Paul,

I removed the turbo 13b from the Glass Goose and replaced it with a 2005
Renesis.  I was running the engine during fuel mixture adjustments when it
suddenly started to run rough.  The manifold pressure jumped to about 20"
at
idle, naturally the mixture became too rich because the engine controller
was reading the 20" manifold pressure.  Just before that, the manifold
pressure at idle was between 11" and 12".

I cannot find the source of this problem.  I removed the intake manifold
to
check for leaks, the gasket was ok, I replaced it, reinstalled the
manifold,
same problem.  The lowest manifold pressure I can get at idle is between
18"
and 20".  There is a leak somewhere but where?  Or is there another reason
that I am not aware of?

Rino Lacombe
Now, Renesis powered Glass Goose

I did fly about 10 hours last spring (in June) with the turbo 13b.


I have no idea. Can you take a picture of the manifold you are using?
Is the turbo still OK?

Perhaps you have a leak in the hose going to the manifold pressure
gage. Get one of these hand pumps from the auto parts store and check
it out. It is a real handy thing to have around.

Paul Lamar ...No rotor no motor.

Thanks Paul,

I have that vacuum pump,  also have an automotive intake gauge.  I get a
reading of about 10" on the auto gauge and get about 20" on the EM2 gauge
(Tracy's monitor) at idle which should be about the same.

With the vacuum pump I tested each of the hoses that connect to the
manifold.  2 hoses to the engine controller (EC2), it held the vacuum.  I
tested the hose to the fuel pressure regulator, it also held the vacuum.

This is a mistery to me, I ran out of options.

I tested the manifold for leaks and checked the gasket.

Rino

Take the manifold off and bolt it down to a thick peice of plywood
with some inner tube rubber as a gasket. Clamp something over the
throttle body and see if it will hold a vac. Perhaps it is leaking
around the TB shaft. There should be some O-rings in there.
--
Paul Lamar ...No rotor no motor.

I did that on a board of hardwood,  I bolted it with its gasket, no leak
there.  I pluged the injector holes and filled the manifold with water up to
the top of the throttle body.  That is how I found a couple of pin holes in
the weldings, also had a leak at one side of the throttle body shaft,
corrected that.

I will do some more testing today.  I will apply about 11" vacuum to the
engine controller to see how it will react to that but that does not solve
the leak.

Rino

You might be getting some pulsations in the vac signal going to the controller.
It looks like you are tapping off the vac right behind the throttle. Tracy does not
average the intake manifold vac.


Paul Lamar

Rino. Try a vac can to smooth the pulses. I'll be gone for the
next 12 hours.

--
Paul Lamar ...No rotor no motor.

Rino.
Try doing a compression test on the rotors. I had landed after a 1 hr.
flight and the engine would no longer idle. After two weeks of pulling my
hair out looking for intake/mixture problem I did a compression check on my
50 hr. old Atkins rebuild to find the apex seals gone in one of the rotors.
That says something for the Rotary engine, it show no signs of a problem
during the flight, and got me on the ground without incident.
Mark Kirkpatrick
MSK6 20B

Thanks Mark,
I did the compression test.  It reads about 90 psi on every lobe of each
rotors.  That seems to be OK.

Rino


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