Hello to the forum,
recently I experienced a remarkably strange behaviour with my Turbo Arrow III.Here's the situation I'm faced with:
Almost immediately after take off and a couple of 100 feet above see level the MP drops suddenly all the way down from 40-41 to 22-24 inches (staying there even with throttle fully open no matter what) while RPM are stable at 2580.During ground run tests the problem is 100% nonexistent and everything run absolutely perfect.Several take off attempts showed exactly the same problem exactly at the same time/altitude after take off.The engine is a GAMI equiped TCM TSIO-360FB3B with no more than 200 hours since OH,I just OH'ed the turbo and the magntetos,I already have my Merlyn wastegate inspected by the factory,flushed both tanks and fuel lines,oil,filters and spark plugs changed (fresh annual) and cyl.compression is at 72-74 for all cylinders.All manifold lines are checked and no leaks were found.Trying to determine a 100% correct Merlyn wastegate opperation (irrelevantly I recently received it back from the factory where it was sent for inspection and evaluation) several test are made including the "vacum test" and the engine ground run test described in Merlyn Products Ref Copy Rpt 18-1 J.Everything was found to be more than perfect but still after all the subsequent take off attempts the same problem is still present.It seems to make no sense at all something like this to be experienced only when airborne and not a single time on the ground no matter how hard we try to reproduce the problem during numerous ground engine runs where the engine bahavies flawlessly every time!
Every mechanic I addressed the problem to, is unable to even think of a possible solution making absolutely no sense out of it.Therefore I decided to address the problem to the forum just in case someone could have a clue or even a general idea about the possible culprit.
Any help will be greatly appreciated!
Many thanks in advance,
Nick.
recently I experienced a remarkably strange behaviour with my Turbo Arrow III.Here's the situation I'm faced with:
Almost immediately after take off and a couple of 100 feet above see level the MP drops suddenly all the way down from 40-41 to 22-24 inches (staying there even with throttle fully open no matter what) while RPM are stable at 2580.During ground run tests the problem is 100% nonexistent and everything run absolutely perfect.Several take off attempts showed exactly the same problem exactly at the same time/altitude after take off.The engine is a GAMI equiped TCM TSIO-360FB3B with no more than 200 hours since OH,I just OH'ed the turbo and the magntetos,I already have my Merlyn wastegate inspected by the factory,flushed both tanks and fuel lines,oil,filters and spark plugs changed (fresh annual) and cyl.compression is at 72-74 for all cylinders.All manifold lines are checked and no leaks were found.Trying to determine a 100% correct Merlyn wastegate opperation (irrelevantly I recently received it back from the factory where it was sent for inspection and evaluation) several test are made including the "vacum test" and the engine ground run test described in Merlyn Products Ref Copy Rpt 18-1 J.Everything was found to be more than perfect but still after all the subsequent take off attempts the same problem is still present.It seems to make no sense at all something like this to be experienced only when airborne and not a single time on the ground no matter how hard we try to reproduce the problem during numerous ground engine runs where the engine bahavies flawlessly every time!
Every mechanic I addressed the problem to, is unable to even think of a possible solution making absolutely no sense out of it.Therefore I decided to address the problem to the forum just in case someone could have a clue or even a general idea about the possible culprit.
Any help will be greatly appreciated!
Many thanks in advance,
Nick.
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