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Sky,
On takeoff Friday morning from the unpaved strip on the island the MP on the front engine only came up to 30" and never exceeded that. The rear ran up to redline and then backed off to 37" which is what it always does. So does the front when the turbo is working. MP dropped on the front as I climbed out but would hold at 27" at FL 180 with full throttle. Fuel flow during takeoff was 104 on the front, 140 on the rear.
Oil temps were above 100 at takeoff (heck, the ambient air was at 95!). I can't remember what the RPM was but it was above 2500 as I remember pulling it back to 2500 along with the rear.
While in cruise the MP would slowly cycle up and down by about 3" and the wow-wow would come and go. It's just impossible to keep the engines in sync. The rear would hold rock steady at 27" but the RPM would fluctuate which just drives me crazy.
When later taking off from Houston Hobby the front spooled up to redline, then past redline and pegged! I had to pull the throttle back to get it below redline then pushed the throttle full forward again and it held at 37" during takeoff. However, while in cruise it still runs up and down by about 3".
So tomorrow I'll be having another conversation with my mechanic but I assume that whatever piece of dirt or carbon that had plugged it up in Mexico worked it's way out by the time I was leaving Houston so there's probably nothing for the mechanic to do. But I don't understand why it blew completely past redline nor what is causing the up and down in MP while in cruise. And 27" is the maximum I can get out of it above 17,000. The turbo is brand new as the old one burned up during an unexpected engine shutdown during a missed approach two months ago and I've installed a new controller as well. But nothing has changed regarding performance even with the new equipment. Sometimes it works and sometimes it doesn't and it never holds steady no matter what.
I'm about 150 hours past TBO on the front engine and even though it's got good compression and isn't making metal I'm beginning to think I should just scrap it and put in a new one. I'm about out of ideas on how to fix the front turbo problem. And I have no idea why the rear prop won't hold a steady RPM. That engine still has 300 hours to go before TBO and everything works ok except for the RPM fluctuation. At least it gives me something to do while flying long legs across the Gulf of Mexico!
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