---------------------------------------------------------- LycomingEngines-List Digest Archive --- Total Messages Posted Mon 10/05/15: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:15 PM - Io540 high power miss or roughness (Jim Stone) 2. 04:01 PM - Re: Io540 high power miss or roughness (Carl Froehlich) ________________________________ Message 1 _____________________________________ Time: 03:15:55 PM PST US From: Jim Stone Subject: LycomingEngines-List: Io540 high power miss or roughness Hi Guys, I had something new happen today in my Rocket. The engine ran rough at high power settings. I rejected the takeoff. Mag and ElectoAir checked normal on ground and engine ran smoothly. I pulled the cowl and verified all spark plug leads, fuel injection lines, air intake tubes, fuel servo and fuel lines were all normal. I suspect it is fuel related because after climbing to altitude when I attempted to lean the engine it ran rough and no cylinder was lean of peak. I recorded the engine instruments for later reference but saw no issues on EGT and CHT graphs. I did not notice the takeoff fuel flow number but can retrieve it from the recording tomorrow if someone could use it. Any ideas of where to start troubleshooting? Jim Stone Louisville Ky 502-235-3599 ________________________________ Message 2 _____________________________________ Time: 04:01:45 PM PST US From: "Carl Froehlich" Subject: RE: LycomingEngines-List: Io540 high power miss or roughness I assume this just started, you did nothing before it started, and you did all the basic timing checks. Sounds fuel related to me as well. Just troubleshot a fuel issue on an IO-360 after talking to Don at AirFlow Performance. He told us to start with a fuel flow test (disconnect the spider fuel lines as each injector and put a shot glass at the end of each line to collect the fuel). Ours was an idle issue with one cylinder going way lean. The flow test (throttle cracked open, mixture at half, boost pump on) showed one cylinder getting half the flow of the others. We sent the spider to Don and he found a piece of junk floating in it. One other check is to lean at fast idle - make sure all the EGTs go up. If they don't you are already LOP at fast idle. As you describe excessively lean condition on all your cylinders I suspect you are having a more basic issue - such as the spider diaphragm not lifting against the spring to open the path for fuel to flow (other possibilities as well). Recommend giving Don a call. Carl -----Original Message----- From: owner-lycomingengines-list-server@matronics.com [mailto:owner-lycomingengines-list-server@matronics.com] On Behalf Of Jim Stone Sent: Monday, October 05, 2015 6:15 PM Subject: LycomingEngines-List: Io540 high power miss or roughness --> Hi Guys, I had something new happen today in my Rocket. The engine ran rough at high power settings. I rejected the takeoff. Mag and ElectoAir checked normal on ground and engine ran smoothly. I pulled the cowl and verified all spark plug leads, fuel injection lines, air intake tubes, fuel servo and fuel lines were all normal. I suspect it is fuel related because after climbing to altitude when I attempted to lean the engine it ran rough and no cylinder was lean of peak. I recorded the engine instruments for later reference but saw no issues on EGT and CHT graphs. I did not notice the takeoff fuel flow number but can retrieve it from the recording tomorrow if someone could use it. Any ideas of where to start troubleshooting? Jim Stone Louisville Ky 502-235-3599 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message lycomingengines-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/LycomingEngines-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/lycomingengines-list Browse Digests http://www.matronics.com/digest/lycomingengines-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.