Fuel Gauge upgrade

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Mog
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Re: Fuel Gauge upgrade

Post by Mog »

A bit of confusion there. I’m asking if I can swap the senders out without removing the headliner. The zipper for the liner is only about 10” and just behind the middle of the wing. So it’s a long reach to get to the sender. I haven’t pulled the upper fairing off yet to see how accessible the sender is from the top side. I’m very good at working blind in areas like this but I can see this being a tricky spot to work while making sure everything is well sealed and such.

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Re: Fuel Gauge upgrade

Post by Old Piper »

Mog,

Small hands help, but you should be able to change out without removal of headliner.
It may require removal of wing root tape though, for rotation of sender.. Take top and bottom wing fairing off.

You' may need plenty of Patience and Bandaids.

Good luck.

Tom

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Mog
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Re: Fuel Gauge upgrade

Post by Mog »

Small hands I do not have. But they are exceptionally nimble for their size due to a lifetime of working on vehicles.

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riverbuggy
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Re: Fuel Gauge upgrade

Post by riverbuggy »

I unscrewed the wing tank cover, and rolled it forward a bit. Worked great, and had plenty of room to work.
Ray
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flyusn99
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Re: Fuel Gauge upgrade

Post by flyusn99 »

Mog,
Gotcha, as has been previously stated the best way to swap the senders is to take the top wing fairing off, remove the duct tape under the fairing and then open the tank cover up and you can get at the sender from the top. I would think it would be near impossible to do everything thru the headliner without royally messing it up. Hope that helps.

James

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Mog
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Re: Fuel Gauge upgrade

Post by Mog »

I can say with certainty that unbolting the fuel tank wing skin is the only practical way to change senders. Not that it can’t be done, but it would be hugely inconvenient and painful if you don’t have tiny hands.

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Andy Young
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Re: Fuel Gauge upgrade

Post by Andy Young »

Removing the wing also works. ;-)

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Mog
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Re: Fuel Gauge upgrade

Post by Mog »

Hah, yeah I suppose that’s an option as well.

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Mog
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Re: Fuel Gauge upgrade

Post by Mog »

Ok, so some notes for other Maules Installing CiES senders with a JPI900

• Wire all sender wires directly to the JPI harness, do not ground at the airframe at all.
• Ground a sender attach bolt to the airframe only
• The JPI factory split harness gets rewired per CiES instructions
• The P5 harness that came with the JPI should have main and aux pig tails. For frequency mode you will use the Aux pigtail for the main tanks (not clear on what you do for the aux tanks if you have them).
• If you do not have the aux pig tail you will either need a new harness from JPI or you will need to repin the P5 serial plug to allow readings to input to the aux pins. This is shown sort of on the CiES website in their installation manual.
• You will also have to set the JPI to read frequency even with the update from JPI. At minimum you will need to confirm this setting in the main factory settings.
• If you request an update from JPI I suggest you call them 1-2 days after sending in the RMA request to be sure they are processing your order. If you have a P5 harness with the main and aux pigtail you should not need to get the new harness from JPI.
• Be sure to get slightly longer hardware for the CiES mounting bolts. I used 1/2 long 10/32 Allen head bolts from spruce.
• You can conceivably use the olde sender wires from the factory to supply the CiES units with 12V bus power but I did run new wire.
• Buy the frequency only senders from CiES. You do not need the green wire senders

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drak130
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Re: Fuel Gauge upgrade

Post by drak130 »

So what you are saying is that it is not plug and play? All kidding aside, thanks for the update. Let us know what you think of the performance as you get some time under your wings.

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Re: Fuel Gauge upgrade

Post by Mog »

CiES does make a voltage based version that is mostly plug and play. But I wanted the frequency based to reduce the number of possible reasons for the reported fuel to be wrong. So I paid the price to get what I wanted.

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Re: Fuel Gauge upgrade

Post by Mog »

Also, to give you an idea of what changes on the EDM900.

• Fuel gauge bar graph now has actual estimated gallons below it. Presumably this should be accurate to the gallon in calibrated orientation.
• If the fuel left in tanks does not reasonably match the fuel used based on last fill up you will get a yellow warning saying fuel mismatch.

This is huge for me and inspires great confidence in my fuel system. A visual inspection via fuel caps is a must, but the gauge to reinforce what I saw is great.

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drak130
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Re: Fuel Gauge upgrade

Post by drak130 »

Folks that have done the CiES upgrade, having some issues with the installation.

Have not been able to verify myself as my real job is getting its pound of flesh from me. This is from my A&P (great guy by the way):

-Install went well considering the tight quarters
-Fuel read-outs to a CGR-30
-Calibration went well
-All gauges read accurate full
-With engine running all quantities drop 2gal for the mains and 1.5 gal for the aux
-Turn the alternator off, gauges return to full indications
-A&P called CiES who claimed he should have used shielded wire which is not indicated in the installation instructions.
-The only other electrical components out on the wing are the LED nav lights/strobes and the aux pumps

Before we/he tears it all apart again and accomplishes a complete re-wire does anyone have any suggestions or experience with this issue?

I throw myself on the mercy of the court.

Thanks in advance
Tim

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gdflys
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Re: Fuel Gauge upgrade

Post by gdflys »

I'd try another calibration with the electrical system at 14V versus battery 12.4 ish volts. Might need an electrical power supply or battery charger hooked up to the battery. I haven't installed the senders so not sure what the instructions call for during calibration if anything.
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ajak
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Re: Fuel Gauge upgrade

Post by ajak »

I have the CiES senders in all four tanks and 99% sure I didn't use shielded wire, either. I also have LED nav lights/strobes and aux pumps, and much of the wiring is all run together inside behind the leading edge of the wings. No changes in fuel indications for me with engine on or off.

If it were me, I'd first try to isolate what's causing it. I'd try turning the nav lights, strobes, and aux pumps on and off while powered just by battery, and see if there are any changes in the fuel quantity indication. If there is, that might indicate interference between wires from those systems, which shielded wires might help fix. But they're all low voltage systems, so it seems unlikely, unless there are large loops of wire bundled together somewhere acting like a transformer.

If no change in the above, I'd try powering up with an external regulated power supply, and see if you get the same result. Maybe something like a portable lithium battery jump starter, which should be similar voltage to the alternator but puts out clean DC power. If no change in fuel quantity but with the higher voltage, then that means that voltage difference isn't a factor (it shouldn't be, as the senders are supposed to put out a stable frequency over a pretty wide voltage range). A regular battery charger might not work so well for this, as they're not really designed to directly power stuff and often have a lot of AC frequency component on the output.

I also wonder if it could be caused by an older voltage regulator that is allowing some alternating current from the alternator to leak into the rest of the electrical system and interfering with the frequency output of the senders. Do the indicated quantities change if you run the engine rpm up or down?


drak130 wrote:
Sat Jul 08, 2023 8:38 am
Folks that have done the CiES upgrade, having some issues with the installation.

Have not been able to verify myself as my real job is getting its pound of flesh from me. This is from my A&P (great guy by the way):

-Install went well considering the tight quarters
-Fuel read-outs to a CGR-30
-Calibration went well
-All gauges read accurate full
-With engine running all quantities drop 2gal for the mains and 1.5 gal for the aux
-Turn the alternator off, gauges return to full indications
-A&P called CiES who claimed he should have used shielded wire which is not indicated in the installation instructions.
-The only other electrical components out on the wing are the LED nav lights/strobes and the aux pumps

Before we/he tears it all apart again and accomplishes a complete re-wire does anyone have any suggestions or experience with this issue?

I throw myself on the mercy of the court.

Thanks in advance
Tim
AJ
1983 M-6-235
IO-540W1A5D, 81" Hartzell, 4" ext gear, 31" tires, Atlee exhaust, long wings, VGs, LED ldg/nav/strobes, EDM-900, CiES

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