Steve1300 Posted March 28, 2013 Share Posted March 28, 2013 Blade angle 4 degrees, coordinator and prop rigging good, but rpm at 94.5% (accurate tachometer). No obvious shortage of FF. Torque at power does not indicate a problem. How does one go about troubleshooting this? Thanks, Steve Quote Link to comment Share on other sites More sharing options...
Lkuest Posted March 28, 2013 Share Posted March 28, 2013 With everything you've already checked, it sounds like a fuel control. You might swap a fuel control/coordinator combo real quick to verify. It's the fuel control's job to get to HSGI, and it should stay in acceleration mode if it hasn't reached the right RPM yet. Since it doesn't have an abnormally high fuel flow, the fuel control is apparently happy that it thinks it has arrived at HSGI and changed out of accelerating mode. If the valve housing was causing low RPM, the fuel control would be stuck in acceleration mode, and the result would be high torque and fuel flow as the fuel control keeps putting enough fuel to accelerate to on-speed. Quote Link to comment Share on other sites More sharing options...
pjvr99 Posted April 29, 2013 Share Posted April 29, 2013 Nothing wrong with it as far as I can see, its just running right at the bottom of its limit. Only thing i would be concerned about is what is going to happen when you come back from power to low pitch stop, as you normally lose 1 - 1.5% rpm Quote Link to comment Share on other sites More sharing options...
Ronc Posted April 30, 2013 Share Posted April 30, 2013 Steve 1300, As pjvr mentions RPM limits for GI is 94 to 102, what's the problem? Yes, I see that it's on the low side but not out of limits. Do you have any other problems with this engine? Ron Quote Link to comment Share on other sites More sharing options...
Steve1300 Posted April 30, 2013 Author Share Posted April 30, 2013 Steve 1300, As pjvr mentions RPM limits for GI is 94 to 102, what's the problem? Yes, I see that it's on the low side but not out of limits. Do you have any other problems with this engine? Ron If I was flight crew and not a maintainer, I would believe that I don't have a problem. However, I am using an accurate tachometer, and my maintenance limits are 96.3– 99.1. The plane is not here now, so I guess I'll get to play with it later. Quote Link to comment Share on other sites More sharing options...
gmac Posted May 10, 2013 Share Posted May 10, 2013 Concur with Lkuest - If rigging is good, fuel control is bad Quote Link to comment Share on other sites More sharing options...
Steve1300 Posted May 12, 2013 Author Share Posted May 12, 2013 Thanks guys. When it gets back, I'll get a chance to check it out again. Quote Link to comment Share on other sites More sharing options...
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