[Alexaussi]

I’ve been pulling my hair out over this one for too long and reading countless forums without luck. Any extra brainpower would be a great help.

2010 Ducati Multistrada firing only on Vertical cylinder.
Horizontal cyl getting spark and fuel (spark not bright blue but still sparking).
Swapped coils and injectors between cylinders but problem does not follow the parts. Still backfiring when H cyl is connected to injector. Can run on V cyl only.

I originally thought it was the valve timing. Adjusted and timed valves . No change. Gets good compression 180psi on both cyl.

At compression (feel air coming out with my thumb over the spark hole) TDC of H cyl the Tmarks on the cams are the inverted Ts on both cylinders, so it looks like it can’t be 360 degrees out of timing on the H cyl. Right? I bought a timing light and will double check this when it eventually arrives.

I have a second engine I use for troubleshooting as I am in the jungle in a country without a Duc dealer. Put in the other engine that was running fine when I pulled it. No change. Therefore I assume it must be non mechanical.

Swapped ECUs. Nada.
Black box changed. No change.
Swapped plugs. No change.
Swapped coils. No change.
Swapped ignition relay. No change.
Swapped fuel lines. No change.
When I pull out the coil and ground it I get a spark.
When I pull out the injector it is spraying fuel.
Plug on H cyl is wet and smells like gas = not firing correctly and backfires when connected.

Only other thing I can think of is the spark timing is out... but how is that possible if the spark is controlled by the ECU?

Is there anything I haven’t tested?
-2 identically bad ECUs?
-Plug connection bad pins to ecu?
-Bad wiring or earthing??

I’m about ready to buy a Ducati DDS as I have to fix (or cremate) this bitch! As a side note can I buy and use the Ducati DDS 2.0 on this bike?

Any advice GREATLY appreciated to mitigate the helpless lonely midnight solo wrenching sessions.

 

[2004 999s]

any chance you may have crossed the coils?

 

[Alexaussi]

Checked the service manual for correct wiring and they are not crossed.

 

[t-bills]

Check the air pressure sensor for the horizontal cylinder. I don't remember off the top of my head where it is. I've accidentally pulled the vac line off of the vertical cylinder's sensor. It makes that cylinder really rich and could easily be too much fuel to the point you are blowing out the spark.

 

[Alexaussi]

Check the air pressure sensor for the horizontal cylinder. I don't remember off the top of my head where it is. I've accidentally pulled the vac line off of the vertical cylinder's sensor. It makes that cylinder really rich and could easily be too much fuel to the point you are blowing out the spark.

Checked the MAP sensor with Tuneboy throttle balance and both MAPs are working well.

 

[t-bills]

GO back and check the valve timing again, then. I don't remember what position the Ts on the cams should be at, but both cams should be on rest at TDC. The crank pulley has a marker on it that should line up with the case cover marker for TDC for the horizontal cylinder. If you are 360 out (or any other amount out) the valves won't be closed when the crank marker is lined up.

 

[Alexaussi]

GO back and check the valve timing again, then. I don't remember what position the Ts on the cams should be at, but both cams should be on rest at TDC. The crank pulley has a marker on it that should line up with the case cover marker for TDC for the horizontal cylinder. If you are 360 out (or any other amount out) the valves won't be closed when the crank marker is lined up.

Double checked again and yes both valves are closed at TDC with the case markings lined up for the H cyl.

And I did swap the engines and had exactly the same symptoms, even if the engine was running when I pulled it out, so less likely that both engines had their valves out of timing on H cyl.

 

[t-bills]

Yikes. Given the 2 engines situation, and you've swapped the ECU, I've got nothing.

 

[Alexaussi]

Yikes. Given the 2 engines situation, and you've swapped the ECU, I've got nothing.

Damn

 

[Buhgaboo]

Spark plug and wire cut?....if it happened on both motors what didn't get swapped?...I'd check the wires resistance/ohm between the coils and the ECU looking to comparing the two against one another...any disparity well help narrow the focus...wire oxidation?

 

[orionengnr]

If you have swapped engines and having the same result, it is logical to conclude it is something that is not common to both engines.

Did you swap throttle bodies or use the same set? If the latter, injector, TPS or something connected to throttle bodies? Pressure reg is common to both cylinders--if you have enough fuel pressure to fire one injector, the other probably has pressure too. If you have fuel on the plug, cylinder is probably getting enough.

Or something ignition related...whatever was not swapped with the engine is suspect. Did you swap plugs from one cylinder to the other? Sometimes it's the simple things.

Wouldn't it be crazy if you swapped engines to find that you had a bad plug?

Please keep us updated. Someone will give you an idea that will solve your dilemma, and someone else will benefit from this thread sooner or later.

We all love a mystery, but the only thing better is solving a mystery (especially if it's yours).

 

[CRFan1]

Seems to me like you have a wiring issue so I would start there and check the applicable wiring harnesses, etc. Make sure all connections are secure as well....

 

[2004 999s]

may want to check each plug for continuity back to the ecu -eliminate any pin corrosion and test the relay's.

https://andyw-inuk.smugmug.com/Motorcycles/Ducati-Multistrada-1200/Multistrada-MTS1200-diagrams/i-WZNK6FF

 

[Alexaussi]

Ok. So it seems you are all in agreement that it seems to be wiring related.

Yes I put in brand new plugs and a different throttle body.

So I will ohm out all the cylinder specific wires, relays and sensors that go to the ECU and report back once I get home.

Thanks also for the encouraging words. It really helps.

 

[Steve W.]

@Alexaussi

Did you get it sorted out? Very interesting problem.

Cheers Stevo