Mailing List lml@lancaironline.net Message #66898
From: Robert R Pastusek <rpastusek@htii.com>
Subject: RE: [LML] Teardown and check TSIO550?
Date: Mon, 9 Sep 2013 17:03:54 +0000
To: Lancair Mailing List <lml@lancaironline.net>
Robert,

You did not say how much time you had on your engine, but if it's not yet to recommended overhaul--which you imply by suggesting an inspection rather than an overhaul, AND the temps/oil pressure are normal,  I'd look for the cause of roughness.  The first suspect for me would be the magnetos, and after that, the rest of the ignition system. Then the fuel system. Problems with either will cause variations in the CHT/EGT/TITs, but they might be subtle. The ignition system is more highly loaded/stressed during high power climbs; if the mags, spark plugs or wiring are breaking down under this load, any of these components will cause the engine to run rough, and it should be a "steady" roughness. An in-flight mag check during roughness will isolate this quickly, but be careful. If the engine quits during this check, you need to pull the throttle to idle before turning the mags back to both. Not doing so will cause a very loud bang, and could damage the engine/turbos/exhaust system.

If the engine "surges" rather than exhibits steady roughness, suspect the fuel system. Turning the boost pump on low, if it's not already on, should help isolate a fuel issue. If it is on, try high boost...but you may need to lean the mixture to keep the engine running.

I don't want to discourage you from finding/correcting the problem...and ferrying it around to different shops with a known problem is just not smart! There are things that warrant teardown and inspect/overhaul. What you describe, given that I am not there/don't have specifics, suggests some good local troubleshooting before tearing the engine apart however...

My two cents.

Bob


My engine started to run rough on climb out, cleared up, and ran rough again.  All the inflight temps and flows were completely in line with previous flights.
Ran a new conditional and found nothing amiss.  Compressions good, plugs clean, oil filter had no metallic.  Ferried it to Kelly Aerospace for work on the A/C and de-ice (mice in the wing!) and the 45 minute flight was uneventful.
However when Kelly flight tested the plane it seemed sluggish and it ran rough again.

Thinking about a tear down and inspection but not expecting a complete rebuild.  Anyone recommended who could be within 1 hr or so of central Ohio?


Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster