Jabiru 3300 starting problem
Posted: Tue Dec 06, 2022 6:46 pm
by builderflyer
My old Jabiru 3300, when bought new, came with an aenemic Bosch starting motor. As the old starter motor began failing it would barely turn over the engine to start even with a battery fully charged. So I recently replaced the starter motor with the upgraded Nippon Denso starter motor that comes as standard equipment on the newer 3300 engines. With the newer starter motor installed, my 3300 turns over much much faster than it ever did before. The problem now is that my engine will not start or even fire for that matter. It’ll just crank and crank and crank and never so much as fire, let alone start.
When replacing the starter motor, I did not have to pull the engine. The only wiring to be done was to run the new starter motor cable between the starter motor and the starter solenoid. Nothing else was disturbed in doing this work. I’ve since verified that there is adequate fuel flow to the Aeroinjector and that there still is a spark at the plugs. I’ve subsequently looked everywhere I can think of and find nothing wrong. Up until the starter motor was changed, this was a good running/flying airplane.
I’ve exchanged emails with Kerry of Sonex and also Jeff Shultz for their input. I’ve also spoke with Nick, the US Jabiru dealer. While all tried to be helpful by making suggestions of where to look, my engine still does not start. So for now, I’ve given up. I don’t know where else to look.
Has anyone else seen a starting problem like this where apparently turning the engine over faster than before contributes to the engine not firing? I’m open to any suggestions from the rest of you as to what the problem may be.
Thanks,
Art,Sonex taildragger #95,Jabiru 3300 #261
Re: Jabiru 3300 starting problem
Posted: Tue Dec 06, 2022 7:41 pm
by daleandee
builderflyer wrote:Has anyone else seen a starting problem like this where apparently turning the engine over faster than before contributes to the engine not firing? I’m open to any suggestions from the rest of you as to what the problem may be.
Hello Art,
I do not have a clue but would suggest that the problem is electrical & not fuel related. I had an auto engine do this to me after replacing the points in the distributor. I cranked it but it would not fire at all. I had left the rotor button out of the distributor.
I know you are not that careless but the point I’m after it that it is likely something very simple that is being overlooked. Does it spit, pop, backfire, or anything along those lines? Can you try a small shot of starter fluid to see if it does anything? If not then you can be sure it is in the electrical/ignition system.
I don’t see how changing a starter would cause this issue but I don’t have a Jabiru …
Hope you resolve it soon!
Re: Jabiru 3300 starting problem
Posted: Wed Dec 07, 2022 2:45 am
by builderflyer
Hi Dale, thanks for your response. To rule out the two independent ignition systems, while cranking, I checked for spark at a spark plug while removed but still connected to the ignition wire and held against the engine. I also used a timing light connected in series with one of the spark plug wires from each of the ignition systems. Both tests showed there to be a spark as expected. I also checked the 0.010" clearance between the flywheel magnets and the electronic ignition modules to verify there had been no change in clearance and there was no change. But you are not alone in your thinking…I will try the starter fluid idea just as soon as I get some.
I know it’s impossible. There is spark, there is fuel, but the engine does not fire when cranked…no sputtering or anything else. And I was flying the airplane up until the time I changed the starter motor. No other part of the wiring, ignition systems or fuel systems was touched while installing the new starter motor.
Art
Re: Jabiru 3300 starting problem
Posted: Wed Dec 07, 2022 10:32 am
by bobc170a
Hi Art,
Bob Ohlson here from Florida with a Sonex 3300, You probably have this already but in case you don’t on mine I have a ground wire
running from the starter to the airframe and with this ground it made a lot of difference in starting mine.
regards, Bob Ohlson
N528RJ Sonex TD 3300.
Re: Jabiru 3300 starting problem
Posted: Wed Dec 07, 2022 10:35 am
by DCASonex
Did you have the leads from distributor to plugs off ? If so, it is very easy to read the diagram showing their correct placement as from the wrong end of the engine.
If using the Bing carburetor and had the controls disconnected, the control to the throttle might be set so that it does not fully close. That prevent s the choke from working. You will have fuel, but not enough.
If still no go, might post the problem on the Jabiru/CAMit forum: main@JabCamit.groups.io | Home
David A.
Re: Jabiru 3300 starting problem
Posted: Wed Dec 07, 2022 10:53 am
by Area 51%
Do they make a left and right turning starter? Does your engine still spin the correct direction?
Re: Jabiru 3300 starting problem
Posted: Wed Dec 07, 2022 11:10 am
by bvolcko38
Extremely dumb question. Is your new starter rotating the correct direction?
Re: Jabiru 3300 starting problem
Posted: Wed Dec 07, 2022 4:22 pm
by builderflyer
Thanks fellows, there is no dumb question in dealing with this problem. The newer starter motor turns the engine in the same direction as before, clockwise when viewed from behind. The only difference is that the newer starter motor required a different adapter to engage the starter clutch because it has a smaller diameter gear with less teeth than the old one. This change to my older engine was the same as Jabiru made to the many engines they produced after mine. Jabiru quickly realized that the original Bosch starter motor included with my engine when new never had enough torque to easily turn the engine for reliable starting.
Regarding the ignition wiring…none of this was disturbed in the process of changing the starter motor. Same for the p leads to the ignition modules. The only wiring to be changed was the cable between the starter motor and the starter solenoid.
Regarding the carburetor…my Sonex has an Aeroinjector and not the Bing. The Aeroinjector had been in tune for the past couple of years prior to changing the starter motor and it wasn’t touched in any way while doing this work.
As a test to better isolate the problem I’m going out to attempt to start the engine using starter fluid right after sending this message.
Thanks again, Art
Re: Jabiru 3300 starting problem
Posted: Wed Dec 07, 2022 9:48 pm
by sonex892.
Sounds like a problem you wouldn’t expect.
If nothing in the ignition has been touched the extra rpm should only enhance the spark. I have had nothing to do with an aerocarb only a bing. With the bing fuel can cause it to be very finnicky and hard to start if there is a problem with things like the choke circuit or clogged idle jet.
The additional rpm I guess would make using your normal start settings a bit leaner. I’d be looking at a bit more fuel you might just need to be a bit richer at start.
DCASonex wrote:Did you have the leads from distributor to plugs off ? If so, it is very easy to read the diagram showing their correct placement as from the wrong end of the engine.
David A.
At least for the hydraulic lifter versions this confusing drawing was rectified long ago. It is now depicted looking from the back of the engine, not looking through the engine from prop end as it was. It doesnt matter what manual was relevant when the engine was built we should all be using the latest manual from the Jabiru Australian website.
Re: Jabiru 3300 starting problem
Posted: Thu Dec 08, 2022 2:26 am
by builderflyer
sonex892. wrote:Sounds like a problem you wouldn’t expect.
The additional rpm I guess would make using your normal start settings a bit leaner. I’d be looking at a bit more fuel you might just need to be a bit richer at start.
This was my very first thought when the engine wouldn’t start. So I enriched the mixture twice with no success before looking elsewhere with no success. Thank you for the suggestion.
Art,Sonex taildragger #95,Jabiru 3300#261/Aeroinjector
Re: Jabiru 3300 starting problem
Posted: Thu Dec 08, 2022 2:36 pm
by dboeshaar
Wow! I’m dying to know how this plays out.
An engine only needs three things to start: Compression, Spark and Air/Fuel
You seem to have checked at least 2 of these.
And brother Murphy is always telling us: “If anything can go wrong, it will” And after 10 years as an auto mechanic, I have often said “I never touched that, I never touched that, I never touched that” and then I see it sitting on the floor.
Please keep us informed!
Re: Jabiru 3300 starting problem
Posted: Thu Dec 08, 2022 3:09 pm
by builderflyer
dboeshaar wrote:Wow! I’m dying to know how this plays out.
An engine only needs three things to start: Compression, Spark and Air/FuelYou seem to have checked at least 2 of these.
And brother Murphy is always telling us: “If anything can go wrong, it will” And after 10 years as an auto mechanic, I have often said “I never touched that, I never touched that, I never touched that” and then I see it sitting on the floor.
Please keep us informed!
Before it didn’t start I hadn’t touched anything but the starter motor and it’s cable to the starter solenoid. By now I have “touched” everything in searching for the problem. Even though the timing is fixed, I have now confirmed that it remains at 25 BTDC. I don’t pretend to be an engine mechanic but I have been able to keep my Jabiru 3300 running for over 17 years and I’ve never experienced this before. Still looking and appreciate any new suggestions.
Art,Sonex taildragger #95,Jabiru 3300 #261/Aeroinjector
Re: Jabiru 3300 starting problem
Posted: Thu Mar 28, 2024 1:58 pm
by builderflyer
This was an old problem that was finally solved when a difficult start issue became a no start issue. The left ignition coil was ultimately found to be completely out of spec. The right ignition coil was also found to be out of spec but still marginally serviceable. The mag drop test prior to the last flight was completely normal and the flight itself was routine until it was time to restart the engine for the trip home.
After a couple days of searching for a reason for a no start condition, i finally thought to check the ignition coils themselves. They had got me started for the last flight made, the mag drop test had been normal prior to departure, the engine operated normally for the flight…how could the coil(s) be bad. But as noted above, they turned out to be the source of the no start problem. Fortunately, I had a spare ignition coil to replace the left one and as soon as it was installed the engine fired right up and ran normally.
Nick, from Jabiru Tennessee, recommends using the Honda ignition coil. So I’ve ordered one from him and will use it to replace the marginal right ignition coil. The no start or difficult start matter appears to be gone…finally.
Art,Sonex taildragger #95,Jabiru 3300 #261
Re: Jabiru 3300 starting problem
Posted: Thu Mar 28, 2024 11:58 pm
by Kai
During my trials and tribulations getting the Jab ignition modules to work as advertised, I found four things of vital importance:
They had to be cooled by blast tubes in flight as suggested in the engine installation manual.
Introduce some sort of openings in the cowling top over the modules to ensure air circulation over them as soon as the engine is stopped after flight.
Always park the plane out of direct sunlight, preferably in shade.
Use only the best coils from reputable sources. While Camit was still in business, theirs were excellent.
My two bits
Kai
Re: Jabiru 3300 starting problem
Posted: Fri Mar 29, 2024 3:50 am
by sonex892.
Kai wrote:
Use only the best coils from reputable sources. While Camit was still in business, theirs were excellent.My two bits
Kai
I used a Chinese one once It didnt fail for at least 2 months. I now use only Honda, I have had to remove and change the coil lead. I’m sure Jabiru and camit did the same.
Too large a gap on the magnetron to magnets will also make Jabiru’s harder to start. It is a very tight space to check this on a 3300 Sonex.
Re: Jabiru 3300 starting problem
Posted: Fri Mar 29, 2024 9:30 am
by builderflyer
Kai wrote:During my trials and tribulations getting the Jab ignition modules to work as advertised, I found four things of vital importance:
They had to be cooled by blast tubes in flight as suggested in the engine installation manual.
Introduce some sort of openings in the cowling top over the modules to ensure air circulation over them as soon as the engine is stopped after flight.
Always park the plane out of direct sunlight, preferably in shade.
Use only the best coils from reputable sources. While Camit was still in business, theirs were excellent.
My two bits
Kai
Kai, all of your suggestions are spot on. Early on I burned out two ignition coils because the blast tubes used were not large enough to do the job. As you know, the ignition coils do not burn out in flight. They burn out immediately after flying because that’s when they are exposed to the highest temperatures. Your idea to vent the cowling above the coils is an excellent one…I’ve just never come up with the best way to accomplish this so I open.up the oil fill door instead.
Art,Sonex taildragger #95,Jabiru 3300 #261
Re: Jabiru 3300 starting problem
Posted: Fri Mar 29, 2024 9:50 am
by builderflyer
sonex892. wrote:[
Too large a gap on the magnetron to magnets will also make Jabiru’s harder to start. It is a very tight space to check this on a 3300 Sonex.
Steve, my 3300 was built before Jabiru decided it would be a good idea to true up the magnets on the flywheel. That is, the magnets on my engine are not all exactly the same distance from the center of rotation. That, obviously, makes it impossible to maintain the recommended 0.010" clearance from each magnet. So I had to first determine which set of magnets were closest to the ignition coils and use them to set the clearance. Otherwise, when setting the clearance using a different set of magnets, physical interference with the closer set of magnets would occur. Not good.
Art,Sonex taildragger #95,Jabiru 3300 #261