Toobuilder
Well Known Member
Took a very short hop this am with my bride to check out the results of a small local brushfire. Cruising sedately along at 22 squared and lean we approached our airport for landing. Still out about 2 miles, the engine went rough and #4 EGT dropped out on the way to ambient temp. In light of the recent ignition issues I have been though, that was my first thought. Quick mag check showed exactly the same behavior on both ignitions, so that ruled out spark as the issue. That only leaves fuel and air... Since the other cylinders are still going strong, "air" seems unlikely as a cause. So that leaves fuel. With fuel injection and all other indications normal, a blocked nozzle pops into my mind - not a huge deal...
...Then I smell the raw fuel! I'm suddenly not interested in troubleshooting any more and just want on the ground ASAP. Fortunately, I'm on top of the pattern and simply chop the power, bleed off some speed with some s turns and set myself up for an uneventful landing.
Minutes later I have the cowl off and sure enough, #4 injector line is broken right at the nozzle and dumping fuel right on cylinder head near the spark plug boot. Good thing I didn't go full rich! Anyway, it's an odd failure in the respect that the line broke INSIDE the nozzle ferrule and the silver solder separated cleanly at the joint. Hard to inspect for THAT failure mode!
All in all it was a non event, but I thank God this this didn't happen at 8500 feet over the open desert!
...Then I smell the raw fuel! I'm suddenly not interested in troubleshooting any more and just want on the ground ASAP. Fortunately, I'm on top of the pattern and simply chop the power, bleed off some speed with some s turns and set myself up for an uneventful landing.
Minutes later I have the cowl off and sure enough, #4 injector line is broken right at the nozzle and dumping fuel right on cylinder head near the spark plug boot. Good thing I didn't go full rich! Anyway, it's an odd failure in the respect that the line broke INSIDE the nozzle ferrule and the silver solder separated cleanly at the joint. Hard to inspect for THAT failure mode!
All in all it was a non event, but I thank God this this didn't happen at 8500 feet over the open desert!
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