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Odd Aztec fuel system behavior

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Joined
Jan 19, 2017
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I was starting my '73 turbo Aztec yesterday and had the oddest thing happen: the left engine started normally. In preparation for starting the right, I flipped the mags on, selected the right boost pump, advanced throttle and mix to full, and watched the fuel flow for indication of fuel delivery. Unlike the left, it never came. Just sat there. I rechecked everything, even shut down the left engine so I could hear the right boost pump. Sounded normal. Subsequent cranking produced nothing. Let the starter cool and cranked again. Again nothing.

I selected the inboard tank. Nothing. I let the pump run a full minute with throttle and mixture advanced full. Nothing. Rechecked everything one more time. No fuel, no start.

On a whim, I selected "Off' on the left (good side) tank, engaged the left electric pump, and opened the crossfeed. ((Now that I review the checklist, I see I did the fuel valves ass-backward. Should have been left tank on, left pump on, right valve off, right pump off.) That's why you use checklists.) To my surprise, after a second or two, the right fuel flow came off the peg. Just barely. The engine started, but barely ran. I couldn't advance the throttle and keep it running. After a few seconds, the engine began to take fuel and I could run it full bore. I then reset the fuel valves, closed the crossfeed, and the right engine kept running just fine. Runup was normal. Left (good side) engine started fine.

After a full-power runup, I did a couple of circuits around the pattern. I spoke to the former owner and he told me he'd had the same thing, once, about ten years ago. After he got the engine running, it ran fine on a subsequent 400 mile trip.

??????????
 

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