Iconic Aircraft Aviation Forum

by **Mayfly** » Tue Jul 05, 2011 5:13 pm

She has what is believed to be a fuel problem. No2 wouldn't power up beyond idle. Hopefully she will leave for Yeovilton later in the week.

by **Xplumberlives** » Tue Jul 05, 2011 5:19 pm

Dust in the carburetor?

by **Kermit** » Tue Jul 05, 2011 6:02 pm

Hope it gets fixed promptly, Yeovilton has such a great line up this year, she must take part ! Still, she is 52 so gremlins are to be expected sometimes.
We all have our off days after all

good luck and speedy recovery, whoever flies her, she is still by far the greatest attraction on the airshow scene $\:D/$

by **Minty4371** » Wed Jul 06, 2011 10:55 am

Someone on the other forum has said it is a problem with the ECU. Hope it is easy to fix, and won't involve an engine coming out to get to it.

by **Mayfly** » Wed Jul 06, 2011 4:01 pm

They've bled the system and tried changing a few bits but didn't make any difference so a new CMFS is on it's way from Hinkley

by **Bovril** » Wed Jul 06, 2011 5:36 pm

Minty4371 wrote:Someone on the other forum has said it is a problem with the ECU. Hope it is easy to fix, and won't involve an engine coming out to get to it.

i the fuel system can be changed with engine in place, just a bit fiddly

by **Hihonyr8811** » Wed Jul 06, 2011 9:47 pm

Mum is convinced that 558 just doesn't want to leave Waddington =))

by **Xplumberlives** » Wed Jul 06, 2011 9:59 pm

Hihonyr8811 wrote:Mum is convinced that 558 just doesn't want to leave Waddington

Has she been checking the tealeaves?

by **RLN** » Wed Jul 06, 2011 11:13 pm

Mayfly wrote:They've bled the system and tried changing a few bits but didn't make any difference so a new CMFS is on it's way from Hinkley

??

by **Ramshornvortex** » Thu Jul 07, 2011 8:49 am

RLN wrote:
Mayfly wrote:They've bled the system and tried changing a few bits but didn't make any difference so a new CMFS is on it's way from Hinkley

??

CMFS is the Chassis Mounted Fuel System, which as Bovril says can be removed with the ECU (Engine Change Unit) in situ, although it is more normal to change the whole thing over.

by **RLN** » Thu Jul 07, 2011 9:11 am

Thanks, but being a thicko is it something like the yellow bit in the picture in the link?

http://en.wikipedia.org/wiki/Fuel_control_unit

by **Mayfly** » Thu Jul 07, 2011 9:21 am

Not sure what it looks like but I have seen it described as a very sophisticated carburetor.

by **Sooty655** » Thu Jul 07, 2011 10:37 am

I've looked through our engine inspection pictures from 655, and I haven't found anything particularly helpful. Best I can do is this one.

The CMFS is enclosed in the red polygon. It comprises the two fuel pumps and their associated governors, plus the throttle valve, air fuel ratio control and various other control components.

It is a big lump and not very accessible. The arrow points to a hollow tube which is permanently fitted to the engine, and is used to guide a hoist cable to allow the CMFS to be lowered after it has been disconnected and unbolted from its mountings.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Edit: For those who are interested, this is what the CMFS looks like...............

......and this is what it does.

by **Sploosher** » Thu Jul 07, 2011 11:20 am

Thanks for the pics and description Sooty................................

by **Gully** » Thu Jul 07, 2011 1:51 pm

Lots of pictures of the CMFS's being overhauled at Goodrich on the first restoration DVD.

Methinks Taff and Tall Bloke will be spending a few hours beneath '558 with a long screwdriver 'tuning' the new carburettor / engine set up (as per 3rd restoration DVD) - noisy work!

Gully

by **MOD** » Thu Jul 07, 2011 5:47 pm

Thanks for the diagrams Eric (Mr Olympus)

Thanks also for the heads up Gully. Now searching for my Restoration DVDs after someone has 'tidied' my study.

ibw

by **RLN** » Thu Jul 07, 2011 7:09 pm

Thanks Sooty, I get it now. It uses the fuel as the hydraulic medium to control fuel flow depending on various parameters.

by **Jigsaw** » Thu Jul 07, 2011 7:16 pm

Thanks for the info Sooty, Bovril, RHV etc :ymapplause:

(one reason why this place is so bloody good to frequent).

by **Mayfly** » Thu Jul 07, 2011 7:18 pm

Latest is hopefully engine tests tonight departure tomorrow afternoon - I might just be available to get over to the WAVE if it's after 12....

by **Xplumberlives** » Thu Jul 07, 2011 7:26 pm

Mayfly wrote:Latest is hopefully engine tests tonight departure tomorrow afternoon - I might just be available to get over to the WAVE if it's after 12....

It would have to be after 12, otherwise it wouldn't be the afternoon!