---

To: lml@lancaironline.net
Date: Mon, 24 Jun 2013 12:26:53 -0400
From: dico@internetworks.ca
Subject: [LML] Lot of priming recently on engine start (Lancair IVP)

Hi All,

Recently I've noticed that when I start my TSIO500E engine that I have to press/release the primer button probably 50 times after the engine starts.   When I first got the plane a couple years ago I might have to press it 5 or 6 times.

BACKGROUND

I bought the plane almost exactly 2 years ago (July 2011).  I flew it for a few months and then in 2012 (from January to October) we re-did the entire panel as well as all new probes for the engine monitor as well as GAMI injectors.  The plane obviously didn't fly or run during this period.    On our first flight, we made sure that the fuel flow for take off was in that 41-44GPH range.  It took a couple of adjustments to that screw to get the fuel flow set right.   Once we started flying it, the captured engine data was sent to GAMI and after 3 or 4 tries, they said that we had the engine running well (as far as the GAMI's were concerned -- less than 0.5gph spread).   I've just noticed that the #4 CHT /EGT is very low compared the the rest (see graphs taken at 1040 RPM idle).  If I push the power to 1600RPM or better, the CHT/EGT for #4 come up in line with the others.  

STARTING PROCEDURE

In case it makes a difference... I start the plane by pushing everything forward... pressing the primer for 6 or 7 seconds.... pull the mixture all the way out and the power about 1/2" forward.  I turn the key and the engine starts with just a turn or two of the propeller.  Works slick every time.  However after it catches, I have to keep pressing the primer to keep it going.   However, if I put the RPM to about 1300, then the engine will stay running (with any further priming).  The problem is that this overheats the engine.   Two weeks ago I was on the ground for about 30 minutes in 21C weather and a couple of the CHTs got to 380-390.



I was told by a long time mechanic that the Continentals have issues with the engine driven fuel pumps and that since the plane had been sitting a long time that it probably didn't help.  I was going to get the fuel system properly calibrated with the proper equipment but I was told that it would be best if I take the plane out of the hangar and run it at low idle (1000 RPM) for 25-30 minutes to exercise the gaskets/etc for about 3 weeks (every 2nd day).  After that, it would make sense to get the fuel system checked.   After a lot of monkeying around, I can eventually get the engine to idle at 1000RPM, but it takes a few minutes to get it there (certainly not ideal).  I've attached a spreadsheet of my last 25 minute idle session... you can see how at the first the fuel pressure is high, then drops off, then high again (me pushing the primer) and eventually levels off to around 8PSI.

Once flying, the plane sounds good however the CHTs on a couple cylinders get quite hot (400-415 in the climb --- climbing at 300'-400'/minute under 10,000').... the hottest CHT levels off to 380 in cruise at 15000.  The coldest about 290 during the same flight.

I'm open to any and all comments / suggestions / voodoo !

--
Regards,

Dico Reijers


902-629-9911 (T)
888-368-9484 (F)
-- For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html