was the physical position of the throttle a little more forward than what is
normal for 1000rpm? you did say you had to pull it back quite a bit when it
"roared".... do piston engines really roar?

sounds like something was keeping the engine from running normally when
first started and it took some throttle to get it to idle at 1000rpm... was
it idling rough at what you had set? could have been injectors.. would not
think that would clear that fast and evenly.. could have been "bad gas" in
the line that worked it's way through.. but that too I would think to cause
the engine to "sputter" and not idle

If it does it again... after sitting a few days.. let it sit a few more and
have the A&P with you when you start it... guarantee it won't do it in front
of the mech.

BT

"O. Sami Saydjari" wrote in message
...
Today, after I started by Turbo Arrow III (TCM TSIO-360-FB), I set
throttle to 1000 RPM (as normal). The engine sound a little "funny".
About 60 seconds later, the engine roared to 1700 RPM on its own and I
had to pull the throttle back quite a bit to get back to 1000 RPM.
Run-ups, later on, seemed fine. Has anyone experienced this? Can
anyone explain what might have happened? Clogged injectors maybe?

-Sami
N2057M, Piper Turbo Arrow III