f1rocket
Well Known Member
I'd like to share a recent problem I ran into on my Rocket that I would have never found until much later if I didn't have a complete engine monitor in my panel. For me, it highlighted one of the reasons I put a full monitor in this airplane, when in the past, I did not. As a point of reference, I'm running a dual GRT EFIS system with a dedicated engine monitor in the lower EFIS display. I have a tuned and balanced fuel injection system so I monitor and use the EGT and CHT readings from every cylinder nearly every single flight.
A couple of weeks ago, I enjoyed a nice luncheon flight into Cincinnati's Lunken field for a $50 hamburger. On the flight back home, I noticed that both the CHT and the EGT for cylinder #1 were running cooler than they normally due. I found this by using the track feature which gives me 120 seconds of running graphical tape of both the EGT and CHT. EGT was down about 70 dF. This was a little odd as my run up and mag check prior to departure were normal. I played with it a little bit on the way home and decided that I had a blockage in my fuel injector. Once home, I cleaned the injector and flew again. Same problem. Next weekend I met by friends for breakfast and we discussed the problem. They suggested a couple of additional tests. I noticed that the temperature loss occurred during rich fuel settings but when I fully leaned the engine, the temperatures rose to their normal setting. Also, I did a mag check at full speed, and the problem became more apparent. The engine ran rough when just on the mags, as opposed to the EI.
Given all the data, my suspicion was the bottom spark plug on the #1 cylinder was not firing consistently. A subsequent check by my mechanic proved that this plug would fire when MAP was low, but when the MAP went up, the plug didn't fire completely. Replaced the plug and the problem was fixed.
Without the monitor, I would have cruised along blissfully until that plug failed completely, and then I would have found it during a ground mag check. I was losing some performance and fuel economy that would have been impossible to detect without the monitor. I've found that my engine monitor, particularly the functions surrounding EGT tracking and peak cylinder temperature, are invaluable to me in order to squeeze maximum performace out of my engine.
A couple of weeks ago, I enjoyed a nice luncheon flight into Cincinnati's Lunken field for a $50 hamburger. On the flight back home, I noticed that both the CHT and the EGT for cylinder #1 were running cooler than they normally due. I found this by using the track feature which gives me 120 seconds of running graphical tape of both the EGT and CHT. EGT was down about 70 dF. This was a little odd as my run up and mag check prior to departure were normal. I played with it a little bit on the way home and decided that I had a blockage in my fuel injector. Once home, I cleaned the injector and flew again. Same problem. Next weekend I met by friends for breakfast and we discussed the problem. They suggested a couple of additional tests. I noticed that the temperature loss occurred during rich fuel settings but when I fully leaned the engine, the temperatures rose to their normal setting. Also, I did a mag check at full speed, and the problem became more apparent. The engine ran rough when just on the mags, as opposed to the EI.
Given all the data, my suspicion was the bottom spark plug on the #1 cylinder was not firing consistently. A subsequent check by my mechanic proved that this plug would fire when MAP was low, but when the MAP went up, the plug didn't fire completely. Replaced the plug and the problem was fixed.
Without the monitor, I would have cruised along blissfully until that plug failed completely, and then I would have found it during a ground mag check. I was losing some performance and fuel economy that would have been impossible to detect without the monitor. I've found that my engine monitor, particularly the functions surrounding EGT tracking and peak cylinder temperature, are invaluable to me in order to squeeze maximum performace out of my engine.
