***** SOLVED**** 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 1200 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. ****** It was 2 bad injectors. One totally bad and one intermittent. ****
Yes ... and I switched the plugs around from the working cyl to the non working cyl and the fault does not follow - indicating it is not a bad plug.
It started when I left the bike sitting over winter. I changed the fuel, fuel filter, injectors and fuel pump even, thinking it was fuel related.
Have you tried checking continuity of loom run including any connectors between coil and (I assume) ECU?
No. Now that is a good idea. I’ve never done that. Any good write ups on how exactly to do that without frying the ECU? But wouldn’t any open circuit prevent me getting a spark at all when I have tested the coil and plug out of the cylinder and still get a spark? ... although come to think of it, it is a little pinkish.
Yes there are, I won’t be able to find quickly but with the wiring loom diagram you could work it out yourself as you can do the test with the ECU plug disconnected. This won’t rule out a continuity problem between the ECU connector and the ECU pins it’s true, but you could start by carefully looking at the pin and relevant connector for signs of light corrosion or discolouration. Had to do the very same myself but on an earlier multi Strada. Somebody else on here could probably put his hands on the relevant ECU connector numbers quicker than me.
Connector pin 1 is coil horizontal, connector pin 26 is coil vertical These pins might also be relevant as they are cylinder sensitive: – Connector pin 37 is signal map sensor vertical Connector pin 46 is signal map sensor horizontal I noticed that there are other sensor connectors that are also cylinder sensitive but will leave it there for now.
Awesome. Yes it’s ECU PIN number 26 for vertical and pin 1 for horizontal coil. Will try that once I get back to my bike. And to test the earths on the coil wires I guess I backprobe the coil plug to -ve on the battery?
Can’t be the MAP sensors as they work fine when I look at the with Tuneboy throttle balance but I will also check the injectors ECU wires number 2 and 27.
Understand that, but try a new plug. I had a similar experience with a customer bike. Rear cylinder not firing. Did all the tests you've done, DDS was clear, swapped components over etc. Fitted a new plug and it worked. Never got to the bottom of it other than a few theories in my head. Only seen it on that one bike, but for the cost of a new plug, it's worth a go if the other tests don't play out.
Does anyone know which circuits they interrupt.... just offering as a train of thought. The only time the 998 let me down was down to the alarm wiring.
Since the plug is wet it does sound like an ignition issue. Does the coil pack properly engage on the plug top ? Also check the lead where it is tie-wrapped to the lower rad mount, and make sure its not rubbed through. I would be buying a diagnostic lead and having a go with melcodiag to have a read of any fault codes, to make sure its not reporting a bad sensor / coil pack ? Then I would check the entire loom for continuity. Just give it a pull about and make sure its not rubbed through anywhere. Possibly even unclip the various bit around the engine. From memory the front coilpack connector is on the front left trelis, so I would start there. I hope you get it sorted, this must be as frustrating as hell.
