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

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
>

BTIZ wrote:

> was the physical position of the throttle a little more forward than what is
> normal for 1000rpm?

Yes.

>
> 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?

Not rough in the sense of vibrating unusally. It just sounded a little,
ih, weak...hard to describe.

> 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
>

"O. Sami Saydjari" > wrote in news:106n16goaaj8933
@corp.supernews.com:

> 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.

Could be a lot of things, but I'm guessing it's as simple as a couple of
plugs (on different cylinders) being damp, or maybe a couple of lifters
slow to pump up. Mine tends to do the same thing, although usually only
for about 10 seconds.

Right now, I wouldn't worry about it. If you start having problems with
the runup, or other indications of less than full power available - OR it
starts to take longer and longer to "settle down" then it needs to be
checked. But at the moment it doesn't sound (purely personal opinion here)
like anything of concern.

-----------------------------------------------
James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
-----------------------------------------------

Is there a chance that the throttle cable is loose somewhere allowing it
to buckle then release?
That could really suck if you were powered down on final and needed to
do a go-around!

Just a thought.

Dave

James M. Knox wrote:
> "O. Sami Saydjari" > wrote in news:106n16goaaj8933
> @corp.supernews.com:
>
>
>>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.
>
>
> Could be a lot of things, but I'm guessing it's as simple as a couple of
> plugs (on different cylinders) being damp, or maybe a couple of lifters
> slow to pump up. Mine tends to do the same thing, although usually only
> for about 10 seconds.
>
> Right now, I wouldn't worry about it. If you start having problems with
> the runup, or other indications of less than full power available - OR it
> starts to take longer and longer to "settle down" then it needs to be
> checked. But at the moment it doesn't sound (purely personal opinion here)
> like anything of concern.
>
> -----------------------------------------------
> James M. Knox
> TriSoft ph 512-385-0316
> 1109-A Shady Lane fax 512-366-4331
> Austin, Tx 78721
> -----------------------------------------------

interesting thought..

worth a check..

BT

"dave" > wrote in message
news:R14bc.57542$K91.139268@attbi_s02...
> Is there a chance that the throttle cable is loose somewhere allowing it
> to buckle then release?
> That could really suck if you were powered down on final and needed to
> do a go-around!
>
> Just a thought.
>
> Dave
>
> James M. Knox wrote:
> > "O. Sami Saydjari" > wrote in news:106n16goaaj8933
> > @corp.supernews.com:
> >
> >
> >>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.
> >
> >
> > Could be a lot of things, but I'm guessing it's as simple as a couple of
> > plugs (on different cylinders) being damp, or maybe a couple of lifters
> > slow to pump up. Mine tends to do the same thing, although usually only
> > for about 10 seconds.
> >
> > Right now, I wouldn't worry about it. If you start having problems with
> > the runup, or other indications of less than full power available - OR
it
> > starts to take longer and longer to "settle down" then it needs to be
> > checked. But at the moment it doesn't sound (purely personal opinion
here)
> > like anything of concern.
> >
> > -----------------------------------------------
> > James M. Knox
> > TriSoft ph 512-385-0316
> > 1109-A Shady Lane fax 512-366-4331
> > Austin, Tx 78721
> > -----------------------------------------------
>

Sami
my t-arrow, I will initially set it to 1000 rpm to warm up, but as it
warms up it only increases RPM about 1000-1500 rpm. Never had it go to
1700 rpm.


"O. Sami Saydjari" wrote:

> 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