:

If you're gonna replace the 700, take a serious look at the Insight G2. It includes fuel flow, has a much better, easy to read display, has the best/easiest data logging of any engine monitor and fits in the same hole. It will be the same cost as the cheapest JPI or EI unit.

Also, the fuel flow function on the G2 is much easier to use than the Shadin you've got now. It's also much easier to use than the JPI EDM-700 fuel flow function as well.

I'll check it out.  Is that what you installed in your new panel?

[peevee]

If you want to upgrade, that's cool.

If you want to save a few bucks and put the upgrade off you might soak the transducer in carb cleaner over night. Sometimes the wheel gets gummed up. It's a cheap temp fix if it helps.

[carusoam]

would you prefer to fix the problem, or go directly to the newer technology?

 

Accuracy in fuel flow usually doesn't change...

It can take a lot of effort to get the accuracy at first...  install errors are common, then calibration...

Following the instructions for the calibration can be hard to understand at first.

 

Once everything is working... but now the accuracy is going away.  

 

There are a few errors that have been mentioned on MS.

1) dirt and gunk stuck in the sensor or dirty vanes.  Taking up volume that is used for fuel...

2) dirt and gunk in the sensor that keeps the wheel from spinning.

3) air leaking into the system.  Air gets sucked in from seal leaks upstream.  The bubbles get counted as fuel...

 

Some of these challenges may still exist with a newly swapped in sensor...

 

PP thoughts that come to mind...

Happy Sunday,

-a- 

[gsxrpilot]

11 minutes ago, amillet said:

I'll check it out.  Is that what you installed in your new panel?

No, I went full Primary replacement with the JPI EDM-900 in my M20K 252.  But I had installed the G2 in my previous Mooney, an M20C. I did a ton of research and settled on the G2 as the most cost effective way to get a basic engine monitor with all the extras like fuel flow, OAT, carb temp, etc.  Once it was installed, almost everyone who flew in my plane wanted one. The display is beautiful. It makes the JPI and the EI look like 1980's technology.

But the best part is the data logging. Again, this feature is extra, or extra cables, or extra ports required to be installed with the JPI or EI. With the G2 nothing extra is required. There is an SD card in the face of the unit. It has enough space to hold complete engine logs for more than 2000 hours of flying or past your TBO without having to erase or overwrite anything. To download the logs, just eject the SD card, insert it into your laptop and download the files. Works on PC/Mac/iPad/anything. Then stick the card back in the unit and continue flying.

Both JPI and EI make really nice higher end units. But if you're looking for an entry level engine monitor, the G2 is the way to go.

[Oscar Avalle]

I also installed a 900 and replaced all my gauges. Calibration is not an easy task as you know. It took me a while to get it right. One thing that I noticed is that it also depends on who tops off your tanks. My experience was that depending on who does it you may get 2 or even more gallons below what you should have gotten. This error compounds and it may mislead you in terms of what your instrument tells you. My suggestion would be to make sure that you top off the tanks fully and log three of four two hour flights to double check on your calibration. Just keep an eye on the refueling process to make sure that you top off your tanks.

Oscar