fuel flow problem

[Amelia]

Arrgggh. If it's not one darn thing it's another. I feel as if I'm playing aeronautical whack-a-mole. The problem du jour is that the fuel flow indicator stopped working. It was first diagnosed as a faulty connection. Then it was the instrument display that needed overhauled. NOW the thought is that I need a new transducer or some such thing, and Mooney wants $1000 for the thing. Dang!  Does anybody know of a used fuel flow tranducer that could be had for cheap?

[Piloto]

I had the same problem. It was caused by fuel deposits and sediments in the transducer. The transducer manufacturer recommended cleaning it with auto carburator cleaner. Sure enough, after one year of having it cleaned never had any more problems. You can check transducer operation by blowing air (by mouth) into the input port and listening to the whirling sound after you stop blowing.  

José

 

[Cruiser]

I have a Hoskins FT-101 w/transducer removed from an  '84J if you need it.

TomK

gkow@cros.net

[mooniac58]

I am also fighting trouble with my fuel pressure transducer.  Initially it seemed to be acting up because the little tubing that I presume was some kind of static air line was all kinked up.  I pulled this intirely and after a couple weeks of working fine it now is acting erratic again...but in a different way.

LASAR said a new transducer was $1200 - which is just insane (I don't blame LASAR, I know this is just a Mooney thing)!

I can get a new JPI EDM-930 for $4400.00 - this will come complete with 4 CHT/EGT probes, fuel pressure, oil pressure, fuel flow, OAT, and a ton more stuff.  While this will set me back considerably more I think I would rather spend money in the upgrade direction instead of just spending it on a rediculously overpriced factory part.

Thoughts?

[alun]

i have a 930 fitted.  very nice bit of kit but am having problems wit the fuel pressure transducer.  jumps about a lot and has read as high as 160psi!  the transducer will be replaced by JPI so maybe its just a faulty probe as the wiring was checked and seemed ok! 

[eaglebkh]

I have the transducer-less fuel flow indicator...

[FlyDave]

Check out the new 730/830 monitors (1/3 down to bottom of page) from JPI - due out in May.

They fit in a 3 1/8 hole and can be rotated to fit appropriately in your panel.

http://www.jpinstruments.com/newproducts.html

[KSMooniac]

Nice find, Dave!  Those look *very* nice, and if they are a plug-n-play upgrade without having to re-plumb the probes then I might jump on that this summer.

[GeorgePerry]

FYI...JPI is taking orders starting 1 April for Mid May delivery.

[Amelia]

Well, it was a nice try. The mechanics installed the rebuilt display at substantial expense,  blew compressed air through the transducer with the desired result, reinstalled all, and it read just fine.... for one whole hour. Now we're back to where we started, with nothing. And for the fourth time in six months, the #4 egt lead for the EI UBG engine monitor is broken. I'm thinkin' I oughta sell this bird and take up knitting, but probably nobody's buying used airplanes.  On the plus side, even though several indicators were busted, the ground speed readout on yesterday's flight home to coastal NC from St. Louis MO worked just fine: 190 to 205kt at 11,000 ft. Whee!

[Amelia]

Oh, dear.  That's not what I really think, but close enough. Now I have watched a mechanic with a multimeter trace every centimeter of the wire from the fuel flow transducer to the fuel flow gauge, checked to make sure the cannon plug works, and yesterday replaced the tranducer itself. On top of having the gauge itself sent away and cleaned and verified a few months ago when this idiocy began. Still no fuel flow, nothing's changed except that my wallet is $2500 lighter than it was before I tried to have it 'fixed.'  One mechanic shrugs and says learn to get along without it, the next assures me solemnly that it's required equipment and I mustn't fly it until it works. I silently scream WELL, FIX THE FREAKIN THING!!!!. And politely ask if he has any better ideas how to accomplish this thing. He admits he doesn't. 

 

Help !! Anybody?

[Amelia]

And, now, in addition to the fuel flow problem that refuses to be fixed, I note that the flight time counter on the ADF has quit-- though the elapsed-time counter works fine, as does most of the rest of that box.  

And the altitude-hold on the autopilot works great. But the heading-hold doesn't. 

She fumes in stupid frustration.

All this stuff involving electrons happening at once - purely unrelated coincidences, part of the joy of owning an airplane,  or is there a single 50-cent fuse somewhere that involves all this disparate stuff,  that has led me down this ridiculous garden path?

[Cruiser]

Have you tried a different indicator? Even if yours has been sent away, cleaned and "verified" it very well could be the source of your frustration.

Check your POH. I really doubt that the fuel flow is a required instrument. Look in the limitations section. Only those items included for the operating limitations, instrument markings, and basic placards necessary for the safe operation of the airplane, its engine, standard systems and standard equipment are required equipment.

If it is listed in Limitations then it must be original equipment or replacement by STC. 

[Rustler]

Amelia--

Having just gone back and read your posts in this thread, I begin to wonder if you've got an electrical problem that is not specific to one instrument. Could you have a ground that is misbehaving? Perhaps a voltage spike now and then? A voltage regulator that's going south? A loose wire somewhere causing a short? It is all just too suspiciously focused on general electrical maladies to be coincidental in my mind, particularly since you're now seeing system-wide goblins.

Your last post sounded like you're beginning to focus on the same thing.

 

 

 

[Amelia]

This morning our local mechanic went over the system one more time, complimented the nice neat job the last mechanic did on installing the presumably new fuel flow transducer, and hooked a jumper cable up to make sure all was properly grounded.  Then we cranked 'er up, and.... nothing. Still. Not even a flicker.  The mechanic who installed the new transducer says it's exceedingly unlikely to be returnable-- just more good money after bad, caveat emptor, and all that. He agrees that the oddball electric malfunctions that don't seem to make sense might by some stretch be somehow be related, but what on earth do you do about that short of replacing every inch of every wire?

Sigh. No idea where to go from here.

[Amelia]

Yeah, owning a Mooney ain't for financial sissies. But NOT owning a Mooney is awful beyond contemplation.

There's no Mooney service center anywhere close to me, (we're so gloriously isolated that even WalMart's 40 minutes away) but I notice there's one a hundred miles from my son's new home. Anybody have any experience with Midwest Mooney M-20 in Flora, IL? I could at least enjoy some grandsons while the shop rips through those boys' inheritance.

 

[Magnum]

Fixing the fuel flow shouldn't be a big problem. There are three cables going to the transducer, power, ground and signal. IMHO the fuel flow transducer from JPI should be the same Mooney uses (at least in my case). The transducer is giving intermittent high (or low) signals to the computer, depending on the rotating speed of the turbine. This should be easy to simulate to test the computer.

But if your avioncs starts to fail, you should have a look at your alternator and voltage regulator. Maybe your getting spikes in the system which destroy all your electronics. I'd get it checked out from a good avionics shop.

I installed a JPI EDM 800 engine monitor, it uses the factory fuel flow transducer and is connected in parallel with the factory fuel computer. This unit was the best investment I made.

Magnus

[Mcstealth]

Quote: JimR

Maybe you can live with it until your annual is due, and then take it to Dugosh or Maxwell or one of the other Mooney gurus for diagnosis and repair?  I can imagine how frustrated you must be.  I'm very sorry, Amelia.

We had a discussion on another thread recently about the relative costs of the 201 versus the 231.  I think that the situation that Amelia is dealing with right now is more illustrative of the true cost of Mooney ownership than are comparisons based upon model designations.  The bottom line is that the more systems you have, the more you will have to maintain.   

[Amelia]

Now, that is some of the finest hospitality I've ever been offered, and I thank you from the bottom of my heart. It's sure tempting- but a mighty long way from coastal NC. We had a splendid trip to TX hill country a few springs ago- and it was unbelievably gorgeous- every Blue Bonnet, Indian Paintbrush, and White Prickly Poppy for miles around in riotously patriotic full bloom. My favorite photo from that trip was a lovely Longhorn, up to its belly in Blue Bonnets, not far up the road from Kerrville. That was Texas in one swell foop! Then, to add fabulous to fantastic, we spent a few days down at Big Bend admiring canyon walls from a canoe. Whoooeee. Amazing! Maybe that'll happen again, who knows? I'll be sure to let you know.