My latest adventure, or my $3000 hamburger run, or new ways your engine can fail you.

[DaV8or]

Super long story alert!

So... I decided to go up to Red Bluff, CA (KRBL) for lunch one Sunday afternoon. All went well until pulling the power back to enter the traffic pattern. When I pulled back to low MP, the engine ran terribly rough, so I put the throttle back open again and it ran OK again. Tried it a couple of times, same result. As I was in the pattern, I elected to land and sort it out on the ground.

After landing, I pulled off and did a run up. What I found was, the engine ran terrible at run up RPM (about 1800) too. The engine monitor indicated high EGTs on number 2 cylinder. Switching mags did not change a thing. Same high EGT and rough running. So I parked and shut down.

This is why I carry a tool kit I thought to myself. I pulled the cowl and inspected both spark plugs from #2. A tiny amount of debris on the lower one, so I cleaned them as best I could on the ramp and put them back. Visual inspection of the rest of the engine turned up nothing. Ran her up again and no change.

That's it. I'm stuck. Not going to fly it, I can't fix it and everything on the field is closed. Because I took the time to troubleshoot, I missed the 2pm deadline and the resturaunt closed. No burger. The adventure begins.

Fortunately, I was parked in front of the local FBO's maintenance hangar. I called the number on the hangar and found out they open at 8:30 the next morning and gave them a heads up that I would be there, ready to help. Luckily, there are two motels in the area that will come pick you up at the airport and so I spent the night in Red Bluff.

In the morning I met the guys, all great guys and we went to work. First suspicion was ignition, so we tested both mags, the timing, the spark plug wires and the spark plugs to #2. Even tried two brand new plugs. Found nothing wrong. Checked compression and all was right on the money. The chief mechanic didn't trust my fancy engine monitor and so we did an old school test with a spray bottle and a running engine to confim the problem was with #2. The MVP-50 didn't lie.

Pulled the injector and it looked clean. Cleaned it anyways. Nothing helped. Still runs like crap. The senior mechanic doesn't trust the junior mechanic's compression test, so does it again and tries all manor of things to get the cylinder to fail compression. It never fails.

The theory is formulated that it might well be a sticky valve, so we pull the valve cover and get at the exhaust valve. It didn't seem very sticky and the springs were in great shape. We decide to do the rope trick and inspect the stem and the guide. The valve stem shows that it did get hot at some point in it's life, but nothing is a show stopper. It's at this point where they ask me, do you run LOP? I say that I often do and the "uh huh, I thought so looks were given out." I was given the speach about burned up engines etc. I kept my mouth shut on the issue.

The valve guide did show a little scoring, maybe from assembly, or a dirt particle. The opinion of the three mechanics scratching their heads on this one was that the valve guide was too tight, probably from the the time of rebuild and should be resized. The little hone they had did little to change the situation, so it was decided a 1/2" guided reamer was needed. They didn't have one, so in the morning they would go buy one and try it. We were done for the day.

There was no guaranty that the plane would be fixed the next day and I needed to get home, so I called my wife to see if she would pick me up. The answer was hell frikin' no! She was not going to drive 6 hours round trip after work. I needed to find my own damn way home. Called the one and only car rental place in Red Bluff (Enterprise) and they told me the town was busy and they no cars of any kind and neither did the Enterprise in Redding. I called all the car rental agencies in Redding (30 miles away) and found Hertz had a 12 passenger van left and Avis had a Mustang convertible. Mustang it was.

By the way, Avis sucks if you want to get them to help you with a one way rental. They are of no help, you have to make the arrangements yourself with the individual agencies where you want to drop it off. Where I picked it up could not help, so I booked it round trip, besides, the plane might run tomorrow, right?

Wrong. The guide reaming accomplished nothing. No Joy. They also replaced the intake gasket on the intake tube because it was leaking oil, again no change. It was clear this was going to take awhile so the car would have to go back. Oakland International (KOAK) was the only place that would take the car back without and "abandonment" fee of $500. They actually worked with me and credited back the day I didn't use the car. The total ended up being $292.47 plus the gas I put in to get home.

The guys at the shop were stumped, but they kept working the problem. Good spark, good compression, no cracks, no leaks, valves not sticking, clean injector, their thoughts turned to the fuel system. It just so happened that there was a Rockwell Commander 112 in their shop that had suffered a nose gear collapse and was awaiting insurance company OK to tear down the motor. The engine is a very similar IO-360 to what my Mooney has, so they got the idea to work from the cylinder back and they took the flow divider from the Commander and put it on my engine.

Voila! The engine ran smooth again! They opened up my flow divider and found that the #2 port was contaminated with very fine, dark silt that was partially blocking the port. Question was, where was it from and how did it get there? The decision was to send my flow divider, my fuel servo and my injectors to a specialty fuel equipment shop and see if there were any problems with the fuel servo and maybe they could identify the debis and point us in the right direction for the failure.

The Fuel Servo turned up clean as a whistle, so it, the flow divider and the injectors were IRANed and returned. All attention turned to the fuel hose that connects the Fuel Servo and the Flow divider. I was pretty certain it was a new unit. The guys claimed they could see a tear, or some such degredation in it, so a brand new hose was ordered and installed.

So on Sunday, I finally got to bring my bird home. This time my wife was willing to go for a drive. At my request, I told them to leave the upper and side cowling off so I could inspect before flying off.

Good thing I did!! The connection where the new hose connected to the Fuel Servo, was loose. I could turn it with my hand. After the "Oh jeez! I'm so sorries" and all the like, they tightened it up and checked all the other connections. So did I. I then buttoned her her up and paid them. One month later.

Please everybody. Inspect your engines and equipment yourself after a shop works on it. This is the third time I have found potentially hazardous things left undone, or not right.

Final bill was $2730.22. $2250 of that was labor. 30 hours at $75 an hour. They did do a lot of work on it and what can you do? You're sort of hostage and it's not like you can shop around or negotiate. For some strange reason, they printed off a copy of the FAA registration page on my plane and attached it to the bill. I guess it was a warning to me that they knew who I was and where I lived if my check bounced, or I tried to reverse the credit card. It is what it is. Part of the adventure.

Oh, I did get that burger on the day I hung around and helped out. It was OK. Not worth $3000.

[rbridges]

good story. All I can say is wow. Did you pull all your hair out?

[PilotDerek]

Along the same as the ending of your story, I taxied up to fuel and saw some fuel leaking off my front gear door. Not knowing why it was there or how. I parked my plane and took off the left side panel. After looking around I found that I had a leak on my fuel flow meter that was spraying fuel almost onto my exhaust. Had a mech come out to check it and it was finger tight. After taking it off the mechanic who installed it put no sealant on the threads it had been lose since install. I'm extremely lucky I found the leak.

Glad you found the problem and thanks for sharing. I'm pretty sure my wife would tell me the same thing if I ever get stuck somewhere.

[Bennett]

Yes, check after you have work done, be it annuals, or "routine" maintenance. I once had a vacuum pump replaced in Illinois, and when a storm blocked me, and I landed in Nebraska (on the way back to California) we found the nuts holding the pump were just finger tight (if that). After annuals I have had the elevator trim jammed by a flashlight in the tail cone, (discovered after takeoff!), a disconnected remote compass sensor, and after a different annual, a disconnected oxygen hose. Also over the years I have found two screwdrivers, and a set of vice grips in various parts of the aircraft after annuals - and these were "good" shops. Nowadays, I insist that the shop flies the aircraft before I accept the work, and pay the bill.

.

[PTK]

All I can say is that they took you for a ride my friend! Did you ask them why they didn't check the fuel divider before ripping into tbe engine!! This is one example where Savvy and Mike Busch would most likely have saved you a lot of aggravation and some money! Unbelievable! And the audacity to copy the FAA registration and throw it in your face! This after leaving loose connections in the engine!

[Becca]

Ouch, a month??

Any advice on how to say enough-is-enough when you can see a train wreck like this heading for the cliff?

[scottfromiowa]

Dave, you have an awesome attitude. I would not have fared as well (mentally) and would have experienced serious anger management issues on discovery of the failure to tighten the fuel servo connection properly...I would have taken the registration and....I digress...again I say the lengths some people will go for an opportunity to ride in a top drop 'Stang

Glad you are back in the air.

[Cruiser]

_{You must have had tremendous confidence in these guys to let them start reaming valve guides on your engine! I would have stopped before that point and started getting second, third and fourth opinions.}

_{I don't like paying for other's learning experience and when they presented the bill I would have politely asked them to walk me through the charges. When it came to 30 hours of labor the conversation would have gone something like .... OK, you want me to pay for all that labor? How long did it take to R&R the fuel servo? Ok, how long for xx? Well that wasn't the problem. How long for xx? Well that wasn't the problem. You want me to pay for you learning about Lycoming fuel systems? Oh, you already know everything about aircraft fuel systems? Why didn't you check this first then? Oh, your mistake? Ok, how much do you think I should pay for that? Really? Well you know better now right? Sure, I know it takes a lot of time to troubleshoot. Are you smarter now than when we started on this? Well then, how much are you going to credit me for your education?}

[David White]

Dave, you have an awesome attitude. I would not have fared as well (mentally) and would have experienced serious anger management issues on discovery of the failure to tighten the fuel servo connection properly...I would have taken the registration and....I digress...again I say the lengths some people will go for an opportunity to ride in a top drop 'Stang

Glad you are back in the air.

QFT, I had the DG in my 172 replaced and one of the vacuum hoses behind the panel hadn't been stowed properly and was binding on the yolk preventing no more than neutral aft elevator travel. Thank god for run-ups. It wasn't a ma and pa shop either, it was a very well known shop at a Class C airport.

[garytex]

Dave, I wonder if this might have been part of your (and My) eratic fuel flow indications? Does it run smoother now?

[PilotDerek]

My mechanics and I just installed a JPI FS-450 in my Mooney a few months ago. IIRC the directions specifically stated that no sealant or teflon tape was to be used on the fuel fitting threads. You might want to verify that if you installed sealant during the course of your repair.

Jim

I will thanks. I wonder why they would not want you to seal the connection? Maybe a concern that a mech would accidently get some sealant in the line? The line isn't safety wired, without sealant what keeps the line from loosening?

[carusoam]

Mooney Pilots must have tremendous...... Uh, patience!

-a-

[Ron McBride]

I had a mechanic put teflon Tape on my fuel transducer, a year later, we had to remove the fuel controller and have it rebuilt to remove the teflon tape debrii. I had an engine that on takeoff was fine, about 400 feet in the air, it felt like the pistons were swapping holes, do a runup and it was great, fly again it was fine, 2 or 3 flights later, chaos again. We checked everything.

Doing the baby bottle test would have shown a Dave's fuel divider problem.

Ron

[larryb]

So did you ever find the source of contamination? It bothers me that our engines only have a couple fuel screens and not a real fuel filter.

[PilotDerek]

I had a mechanic put teflon Tape on my fuel transducer, a year later, we had to remove the fuel controller and have it rebuilt to remove the teflon tape debrii. I had an engine that on takeoff was fine, about 400 feet in the air, it felt like the pistons were swapping holes, do a runup and it was great, fly again it was fine, 2 or 3 flights later, chaos again. We checked everything.

Doing the baby bottle test would have shown a Dave's fuel divider problem.

Ron

Ok, I gotta ask. The baby bottle test?

[Cruiser]

remove the injectors and place in containers (baby bottles) run the boost pump for xx seconds and measure the fuel flow to each cylinder.

[Marauder]

Ok, I gotta ask. The baby bottle test?

Great way to check for both contaminants and for uniform fuel flow.

[carusoam]

Attempt to find where the contamination came from. Fuel hoses have been rumored to flake.

If filters and screens are still intact, are there any rubber/polymer seals, components or hoses that are aged and downstream of the screen. Fuel pump parts made of polymers?

I would be surprised to see where polymers are used, but wouldn't rule them out either. Getting the bits under a microscope might help identify them. Is it dirt, rubber, plastic etc. Flake, chunk or silt.

Analytical equipment similar to what is used for oil analysis could be telling.

Best regards,

-a-

[RJBrown]

I own a car repair shop, have for over 31 years. My policy is: I charge for the correct repair at the price is would have been if I was perfect. The other day a customer brought in his daughters new to her 185000 mile Xterra. The lifters were very noisy. Customer ask for and got the lifters replaced. Noise was still there. With the rocker assembly off prior to reassembly I had my mechanic crank over the engine so I could see oil come out of the passagway on both heads. Second time apart no oil to where I saw it before. Pulled the heads and found the oil port to the left head plugged with carbon. (CHANGE YOUR OIL) I used a small dril in my fingers to open up the hole then flushed back and forth between both banks before reassembling the vehicle. Lifters paid 5 hours head gaskets paid 12 hours plus some time to clean out ports. Customer paid 13 hours, the lifter labor was fogiven. To charge for "learning" is THEFT dont pay it, that only encourages stupidity.

[RJBrown]

I will thanks. I wonder why they would not want you to seal the connection? Maybe a concern that a mech would accidently get some sealant in the line? The line isn't safety wired, without sealant what keeps the line from loosening?

The threads are not the seal in this application like when tapered threads are used.

In tapered pipe threads sealant is used in most applications. When line are of the flared line fitting type there is a metal to metal seal and sealant of any kind is worthless and teflon tape is hazardous.

The lines in a brake system in cars are this type, never use teflon tape. The lines in car fuel injection systems also use metal to metal contact to seal. If it is not house plumbing dont use teflon tape!!!!

I have seen where idiots have used teflon tape to seal water temp sensors. But wait it insulates the connection and defeats the purpose of the sensor. Any one that would use teflon tape in the situation mentioned simply does not understand what they are doing. There is a difference between a parts changer and a mechanic. Same difference as that between "trainable" and "teachable". A monkey can be trained to repeat motions without knowing why. If you are taught to understand why and how you then can understand what you are doing. Most APs are trained monkeys, hopefully they work under the guidance of an IA that has been taught to understand what is being done.

[DaV8or]

Dave, I wonder if this might have been part of your (and My) eratic fuel flow indications? Does it run smoother now?

Nope. No change there. The only change has been that the bizarre phenomenon that I used to have where the mixture would behave opposite of what it was supposed to do, is gone and it behaves normally now. In the past, whenever I would operate in the LOP region, if I would reverse course on the mixture knob, the engine would continue going in the direction it had been going for a short time and then catch up to where it should be. Example- I would lean out to say, 8.5 gallons an hour, WOT. Maybe the engine runs a little rough, or the power reduction was just to much, so I would turn the mixture clockwise for richer, but instead of getting richer, it would continue to lean, fuel flows would drop to say 7 gallons an hour, the engine would stumble to the point it was about to quit and then eventually it would come around and richen up. It would also do this going the rich direction.

I described this problem to several mechanics, the fuel servo people, folks on the internet and nobody had any idea why it would do this. To this day I have no idea why it did that. I just know that either the cleaning of the flow divider, or the IRAN of the fuel servo seems to have fixed it. So I'm happy about that.

[DaV8or]

Doing the baby bottle test would have shown a Dave's fuel divider problem.

Ron

What's the baby bottle test? I do remember now that they described to me that before they tried swapping the flow divider, they did disconnect the injectors and compared fuel flow of each to each other by pumping into a cup. This is when they realized the #2 was being shorted fuel. Sorry I didn't include that in the narrative above, your baby bottle post jogged my memory and I just now remember them describing this to me over the phone.

[DaV8or]

So did you ever find the source of contamination? It bothers me that our engines only have a couple fuel screens and not a real fuel filter.

Not 100% in my mind, but I guess the theory that fits best is the fuel hose between the fuel servo and the flow divider was defective and either disintegrating, or was assembled badly and there were fraying bits of rubber coming off. Sadly, I wasn't there and so I never got to see for myself the debris in the flow divider. It was described as dark colored and very fine. I do have the old hose, so maybe I'll cut it open and look inside.

[DaV8or]

remove the injectors and place in containers (baby bottles) run the boost pump for xx seconds and measure the fuel flow to each cylinder.

Oh, OK. See above. They did do this. I just forgot about it.

[rocketman]

Has the originator of this post (DaV8or() every thought about writing as a career?