T337c

[rmorris]

I wrote an email to the IA/a&p who recently completed my annual (early October). Below is the thread. Would love others to share their thoughts with me (either on the board or at rmorris@agsi.us).

Thanks.

---------MY ORIGINAL EMAIL TO IA-------------
Sorry for yet another email, but it?s the easiest way for me to communicate given my schedule.



Please drop me a detailed response at your earliest convenience.


I have had my front engine quit on 4 different occasions now. All since the annual/JPI install. On all four occasions, I hit the high boost fuel pump and get the engine back (have to leave the pump on for about (10-30 seconds). The first time was about 8 hours after the annual on take-off in Punta Cana ? very stressful to lose an engine on take-off with not enough runway left to sit it back down). Second time was that same flight about 15 minutes later shortly after leveling off in cruise. Third time was on a flight last week to Florida. Fourth time was today.


After the first two times (same flight), I thought it must just be something in the gas we took on in Punta Cana. But obviously that gas is long since gone. Again, in all four instances I simply hit the boost pump and got the engine back.



Someone on the DR trip (after hearing about the loss of engine on take-off) mentioned fuel filters ? saying they were cheap and easy to replace. Also of interest was the recent install of the JPI fuel flow meters.



So my basic questions are:

1) Does my Skymaster take fuel filters? If so, how much for the filters and replacement?

2) Any chance the JPI fuel flow meter itself, or something done on the install, could be causing this symptom?

3) Any other ideas on possible causes?
--------IA RESPONSE----------------
Subject: Re: N2475S T337C

1)Fuel Screens that were cleaned @ Annual

2)Most likely not as transducers are mounted in line

3)Water, Fuel pump, fuel selector valve, trash in tank,fuel vents are all possible.

----------MY RESPONSE TO HIS RESPONSE--------------
1) Obviously you would have noted any issues when you cleaned them, but any vlue in replacing them? What is the cost in time/labor to replace them?

2) Them being in-line is exactly what makes me think they might be involved. In other words, maybe turning on the boost pumps causes enough pressure to ?free-up? whatever is binding. Again, if I?m off-base just tell me ? trying to explore options.

3) I would think water would show up in sumping, or at least be done after 1 or two incidents. Please let me know your thoughts on ability to t-shoot a transient problem like this (ie what kind f things would you do on the fuel pump, selector valve, vents, etc) and how much in time do you think it might take?not looking for an exact quote to hold you to bu rather trying to understand the possible troubleshooting process and anticipated costs/timing.


----------------SO FAR NO ADDL INFO FROM HIM---------------
________
MEXICO CITY HOTEL

[WebMaster]

Does the engine completely shutdown, or just slow up?
You do not state how much time you had in between the first failure, and the one yesterday. Had you flown the airplane much in that time frame?
Diagnosing and troubleshooting intermittent problems is most likely time and materials, there is no probable estimate.
It would be logical to suspect the JPI sensors, unless you have flow it a lot, more than 25 hours. Are you seeing higher egt's, cylinder head temps, just before failure? If so, that would indicate a leaning condition. However, if it just shuts down, it is a different problem. Some obstruction to the fuel line, completely blocking the fuel flow

[rmorris]

Larry,
The fuel flow drops precipitously and the engine shuts down. I did not notice temps rising, it seems like they were falling with the fuel flow.

Got plane back early October. The first event was a little over a week and 15 hrs later. The second event was the same flight about 15 mins later. 3rd event was about another 15 hrs later (a week and half or so). Last event was about 10 hrs later (about a week or so from #3).

I understand it will be t&m. Just trying to get ideas before getting into a big guessing game with a lot of unneeded replacements.
________
Yamaha yp400 majesty specifications

[skymstr02]

The airplane really doesn't have fuel filters, they are just screens. There is no added value in replacing them. Replacing the "O" rings on the gascolators would be a greater benefit, as air could be sucked in around the seals and the seals may not show external leakage.

What are the fuel flow indications just prior to the engine problems?

[rmorris]

Originally Posted by skymstr02

The airplane really doesn't have fuel filters, they are just screens. There is no added value in replacing them. Replacing the "O" rings on the gascolators would be a greater benefit, as air could be sucked in around the seals and the seals may not show external leakage.

What are the fuel flow indications just prior to the engine problems?

Near as I can tell, because it happens pretty quick and unexpected, is that fuel flow indication drops rapidly just prior to the engine dying.

Are the gascolators the large spider type thing at the top of the engine? I'm sure the IA will know, but I'm just trying to visualize the difficulty and costs involved in just swapping out the o-rings.
________
Cheap Airsoft Bbs

[rick bell]

maybe sucking air - fuel pump - fuel strainer "o" rings.
if it is sucking air and you hit the boost it will drive alot more fuel masking the air/leaning process.

[skymstr02]

Originally Posted by rmorris

Are the gascolators the large spider type thing at the top of the engine? I'm sure the IA will know, but I'm just trying to visualize the difficulty and costs involved in just swapping out the o-rings.

The front engine gascolator is in the nose wheel well, on the left side, and the rear engine is on the rear firewall on the right side. There are a total of three "O" rings per gascolator.

[tropical]

If you are truly concerned about the problem why not take it to a shop and have it fixed? There's really no way to troubleshoot and find the problem via email or a newsgroup.

Your mechanic is correct, it could be one or more different items.

[rmorris]

Originally Posted by tropical

If you are truly concerned about the problem why not take it to a shop and have it fixed? There's really no way to troubleshoot and find the problem via email or a newsgroup.

Your mechanic is correct, it could be one or more different items.

Why be a member of this board if you have this view?

Clearly there is great value to getting information from others before, during, and after working with anything (plane or otherwise).

Might as well just say, 'take our checkbook and plane and drop them both off - they'll both get fixed for you'.

I take great pride in getting to know my plane and it's systems. I don't try to fix it myself, for both legal and practical reasons, but it helps to get educated. I then try to share my experiences, where applicable, with others.

I appreciate that you took the time to post a response, just wished it had more than 'go get it fixed and leave us alone' as the theme.
________
HONDA VF750S

[tropical]

Originally Posted by rmorris

I appreciate that you took the time to post a response, just wished it had more than 'go get it fixed and leave us alone' as the theme.

I think many here have offered some good advice. But that doesn't fix your problem. No matter what's offered here it's still going to take a mechanic time to troubleshoot the issue. When I was working on airplanes and helicopters I would have owners start off with "I read on the internet...." and then proceed to tell me how to fix the aircraft, whether it was correct or not.

A safety of flight issue should be left to a professional to fix correctly.