Today's Message Index:
----------------------
1. 07:12 PM - ghost in the engine 2200A (tutuzulu)
2. 08:45 PM - Re: ghost in the engine 2200A (Don Honabach)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | ghost in the engine 2200A |
Hi Listers,
I have an engine problem that has everybody, mechanics, Jabiru personnel, and of
course me, totally bamboozled. Any ideas would be welcome.
Here's a review of the problem so far
Immediately after the annual inspection in March, the engine began running rough
above about 2,650 rpm. It starts with a little roughness, and the longer it
runs above that rpm the rougher it gets, and soon the rpm starts bouncing around
wildly within a range of about 2,500 to 2,750. One of the cylinders will
start cooling down in EGTs and CHTs. Which cylinder it is will change; its nearly
always 2 or 4, sometimes 3, and rarely 1. When the power is reduced below
about 2,650, the cool cylinder warms up and everything runs smoothly.
It seems like after every change (see below), it runs a little bit better for a
little while, but then reverts to the same problem. Its interesting that I can
run it for a while and have the problem be on one cylinder, then shut it down
for 5 minutes and then start it again and have the problem be on another cylinder.
The following have resulted in no change:
L, R, or Both magnetos.
Carb heat On or Off.
Electric fuel pump On or Off.
Replaced rotors, distributor cap, spark plug wires, and sparkplugs.
New carburetor. (The only difference this made was that a couple EGTs ran too
high.)
Inspections that were normal:
Ive removed the carb and looked into the intake manifold but could see no obstructions
or abnormalities.
There was no metal in the oil filter.
All the valve springs appear to have the same resistance when I push on them.
The rocker arms all appear perfectly aligned when in the full up/out position.
I also removed the air intake Scat hose and tried running it with carb intake open
to the engine compartment, with both the old and a new carb. No difference.
I'm grounded and heartbroken.
Anybody got any ideas?
Many thanks,
Bob Miller
--------
Bob Miller
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=309346#309346
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | ghost in the engine 2200A |
I would have sworn you bumped the intake house during the annual as it sounded
like turbulent air going into the carb which would have also made sense considering
the cylinders temps, etc.
I didn't see anything in your message about fuel testing beyond electric fuel pump
on/off. Is it possible the mechanical fuel pump is bad/going bad (I'm assuming
the 2200 has a mechanical fuel pump as my 3300A does?). Might be worth it
to setup a temporary gravity feed setup that goes direct to the carb so you can
bypass all fuel pumps.
Good luck and please share when you find out the cause.
Don Honabach
-----Original Message-----
From: owner-jabiru-list-server@matronics.com [mailto:owner-jabiru-list-server@matronics.com] On Behalf Of tutuzulu
Sent: Wednesday, August 18, 2010 7:12 PM
Subject: Jabiru-List: ghost in the engine 2200A
Hi Listers,
I have an engine problem that has everybody, mechanics, Jabiru personnel, and of
course me, totally bamboozled. Any ideas would be welcome.
Here's a review of the problem so far
Immediately after the annual inspection in March, the engine began running rough
above about 2,650 rpm. It starts with a little roughness, and the longer it
runs above that rpm the rougher it gets, and soon the rpm starts bouncing around
wildly within a range of about 2,500 to 2,750. One of the cylinders will
start cooling down in EGTs and CHTs. Which cylinder it is will change; its nearly
always 2 or 4, sometimes 3, and rarely 1. When the power is reduced below
about 2,650, the cool cylinder warms up and everything runs smoothly.
It seems like after every change (see below), it runs a little bit better for a
little while, but then reverts to the same problem. Its interesting that I can
run it for a while and have the problem be on one cylinder, then shut it down
for 5 minutes and then start it again and have the problem be on another cylinder.
The following have resulted in no change:
L, R, or Both magnetos.
Carb heat On or Off.
Electric fuel pump On or Off.
Replaced rotors, distributor cap, spark plug wires, and sparkplugs.
New carburetor. (The only difference this made was that a couple EGTs ran too
high.)
Inspections that were normal:
Ive removed the carb and looked into the intake manifold but could see no obstructions
or abnormalities.
There was no metal in the oil filter.
All the valve springs appear to have the same resistance when I push on them.
The rocker arms all appear perfectly aligned when in the full up/out position.
I also removed the air intake Scat hose and tried running it with carb intake open
to the engine compartment, with both the old and a new carb. No difference.
I'm grounded and heartbroken.
Anybody got any ideas?
Many thanks,
Bob Miller
--------
Bob Miller
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=309346#309346
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|