Mixture too lean; misfires; 0.7 GAMI spread

[chrixxer]

7 hours ago, Bob_Belville said:

I assume the mechanic has verified that the throttle travel goes to the stop. You should be seeing close to 18 gph FF on take off at sea level. If that's not happening it would increase EGTs as Savvy (probably Paul @kortopates ) pointed out. 

Injectors checked?

Plugs checked for resistance? Champions or Tempest? I know they're nearly new but... 100F drop on MAG check is a little on the high side.

When was the fuel servo last overhauled? If the simple stuff is okay it is a likely culprit. Mechanic should disconnect the throttle linkage and verify the control level moves freely stop to stop. I don't think servos are field serviceable. ICBW. 

My comments are based on personal experience and discussions with @AGL Aviation. Paul/Savvy has forgotten more than I know...

 

 

Throttle goes to the stops (though IIRC the idle stop was adjusted just before I bought it; it was dying on idle check).

Injectors were checked at the last oil change (10 hours ago).

Plugs don't seem to be the problem (see below).

Fuel servo (new) was installed about 6 months / 100 hours ago. (Not field serviceable, AFAIK.)

[chrixxer]

6 hours ago, jaylw314 said:

You do realize the visual tape indicators on the 830 can be changed from the settings menu?  It's annoying, but takes 15 minutes.

 

Not sure what you mean by that?

[chrixxer]

4 hours ago, gsxrpilot said:

I don't see a good run-up mag check on either. Or if there is a good mag check there, you've got some ignition issues. 

Do a nice and slow mag check. Set power to a steady RPM, I use 1500. When you switch off one mag, let it run there for 30 seconds. Then back to both for 30 seconds, then the other 30 seconds. 

Better yet, go fly and do an inflight mag check, nice and slow, just as prescribed in the Savvy Test Profile.

Post the resulting data.

And what @Yetti said, get a different A&P.

There were no obvious indications any of the mag checks were "bad" (no stumbling, no spikes I noticed, RPM drops were within spec)?

1700 is what the book calls for, and what I've always used. I did some longer mag checks today (see below, once I get caught up with these replies, for a narrative of today's diagnostic flight), not quite 30 seconds, but longer than I've been doing.

Also did a 65% power in flight mag check.

Not using the previous A&P anymore, for anything (so many issues), but he was a one-time thing anyway, "nearest port in a storm" when I needed someone local to go rescue the plane from the ramp at the NAS.

 

[chrixxer]

4 hours ago, carusoam said:

how many hours on the plugs, how many on the mags...?

What plugs are in there?

Are the failing plugs all in the low position... they could be getting oil soaked... (visible when plugs get pulled)

Are the failing plugs all in one mag... the mag could be slowly failing... (check To See the mag hasn’t gotten loose)

 

So for next steps... determine which exact two plugs are showing the problem, using the slow ground run-up...

slow... 30 seconds on L, 30 seconds on B, 30seconds on R...  1.5 minutes and the data collection should capture it... based on the graphs we are seeing today...

I use 30 seconds in this case, because my JPI takes multiple seconds to get one reading...  if the JPI is at its highest capture rate of two seconds... this would be better... the usual six second capture rate makes this 30 second wait time kinda necessary....

And yeah... the run-up should be very visible in the JPI graphs... where’d they go? 

PP thoughts only, trying to help Chrix understand what he is seeing under ordinary Mooney conditions on the ground, not a mechanic or CFI....

Best regards,

-a-

Plugs have 78.5 hours on them, installed mid-December. They're Champion REM37BYs.

Mags were IRAN'd by Aero Accessories in October, 100 hours on them.

JPI's capture rate is now faster than 2 seconds (I set to 1 second this morning, per Savvy's guidance, but could have gone even finer).

[chrixxer]

4 hours ago, Oldguy said:

On takeoff on the second graph, your fuel flow is only 12.3 but within 3 minutes, with no logged reduction RPM, it goes up to 12.8 with an accompanying drop in EGT. Do you recall doing anything to increase fuel flow, such as giving it more mixture, when you left Mountain Valley? I interpret the initial FF to be a result of your leaning to accommodate the DA at your departure airport. Since you are climbing out it would seem counter-intuitive to me to enrich the engine, but being a flat-lander, I don't know if any knowledge I have would apply here. I think the biggest concern for me would be if you made no adjustment to the mixture, and the monitor recorded an uncommanded change.

My Savvy report card I just received (IO-360) shows Max Fuel Flow of 17.9 gph to be the 50% and 17.1 gph to be the 25% number so even the max of 16.3 gph on your first graph would be low.

 

I actually departed from Tehachapi (KTSP), not sure why it shows as Mountain Valley, but I digress. I don't recall bumping the mixture control, but with the f*&king quadrant, anything's possible (it was a bit turbulent). And yeah, I was leaned to what appeared to be best power during a full power static run-up (DA was over 5,000').

First graph was a sea level departure (97.8' MSL, KTOA), and 15.8 gph seems to be what I hit.

[jaylw314]

23 minutes ago, chrixxer said:

Not sure what you mean by that?

You mentioned they had not set the horizontal bar indicators to the parameters you had requested on the 830

[chrixxer]

4 hours ago, carusoam said:

Pell City is about 500’ MSL...

So... follow up question...

Chrix where were you located when all this data was taken?  How far above Sea Level was it?  240’ according to the JPI...

Best regards,

-a-

Flight #1 was from Zamperini Field (KTOA, 100' MSL) to Tehachapi (KTSP, ~4000' MSL, DA was in the 5,000'+ range), flown at 8,500' (after leveling off for the SFRA corridor through the LAX Bravo airspace).

Flight #2 was from KTSP back to Torrance, at 7,500'.

Not sure where the JPI is getting 240' from. GPS altitude maybe?

[chrixxer]

4 hours ago, carusoam said:

So Chrixxer’s max FF at 240’ (?) MSL 12.1 and then 12.7 later on... desires an explanation... (great call OG)

Um, no, I was around 15.8 gph departing sea level. There's no way I was at 240' at 12.1 gph (unless I was landing at idle).

[chrixxer]

3 hours ago, Shadrach said:

Continental or Lycoming, the amount of surplus fuel needed to slow the combustion event is the same. Full rich, max power FF should be .55 to .60lbs/hour per horsepower. So a 200hp aero engine on a standard day should require between  (.55*200)/6 and (.60*200)/6 which is 18.3-20gph. Chrixxers numbers on take off appear to be way low and  inconsistent. At sea level he’s getting 12 to 15gph at 2700 RPM. Manifold pressure appears to be low and inconistent as well. Even on a hot day at 100 feet MSL I would expect more than 24 inches. The other Flight shows 29.1 inches and 16.3 gallons an hour, better but still FF is still low.

Again, I think you're confusing the two flights. One was taking off from Tehachapi with a relatively high density altitude (5000'+), and corresponding low MAP (24" sounds about right for a 29.xx" Hg day) and lower fuel flow. The other was from Torrance (sea level, for all intents and purposes), and ~29" / ~16 gph.

[Shadrach]

6 minutes ago, chrixxer said:

I actually departed from Tehachapi (KTSP), not sure why it shows as Mountain Valley, but I digress. I don't recall bumping the mixture control, but with the f*&king quadrant, anything's possible (it was a bit turbulent). And yeah, I was leaned to what appeared to be best power during a full power static run-up (DA was over 5,000').

First graph was a sea level departure (97.8' MSL, KTOA), and 15.8 gph seems to be what I hit.

15.8 is low. Book calls for 15.4 at a DA 7500’.

 

[chrixxer]

13 minutes ago, jaylw314 said:

You mentioned they had not set the horizontal bar indicators to the parameters you had requested on the 830

Oh. Yeah, that was a gripe. I had everything setup the way I wanted it by the next day. More of a "I just paid you thousands of dollars to work on this thing, and you couldn't be bothered to follow the one-page instructions regarding things like GPS<->JPI integration and display customization?!" complaint.

[chrixxer]

I didn't get a chance to fly the SavvyAnalysis Pro Flight Test Profile this morning, there was a low layer keeping me (without filing for IFR, which complicates things) around 1,000' MSL out over the Pacific; I didn't want too far offshore, and the airspace around there can get convoluted. Also had to get back to the office for a client meeting, so I can afford whatever comes next. (Sigh.) I'll try to do it this afternoon/evening. But here's what I've got so far.

Flight: https://www.savvyanalysis.com/flight/3184233/6303f208-abf0-4bb2-85f2-cec502549fbd

1. Logging interval

I changed the RECORD TIME on the JPI to 1 second. (You know what's awesome? The way JPI's documentation isn't updated to reflect changes to the user interface. But I digress.)

2. MAP and OAT adjustment

I checked the MAP setting (-0.5) in the JPI with the engine off, at almost sea level (KTOA elevation is around 100' MSL). The ATIS altimeter was 29.92; the JPI can only be adjusted to the nearest tenth, and was at 29.9. The factory MAP gauge was reading just shy of 30 In. Hg. (In the run-up, I noted the JPI was showing about 12.5" MAP while the factory gauge was showing about 11", but I have no idea how accurate the 50 year old factory instrument is.)

With the engine off, the OAT on the JPI matched the factory gauge sticking out of the window (24°C), in the hangar. With the engine running, however, after being in the run-up for about 5 minutes, the factory instrument matched the ATIS information (15°C) while the JPI OAT was reading 19°C. I adjusted the JPI down to match the factory gauge and ATIS report, and will monitor over the next couple of flights to see how they compare.

Video: https://drive.google.com/open?id=1dOaC9-r-hK3kralLeRu-DhQ6Agdp_tWN

3. Check idle mixture

I followed the Precision Airmotive instructions (15-338e.pdf) for an idle check of the Idle mixture (at 3:45; the earlier one saw my oil temp drop into the red, so I discontinued it until the engine was warmer): Full rich, idles about 770 RPM, at 2 gph. Leaned to 1.3 gph, RPMs climb to about 950. According to the Precision Airmotive manual for the fuel servo, that climb indicates the idle mixture at least is way too *rich*, not too lean.

Video: https://drive.google.com/open?id=19-xi66mWMVI3NQtGL1RWn-fa4Qb43d91

4. Run-Up

No abnormalities I could see vis-a-vis the ignition system check. Starts at 00:10:00. I did it in "Normalized" view on the JPI, and no cylinder / mag combination stands out as being problematic.

Video: https://drive.google.com/open?id=1zUJGTxp_s1wCNmTR-12gDRFdSUBO9yv6

Did another idle check after the "mag" check; basically the same as before, though I had to fight the throttle to get it below 800 RPM and when almost to ICO RPMs rose to over 1,000.

Video: https://drive.google.com/open?id=1QKoUHhsEW9JW0WC8rwmgq_yuKJYvIFMu

5. Take-Off

From sea level on a very standard day (15°C and 29.92" Hg), take-off roll started at 97.8' MSL), 17:20, MAP was 29", RPMs around 2600 (peak 2674), peak EGT was #4 at call it 1400. Fuel flow was about 15.8 gph.

No video (duh).

6. 1000' lean check

After departing TOA and climbing out past TPA (1100'), I made a left turn at the shore and leveled off at 1,000' MSL/AGL, with power set at WOT, 2550 RPM, and pulled back from full rich. 23:10 in the flight record. I'm not sure I did a great job leaning for this quick test, I was more concerned with not popping the LAX Class B, but it looks like I peaked about 1575, so, take-off was 175° ROP. Not ideal. (I want to do a longer test with better conditions, and make sure I actually find peak.)

Video: https://drive.google.com/open?id=1h9CIdzyLtpb1trUEIXoeM0jy5-KP0tyf

7. Horsepower adjustment

I leveled off (around 30:35 - after fighting MAP/RPM for about 3 minutes, have I mentioned how much I miss the power controls from my '66? Hate the quadrant!) about 700' MSL / AGL and set power for 24"/2400 RPM, to get as close to 70% power as possible. (The placarded range on the scimitar prop makes that difficult down low; avoid continuous operations between 2350-2550 above 24" manifold pressure.)

I started off with an HP CONSTANT of 108 on the JPI, and ended with 120, which brought the "% power" display to 69/70. Close enough for now, I'll dial it in more later, but at least it won't be significantly off like it was before.

Video: https://drive.google.com/open?id=1hewwlIhmJqEZiwsww8xuJlaVH-cb81wf

8. Cruise Mag Check

This one also wasn't exactly like I'd want to do it (too low, not at my "normal" cruise settings). 33:35. Did it about 22.5"/2400 RPM at about 9.5 gph, at ~700' MSL/AGL (which should have been right around 65% power, again, I was simultaneously dodging airspace and staying under a cloud layer, etc). Again, nothing sticks out like a sore thumb vis-a-vis the ignition system.

Video: https://drive.google.com/open?id=1K7Lr6jS9oUTM9EiFatmMEFOPTSjohDxy

 

Edited May 21, 2019 by chrixxer

[carusoam]

Wow, Chrix!

you were busy.

Can you bring the client with you to get more time?

Sign of a really good client! 

The really fast data intervals is really helpful to get good data... it is  still glacial compared to what computers are capable of... but data handling starts to get bogged down by the increasingly large files...

Still interested in a good clean run-up...  maybe the next flight will have the data dropped into Savvy as well?

Best regards,

-a-

[Oldguy]

A couple of thoughts based on what the thread covers up to this point:

1. Regardless of the age of the plugs, there have been several reported cases of Champion plugs spiking resistance and being essentially dead or near to it. A check of resistance of each may point to an easy solution if any of them show up with high resistance. This is the reason Tempest has gained so much popularity with some of us.
2. Regarding the FF readings: is there a chance the "K-factor" on your fuel transducer is not the one in the 830? It would tend to also show up as saying you burned 10 gallons but filling up required 13 or so. Just a question.
3. Not sure why your 830 would record your second flight as starting from L94 instead of KTSP. Granted they are only a couple of miles apart, but most GPS units I have seen can get closer than 2 miles. Wiring problem from the GPS? Or bad 830 unit (701 scanner) itself? Appears to be the common item in your entire list of issues. OR
4. With your fuel flow reporting low (with essentially a new fuel delivery system), EGTs reporting high, and a GPS position off by a couple of mies and a few hundred (thousand?) feet, it almost points to a grounding issue - like the one you spent a bunch of time trying to convince your mechanic to fix. JPI says to use a DVM (digital voltmeter) to measure the difference between instrument ground and the engine block ground. If the difference is greater than 0.5 volts with the alternator charging, the ground to the instrument is faulty. (pg. 21 of the install manual)

I really hope you get this resolved with a minimum of additional time because I have followed your travails and know this has been one looooong PITA.

[jaylw314]

41 minutes ago, chrixxer said:

Oh. Yeah, that was a gripe. I had everything setup the way I wanted it by the next day. More of a "I just paid you thousands of dollars to work on this thing, and you couldn't be bothered to follow the one-page instructions regarding things like GPS<->JPI integration and display customization?!" complaint.

Ah, so you did know how to do that, sorry .  My A&P knows me well enough when he installed the 730 to just leave it alone because he knew I was going to screw around with it anyway.

[chrixxer]

11 minutes ago, Oldguy said:

A couple of thoughts based on what the thread covers up to this point:

1. Regardless of the age of the plugs, there have been several reported cases of Champion plugs spiking resistance and being essentially dead or near to it. A check of resistance of each may point to an easy solution if any of them show up with high resistance. This is the reason Tempest has gained so much popularity with some of us.
2. Regarding the FF readings: is there a chance the "K-factor" on your fuel transducer is not the one in the 830? It would tend to also show up as saying you burned 10 gallons but filling up required 13 or so. Just a question.
3. Not sure why your 830 would record your second flight as starting from L94 instead of KTSP. Granted they are only a couple of miles apart, but most GPS units I have seen can get closer than 2 miles. Wiring problem from the GPS? Or bad 830 unit (701 scanner) itself? Appears to be the common item in your entire list of issues. OR
4. With your fuel flow reporting low (with essentially a new fuel delivery system), EGTs reporting high, and a GPS position off by a couple of mies and a few hundred (thousand?) feet, it almost points to a grounding issue - like the one you spent a bunch of time trying to convince your mechanic to fix. JPI says to use a DVM (digital voltmeter) to measure the difference between instrument ground and the engine block ground. If the difference is greater than 0.5 volts with the alternator charging, the ground to the instrument is faulty. (pg. 21 of the install manual)

I really hope you get this resolved with a minimum of additional time because I have followed your travails and know this has been one looooong PITA.

(1) Yeah, I asked for Tempest, but the A&P had Champions on hand, said they were "just as good," and I was about to leave on a long cross-country (TOA to SUS)...

(2) No. My fuel totalizer is basically spot on (within .5 gallons/tank). E.g., the other day the totalizer said I had 16.8 on board; filling to the 50 gallon tabs, I took on 33.1 gallons.

(3) Unlikely. It's usually spot on, too, and I'd think "wiring" or a bad 830 would show up more regularly. If I had to guess, Occam's Razor, I'd say it's more likely the GNS430W hadn't gotten a good fix early enough. There's some interesting terrain around there. And I just checked my ForeFlight track log, and it shows the same track I see in the map view of the JPI data (ForeFlight gets its GPS position data from the FDL-978-XVR, which in turn gets its data from the GNS430W).

(4) The avionics shop that finally did everything I insisted on (swapping in a new factory CHT probe, etc) checked all the voltages with a Fluke and everything was within spec. I watched them do it. And I've never seen more than 15.x on take-off, even when I had the FS-450 (when I installed the -830 I had the transducer and GPS connections moved from the FS-450 (which I had removed) to the EDM).

What I'm starting to think maybe happened ... Back in October, the A&P who was doing the "early annual"/etc following the emergency landing, was having a hard time getting the fuel pressure into the green arc. I know he sent the servo back to Precision Airmotive to be bench-adjusted; maybe they set the fuel flow too low, as part of the attempt to get the fuel pressure below the red line.

[MB65E]

What is the PN of the fuel pump? What’s its take off pressure? 

I remember you had a run around whit what servo you were going to order. I would have the servo bench checked at PCE, Lycon, or RLB accessory. Maybe your new servo was put together on a Friday and not set up correctly. 

How far down are your EGT probes from the  exhaust flange? If they are closer to the flange than 3 inches I’d say you have a normal airplane. Too close to the stack will read high. 

-Matt

[takair]

At a quick glance, EGT 1 seems to respond slightly different than the others.  Have you done the baby jar test to see if the injectors basic flow is even?  Simple test that is very telling.  While out, have the injectors been cleaned, the air screen cleaned?  Are the injectors installed with the correct breather hole orientation (often overlooked, not sure how much, if at all, it impacts performance)?  Are they the same part number injector in all cylinders?  Someone else mentioned, but worth repeating, is the mixture going to the stop on the servo?  Sorry if some of these are repeats.

[carusoam]

Wednesday morning, early...

Looking like we may have reasons to believe...

1) the two rising EGTs are typical of single plug operations in a cylinder...

Spark plugs can still be an issue... the champion variable climbing resistance over time (ohms increase with engine hours) is hard to find using the usual run-up... the inflight mag check has a better test for that...

 

2) The FF at full throttle seems to be considered in the low category...

Double checking the FF data has shown the K-factor to be reliable...

fuel pump, fuel pressure, fuel servo, anything and everything with the word fuel related to it...

got any historical data from flights before Pt Mugu?  Max FF on T/O?

 

3) on the next flight...

collecting data with that ultra fast data collection rate will make the run-up data really nice... it probably takes 15 seconds for the EGTs to settle after each flip of the mag switch... so don’t be in a rush...

In flight mag test will be the most interesting test for spark plug health...

 

Looking forward to the next data drop...

PP thoughts only...

Best regards,

-a-

 

[Shadrach]

8 hours ago, chrixxer said:

I didn't get a chance to fly the SavvyAnalysis Pro Flight Test Profile this morning, there was a low layer keeping me (without filing for IFR, which complicates things) around 1,000' MSL out over the Pacific; I didn't want too far offshore, and the airspace around there can get convoluted. Also had to get back to the office for a client meeting, so I can afford whatever comes next. (Sigh.) I'll try to do it this afternoon/evening. But here's what I've got so far.

Flight: https://www.savvyanalysis.com/flight/3184233/6303f208-abf0-4bb2-85f2-cec502549fbd

1. Logging interval

I changed the RECORD TIME on the JPI to 1 second. (You know what's awesome? The way JPI's documentation isn't updated to reflect changes to the user interface. But I digress.)

2. MAP and OAT adjustment

I checked the MAP setting (-0.5) in the JPI with the engine off, at almost sea level (KTOA elevation is around 100' MSL). The ATIS altimeter was 29.92; the JPI can only be adjusted to the nearest tenth, and was at 29.9. The factory MAP gauge was reading just shy of 30 In. Hg. (In the run-up, I noted the JPI was showing about 12.5" MAP while the factory gauge was showing about 11", but I have no idea how accurate the 50 year old factory instrument is.)

With the engine off, the OAT on the JPI matched the factory gauge sticking out of the window (24°C), in the hangar. With the engine running, however, after being in the run-up for about 5 minutes, the factory instrument matched the ATIS information (15°C) while the JPI OAT was reading 19°C. I adjusted the JPI down to match the factory gauge and ATIS report, and will monitor over the next couple of flights to see how they compare.

Video: https://drive.google.com/open?id=1dOaC9-r-hK3kralLeRu-DhQ6Agdp_tWN

3. Check idle mixture

I followed the Precision Airmotive instructions (15-338e.pdf) for an idle check of the Idle mixture (at 3:45; the earlier one saw my oil temp drop into the red, so I discontinued it until the engine was warmer): Full rich, idles about 770 RPM, at 2 gph. Leaned to 1.3 gph, RPMs climb to about 950. According to the Precision Airmotive manual for the fuel servo, that climb indicates the idle mixture at least is way too *rich*, not too lean.

Video: https://drive.google.com/open?id=19-xi66mWMVI3NQtGL1RWn-fa4Qb43d91

4. Run-Up

No abnormalities I could see vis-a-vis the ignition system check. Starts at 00:10:00. I did it in "Normalized" view on the JPI, and no cylinder / mag combination stands out as being problematic.

Video: https://drive.google.com/open?id=1zUJGTxp_s1wCNmTR-12gDRFdSUBO9yv6

Did another idle check after the "mag" check; basically the same as before, though I had to fight the throttle to get it below 800 RPM and when almost to ICO RPMs rose to over 1,000.

Video: https://drive.google.com/open?id=1QKoUHhsEW9JW0WC8rwmgq_yuKJYvIFMu

5. Take-Off

From sea level on a very standard day (15°C and 29.92" Hg), take-off roll started at 97.8' MSL), 17:20, MAP was 29", RPMs around 2600 (peak 2674), peak EGT was #4 at call it 1400. Fuel flow was about 15.8 gph.

No video (duh).

6. 1000' lean check

After departing TOA and climbing out past TPA (1100'), I made a left turn at the shore and leveled off at 1,000' MSL/AGL, with power set at WOT, 2550 RPM, and pulled back from full rich. 23:10 in the flight record. I'm not sure I did a great job leaning for this quick test, I was more concerned with not popping the LAX Class B, but it looks like I peaked about 1575, so, take-off was 175° ROP. Not ideal. (I want to do a longer test with better conditions, and make sure I actually find peak.)

Video: https://drive.google.com/open?id=1h9CIdzyLtpb1trUEIXoeM0jy5-KP0tyf

7. Horsepower adjustment

I leveled off (around 30:35 - after fighting MAP/RPM for about 3 minutes, have I mentioned how much I miss the power controls from my '66? Hate the quadrant!) about 700' MSL / AGL and set power for 24"/2400 RPM, to get as close to 70% power as possible. (The placarded range on the scimitar prop makes that difficult down low; avoid continuous operations between 2350-2550 above 24" manifold pressure.)

I started off with an HP CONSTANT of 108 on the JPI, and ended with 120, which brought the "% power" display to 69/70. Close enough for now, I'll dial it in more later, but at least it won't be significantly off like it was before.

Video: https://drive.google.com/open?id=1hewwlIhmJqEZiwsww8xuJlaVH-cb81wf

8. Cruise Mag Check

This one also wasn't exactly like I'd want to do it (too low, not at my "normal" cruise settings). 33:35. Did it about 22.5"/2400 RPM at about 9.5 gph, at ~700' MSL/AGL (which should have been right around 65% power, again, I was simultaneously dodging airspace and staying under a cloud layer, etc). Again, nothing sticks out like a sore thumb vis-a-vis the ignition system.

Video: https://drive.google.com/open?id=1K7Lr6jS9oUTM9EiFatmMEFOPTSjohDxy

 

So the idle mixture is totally independent of operational fuel flow. It is entirely possible to have a rich idle mixture and be lean on take off. 

175 ROP at take off isn’t going to cause an immediate problem, but it’s not very kind to your cylinders. If you want to verify your number and it will run LOP,  you could take your time enrichening to peak from the lean side which is kinder than trying from the rich side. 

[chrixxer]

5 hours ago, MB65E said:

What is the PN of the fuel pump? What’s its take off pressure? 

I remember you had a run around whit what servo you were going to order. I would have the servo bench checked at PCE, Lycon, or RLB accessory. Maybe your new servo was put together on a Friday and not set up correctly. 

How far down are your EGT probes from the  exhaust flange? If they are closer to the flange than 3 inches I’d say you have a normal airplane. Too close to the stack will read high. 

-Matt

Fuel pump: Log book entry says LW15473, but I remember a post-it note with something more specific (Aircraft Spruce SKU) I'll see if I can dig out. I haven't watched fuel pressure at take-off to note the exact PSI showing, but it's always solidly right in the middle of the green arc (14-30 PSI). Every other time I've looked at it (run-up, in cruise, etc) it's about 25-26 PSI.

The fuel servo was already sent to Precision Airmotive once:

Cleaned and Flow check injectors. Fuel servo removed and returned for flow bench test by manufacture. [sic] Re-installed fuel servo. Adjusted mixture and idle. Leak checked.

The chronology:

1. Emergency landing at Pt. Mugu
2. Fellow local-to-Pt. Mugu (OXR) Mooney pilot recommended "an A&P with a van" who worked out of CMA. That A&P visited my bird on the ramp at Pt. Mugu and found the piece of ram air door gasket in the fuel servo.
3. I ordered a "rebuilt" (step up from overhauled, about 1/2 the price of brand new) fuel servo and had it shipped to the A&P, who installed it.
4. A&P then found, with the mechanical fuel pump only, it was only showing about 1-2 PSI, and would only go up to 2100 RPM; attempt to go any higher and fuel pressure dropped off almost completely. Worked fine (full RPM, normal green arc pressure) with the electric fuel pump.
5. A&P tried to convince me to fly it to CMA on the electric pump. I respectfully declined, and ordered "the right" pump from Aircraft Spruce and had it delivered to the A&P. (Tempest overhauled LW15473.)
6. When I went to move the plane from Pt. Mugu (the Navy was very gracious but really getting tired of having my plane hanging out with their Hawkeyes) fuel pressure was pegged at the top of the meter (>35 PSI). At first the A&P was like, "it's air in the lines," or whatever, but I refused to accept the plane back until the fuel pressure was in the green arc.
7. I basically gave the A&P a blank check to take care of all of the stuff he'd identified while working on the plane at Pt. Mugu, and to do an early annual (it was due in October, IIRC, this was in July): Mags, p-leads, etc.
8. I think they swapped in yet another fuel pump, and that's the one I need to track down the Post-It note for, and the A&P had an IA working with him (that I didn't even know about until after the fact), who wrote the above italicized logbook entry.

Things that were done during that long annual and maintenance (per logbook entries and the sparse "invoice" I got):

• Performed 50/100 hour annual inspection IAW Lycoming overhaul manual and FAR 43 appendix D.
• Cleaned, inspected, tested, and rotated spark plugs.
• Removed magnetos and sent to Aero Accessories for 500 hour inspection. Reinstalled magnetos P/N 10-163045-3. Timed magnetos to engine. (Aero Accessories: "Repaired and Complies with Bendix 500 Hour Inspection and all AD's. Replaced contacts, felt washers & strips, oil seals, oil slingers, RETS, carbon brushes, recon. dist. block, recharged rotor, retimed and tested." Charged $240x2 for that, $110x2 for labor, and $185 for a coil.)
• Replaced ignition harness with new P/N KA12402.
• Removed fuel servo and sent to Precision. Installed rebuilt servo P/N 2524054-11.
• Replaced fuel pump P/N LW15473.
• Inspected exhaust for leaks, no leaks found.
• Replaced induction filter with new BA6108.
• Drained oil etc (8 quarts W100 + Camguard), no debris in filter, replaced with new P/N CH48110.
• Compressions: 76/80, 76/80, 77/80, 76/80.
• Cleaned engine.
• ADs current to revision 2018-22.
• C/W AD 11-2-04 by inspection of fuel injector lines.
• Performed leak and operational checks on ground run. No defects noted.
• Cleaned fuel screen and gascolator.
• Flow divider clean reseal measure. [sic]

(I also have line items on a hand-scrawled list for "fuel pump gasket," "vacuum pump hose" (x4), etc., and one that doesn't make sense, for "Fuel Pump LW40595," which AFAICT doesn't exist.)

I'll have to measure the EGT probe location next time I have the cowling off...

 

[chrixxer]

5 hours ago, takair said:

At a quick glance, EGT 1 seems to respond slightly different than the others.  Have you done the baby jar test to see if the injectors basic flow is even?  Simple test that is very telling.  While out, have the injectors been cleaned, the air screen cleaned?  Are the injectors installed with the correct breather hole orientation (often overlooked, not sure how much, if at all, it impacts performance)?  Are they the same part number injector in all cylinders?  Someone else mentioned, but worth repeating, is the mixture going to the stop on the servo?  Sorry if some of these are repeats.

Baby jar test?

Injectors were inspected and cleaned 6 months / 100 hours ago. Can revisit, once my A&P has time to come up for air. Mixture is going to the stops on the servo.

[chrixxer]

3 hours ago, carusoam said:

Wednesday morning, early...

Looking like we may have reasons to believe...

1) the two rising EGTs are typical of single plug operations in a cylinder...

Spark plugs can still be an issue... the champion variable climbing resistance over time (ohms increase with engine hours) is hard to find using the usual run-up... the inflight mag check has a better test for that...

 

2) The FF at full throttle seems to be considered in the low category...

Double checking the FF data has shown the K-factor to be reliable...

fuel pump, fuel pressure, fuel servo, anything and everything with the word fuel related to it...

got any historical data from flights before Pt Mugu?  Max FF on T/O?

 

3) on the next flight...

collecting data with that ultra fast data collection rate will make the run-up data really nice... it probably takes 15 seconds for the EGTs to settle after each flip of the mag switch... so don’t be in a rush...

In flight mag test will be the most interesting test for spark plug health...

 

Looking forward to the next data drop...

PP thoughts only...

Best regards,

-a-

 

(1) I did an in-flight mag check at 1 second data capture on the last flight:

Flight: https://www.savvyanalysis.com/flight/3184233/6303f208-abf0-4bb2-85f2-cec502549fbd

This one also wasn't exactly like I'd want to do it (too low, not at my "normal" cruise settings). 33:35. Did it about 22.5"/2400 RPM at about 9.5 gph, at ~700' MSL/AGL (which should have been right around 65% power, again, I was simultaneously dodging airspace and staying under a cloud layer, etc). Again, nothing sticks out like a sore thumb vis-a-vis the ignition system.

Video: https://drive.google.com/open?id=1K7Lr6jS9oUTM9EiFatmMEFOPTSjohDxy

(2) Historical data, not sure, the old EDM-700 and FS-450 didn't have any way to export data (at least, not in this installation), so I definitely don't have, e.g., JPI files pre-Pt. Mugu. I think I had a GoPro running capturing the panel during my first flights, when I picked it up from Ron back in April of last year, let me dig.

(3) See #1 (the in-flight mag check especially had 20 seconds on each mag individually and 20 seconds on "both" between the left and right checks).

 

Link to flight (for some reason the forum is appending extraneous characters to the end of the URL when I linked it above): https://www.savvyanalysis.com/flight/3184233/6303f208-abf0-4bb2-85f2-cec502549fbd (copy and paste if the link doesn't work? Should end in "fbd")

Edited May 22, 2019 by chrixxer

[chrixxer]

Okay, I found some GoPro footage from the RTS flight out of CMA in November. The FS-450 showed 16.4 peak, 16.1-.2ish, fuel flow on take-off out of Camarillo (CMA), field elevation 76.8' (basically the same as my home field, Torrance (TOA)). Full rich, full throttle, full RPM, and within spitting distance of what I saw yesterday morning. So it doesn't appear to be an erroneous reading on the EDM-830. I didn't have the -700 installed, and the -830 hadn't been put in yet, so no temperature data whatsoever, other than the factory CHT.

Pre-Pt. Mugu Footage Found

Okay, I found a recording of a flight in late June 2018, departing from Paso Robles (PRB), field elevation 800', and it was a warm day (AWOS: 200 @ 15, vis 10, sky clear, 25°C, DP 14°C, 29.88, DA 2300'). Fuel flow on the FS-450 peaked about 17.2 gph and mostly settled in between 16.9-17.1 gph for the initial climb out, then as follows:

• 1000' AGL (1800' MSL, DA ~3300'): 16.4 gph
• 2800' MSL: 16.2 gph
• 3800' MSL: 15.8 gph
• 4800' MSL: 15.5 gph
• 5500' MSL: 15.4 gph (leveled off)

(And then I pulled it back to about 12 gph for cruise.)

Same transducers, same K-factor, as currently being used (accurately) with the EDM-830.

So I seem to have lost around 2 gph from "before Pt. Mugu," and it might have been sub-optimum back then, too (book value is ~100% power at 28.4"/2700, 18.6 gph, at sea level; at 2500' DA, that's 27.5/2700 at 18.2 gph. 

Found an early May 2018 after lunch departure from French Valley (F70), field elevation 1349', hot day... Same: 16.9-17.1 gph on departure, on the FS-450.

 

Edited May 22, 2019 by chrixxer
Added details from June 2018 flight and earlier flights.

[carusoam]

In the latest Savvy graph...

EGT1 & CHT1 are not warming up like the others right from start-up...

What happens at 5:00 into the run?  A peak for some reason... but EGT1 is low but bumps up at this time...   EGT4 screams higher,  while other two aren’t moving... what knobs got moved here?

In the flight EGT4 is getting hotter than the others....

EGT1 is staying colder and really falling out the bottom at the end of the flight like it started....

See if you can point out where the mag tests were... time and switch position... because it isn’t super obvious with all the different things going on...

when the prop knob gets pulled...

+1 on the baby jar test...

Something is weird at 5minutes and 15minutes where the EGT4 has unexplained peaks like a plug not behaving...

It would be great to have Paul take a look at this... @kortopates  Savvy graph questions...

I’ll be back tomorrow...

-a-