Bill,
   Your post is a little hard to follow, but I've had something similar happen before on a couple of occasions and both LNC4P's had the old fuel selector which has been known to let air into the fuel system.  Depressurizing the cabin cleared up the problem on both occasions, and after rebuilding the fuel selector, the problem did not come back.  One of them would surge even with the low boost pump on.  Going to high boost would make the engine run fine too, and switching to the other tank would run better also.   Just an idea of something to at least look at. 

Ron Galbraith

I experienced an engine failure while leveling off at FL220 this afternoon. I have almost 200 hours over 15 months on this 2007 IV-P with the TSIO-550B engine, which has 450TT and 220 STOH. We had been tweaking the baffles and checking the CHT probes by swapping probes 5 with 3 and 2 with 4. We had just seen a great improvement in CHTs with the modifications. I was in the process of climbing to FL220 to ge

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