Chocks

You might consider expanding your search to midbody's with TKS as well. Might give you some additional inventory of great Mooney's to choose from.

On 10/14/2022 at 8:41 PM, Kelpro999 said:

I had the same running condition and found it was slightly bent intake tube clamps at each cylinder intake. The clamps are aluminum and bow around the tube flange & gasket when the fasteners are tightened. The curve is in the machined recess for the tube and easy to miss. Mine was diagnosed at  300hr since lyc factory rebuild.

 

Thank you. I'll check this next. Otherwise, I have exhausted every other possibility I have researched. The "resolution" that I was given for now, was to keep the vacuum pump spooled up to just at 4lbs when it's hot out. That has worked flawlessly thus far.

@carusoam thanks for the heads up on the "" issue. I have corrected that, and hopefully it will help with the search. 

On 10/1/2022 at 7:28 PM, takair said:

It’s kind of hard to see the MAP in the video, but seems to be moving as well….I have seen the MaP lines chafe through or crack on the back side, hard to see, but they can introduce a leak as well…easy thing to check….

Also, be sure your fuel vents are clear….although it seems that would be worse with high power.

That is a good place to look. You're talking about the manifold pressure line through the firewall? If so, I'll have to find where the calibrated hole is and make sure I don't mess with it.

The manifold pressure stays very constant, unless I lean the mixture, then I get the rpm rise and mp drop. 

Still no resolution yet. No intake leaks found after the pressure test. Intake tube donut gaskets are fresh and supple. Replaced the collar gaskets with new just because they tore during tube removal. Issue is resolved when keeping the vacuum pump spooled up to anything above 4 during taxi/idle ops. I received some input from other drivers with the same engine and they all claim that is just a "Mooney Lycoming thing". I'm inclined to believe that, as I have flown that engine more than 200 hours in the last year, and there is no change or progression in the symptoms.

Next will be to make sure I'm not sticking any valves when the engine is hot, double check the rebuilt items (fuel servo and mags) for any failures and probably change from massive plugs to fine wires and see how that goes.

The search continues...

Just as an update, I also found a post from 2018 that was dealing with a very similar issue on a J. I believe that there is a malformed face on the intake tube on cylinder 2. That would explain the level EGT's but the cylinder running hotter and leaner than all the other cylinders even with a balanced fuel flow. 
The soapy water / air hose up the exhaust test showed no leaks. But that was with the engine cold. Also, I'm unsure the fluid test can be done on a hot engine as well. So I'm going to pull the intake for that cylinder and put one of the new oversized gaskets in it, and see what the result is. Will report back with updates.

Link to earlier thread that helped with my issue: 

On 9/13/2022 at 1:54 PM, Shadrach said:

Not very difficult to block the sniffle drain tube to verify that it is not allowing unmetered air into the intake. If the engine runs better, then it's time to pull and soak the valve.

That's right. It actually took longer to get the clamp off of the valve than it was to test. hehe. I actually replaced the valve, the fittings and the tube due to age, and to make sure it wasn't that. 
Good thinking!

9 hours ago, carusoam said:

speaking of cooling…
 

The top back of the dog house has two cooling tubes that point at the mags…

The old generators had a tube of air coming from the front cowl… with a direct connection to the generator…

The fuel pump has a shroud that gets connected somewhere… for cooling…(fuzzy memory only)

Hot days, hot engine, getting fuel to boil is pretty easy…

This is what makes hot starts extra challenging…

PP thoughts only,

 -a-

Yes, I have the two metal tubes that come out of the back. Then I have an additional hole that takes about a 2" scat tube and it runs about a 14" length just open ended down to the fuel pump area. This is a really good area of investigation for me now. Just have to figure out a good process for testing.

I like all of these thoughts so far. I'll start checking fuel lines, connections and such for anything out of order. No leaks, drips or staining anywhere that I can see from the gascolater up to and around the engine. But I will check the lines from the senders into the belly if I get the guts up to pull interior panels. :\ Thanks @47Uand @Sixstring2k et all. 

@PT20JThe sniffle valve and the lines are all new and clamped tighter than a ducks butt. The fuel pressure gauge was changed out recently. The new one seems to vibrate the same as the old. So I just chalked it up to the "check it later" category. Looks like I need to revisit. A note on that though, my fuel level gauges do a very intermittent bounce sometimes, depending on the tank selected. I'll have to ponder that part. Thank you.

@takairI never even thought of that cooling tube. I have a piece of scat tube that comes out of the back of the doghouse and just kind of points in that general direction. That would be interesting to see if there is a cooling issue with that engine driven pump...

Hey @carusoam, yes the vac time does settle out above the 1200 rpm. That is something I or my A&P haven't worked through yet. I'm wondering if there is a crossover leak somewhere that would cause that inappropriate sync at low rpm, but haven't started asking yet.

Got a weird one:

'64 E. IO360a1a. SMOH 150
Had this low rpm stumble before and after an engine overhaul. Worst occurrence in video link at bottom. Stumble creates RPM (100-200) drop and vacuum drop. Fuel pressure / CHT / EGT ok. Totally intermittent, but only happens when engine is hot after a medium-long range flight. Stumble only happens between idle and about 1200rpm. Completely subsides with power add. Only items out of norm are my #2 cyl runs about 40 degrees hotter than the other 3 - with balanced EGT, but recently on landing I'm noticing that #1 and #3 egt seem to drop off at landing idle. All runups, mag checks, and ignition checks ok.

Troubleshooting completed:
Engine overhaul in March 2022  about 150 hour in now.
Overhauled: Fuel Servo, Flow Divider, Slick Mags
New: Spark Plugs (gapped correctly), Plug wires, Boost Pump, Intake Boot, Sniffle Valve and tube
Existing equipment: Gami Injectors/EDM 700 (no Fuel flow)

Testing:
Run boost pump during stumble
Check mags for change per mag
Change mixture settings during
Open and close Ram air
Cover Ram air port completely
Checked intake gaskets and tubes
Checked sniffle valve and line for leaks/loose connections
Checked all metered fuel flows
Checked spark
Checked timing
Adjusted idle cutoff
Adjusted fuel flow
Cleaned air filter
Mag test after landing
Ignition test after landing



If I think of anything else, I'll edit this. Thanks for any help.

Video of worst occurrence:
https://vimeo.com/748591623

Nothing on the radar right now sir. You gonna move yours closer to show off your new AP?

Hey @N201MKTurbo, totally forgot to update you. Gauge worked perfect for what I needed. Thank you!

No rush. I’m having the fuel divider rebuilt anyway. And I doubt I’ll mess with it until after OSH. 
Let me know where to send you money when ready. 

On 5/31/2021 at 6:35 PM, N201MKTurbo said:

No, I bought it. But it didn’t fix my problem. If you need it let me know and I’ll ship it to you for the same price.

It seems to work fine.

I'll take it if you haven't offloaded it yet. Let me know and I'll DM you my info.

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One of the smoothest, and beautiful landings you'll ever have in a short, mid or long body is a no flap landing over the threshold at 90kts.

Now takeoffs in a Mid or long body are best with the appropriate TO flaps. Shorts handle fine with some or none. Loaded or not.

Now that I'm moved into my new hangar, I'm gonna finally pull the gauge next week and check it. So @Shiny moose you still got that combo gauge for sale just in case I need it?

Looks like you got some good response here. The only additional thing that I will add. Is as @jaylw314 eluded to, you don’t need to worry about the “red box” at that atmosphere. That helps when you’re limited in performance precision by the carb. 
 

Just tell everyone you have double ram air.

Ooooh me me!!

Ok following this.

I've got the hand crank step that I would love to automate. Would be interested in either 9v internal or 12v direct to battery connection and I'm good with automated engagement (with indicator) or I can add a toggle switch to my panel.

Looks great! Can't wait to get my hands on one!

26 minutes ago, Sean S said:

Ha, Answered on Facebook! Dewitt Spain is the airport to go to for Downton Memphis.

Yessir! Perfect. Thank you so much

Time to revive this post. The wife and I are going to make a stop over in Memphis next weekend and we'd love to know the local info on best airport, FBO, things to do. ETC. Calling @neilpilotand @Sean S.

56 minutes ago, David Lloyd said:

First of many!  We had a lot of great memories meeting our parents in Greensboro, Sulphur, Carlsbad, Roswell and Albuquerque. A bunch of those trips were centered around Mother's Day.

So my parents are selling all their earthly possessions and buying a motor-coach to travel the country. I can’t wait to get in the airplane and go meet up with them somewhere! How damn cool is this!!?

Made our first of hopefully many trips in 1258X. Had to show my co-owner our new acquisition by flying her to see her mother on Mother’s Day. They both approve!
Just snapped a quick shot this time, but much more media coverage to come!

@Shiny mooseI'm saving your info for now. I'm gonna try one possible solution next week. If that doesn't work, we'll send you some of that digital cashola

On 5/6/2021 at 7:27 AM, MIm20c said:

I’d replace the gauge with cheap used unit. However, this is Mooneyspace so I’ll recommend a G3x with EIS to replace that gauge. 

Soooo, the second I can put the GFC500 in my serial #131 E model, that will absolutely happen!