M20K 231 - 46.5 GPH at 35.8" MP

[av8r14]

Hey guys. First time caller long time reader.

I have a K model that had been down for a while. (Couple Years)

Annual and Engine Overhaul performed a few months ago.  I finally made time to go run it and after an aborted take off I taxied back to the hangar.

During the annual/overhaul I added an EDM-830 engine monitor.

Two Reasons I aborted T/O

1. The FF indicator was intermittent. EDM-830 and the on board FF indicator registered no FF.  When I investigated further, I found that when I push on the on-board FF (original) the display would light up and then the EDM would register.  I suspect a loose connection is the problem.

2. At around 35.8" MP my FF showed 46.5 GPH.  I'm not sure how accurate this is but in normal idle/taxi ops i had to lean about 6-7 turns before the engine ran smoothly.

 

My question is more of a confirmation.  FF at T/O power in a TSIO 360-LB it should be around 24 GPH. Correct?

Do you think it would have been fine to go ahead and run the airplane and just lean manually with the mixture handle?

Other than that, airplane ran strong, responsive throttle, prop, mixture.

I didn't want to T/O with such a rich FF and cause damage.

[Guest]

Way too much fuel.  You need to get it adjusted.

Clarence

[ArtVandelay]

Way too much fuel.  You need to get it adjusted.
Clarence

Wouldn’t you want to verify the FF reading is accurate first? Anyway of doing that with a ground run?

[Guest]

Just now, ArtVandelay said:

Wouldn’t you want to verify the FF reading is accurate first? Anyway of doing that with a ground run?

Yes somewhat, however if I read it correctly, it’s taking 6-7 turns of the mixture control to get it to idle.  Definitely needs attention.

Clarence

[smwash02]

Given what you mention about your fuel flow, I am not sure if I would trust it just yet.

SID97-3G addresses adjusting the fuel flow based on pressures. This article talks about how to do it without the PortaTest referenced in SID97-3G.

Did you get your fuel pump overhauled with the engine? Mine came back exactly where it was supposed to be.

[carusoam]

For perspective...

My310hp IO550 is set up to burn 28-30gph at SL...

How many hp would it have if you were burning 46.5gph?

There are procedures to follow for installing another engine...

It kinda looks like something has been left out, or got skipped...

Proper set-up of the fuel system is a pretty important step...

Impressive fuel flow, if it is getting burned completely...  for an IO720...

Aborting the T/O sounds like a good call...

PP thoughts only, not a mechanic...

 

Best regards,

-a-

[N231BN]

Your engine would not be running if you were actually flowing that much fuel. Was your transducer recently replaced?

The JPI piggybacks off the factory transducer to get it's fuel flow signal but doesn't power it.

[gsxrpilot]

Yeah it sounds like your K factor is off. That has to be set correctly before you can use the JPI FF readout for any reliable information.