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Discussion Starter · #1 ·
So i went to start the bike today after doing winter maintenance and the vertical cylinder is not firing. I pulled the plug out and checked for spark which it is and I also sniffed the injector for fuel, which it did. Next I checked for trouble codes and get a P0351. I believe this indicates an ignition coil problem. Bike has new NGK MAR10A-J plugs.
I didn't have time to swap coils and plugs to see if the problm follows. I'm just doing research now to see what else it may be.

I'm just curious as to why I'm getting an ignition coil code, yet when i pull the plug and crank it over, I see spark. Is it possible it's just a weak coil?

Any other suggestions while I search?
 

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I got this error during my round and round with the wife's 848.

It ended up that the ECU had been corrupted. I replaced it and all was right. Basically the fueling or timing map got buggered and it would mis occasionally resulting in a chug between 5-6k rpm. Then the codes would reflect a PO351 when I pulled them.

It could also be a bad ground or faulty coil that is intermittent.
 

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Discussion Starter · #3 ·
I got this error during my round and round with the wife's 848.

It ended up that the ECU had been corrupted. I replaced it and all was right. Basically the fueling or timing map got buggered and it would mis occasionally resulting in a chug between 5-6k rpm. Then the codes would reflect a PO351 when I pulled them.

It could also be a bad ground or faulty coil that is intermittent.
Hope it's not the ECU. DP ECU. I did remove the ECU etc to clean the battery box and put some heat shield on the back. How does an ECU get corrupted? My bike just won't hold an idle and the vertical cylinder is cold.

I'm hoping it's a weak ground. I'll have to check my grounding again. I put in a new antigravity 16 cell battery along with the motolectric wiring kit. Motor seems to turn over slower than it should.
 

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I honestly have no idea how the maps in the DP ECU gets corrupted but that's what mine was as well.

Do you have a full system or slip on? If it's a slip on did you by pass your servo?
 

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Discussion Starter · #5 ·
I honestly have no idea how the maps in the DP ECU gets corrupted but that's what mine was as well.

Do you have a full system or slip on? If it's a slip on did you by pass your servo?
it's a full system. It ran fine last season.

I think i'll check my engine ground again too. The engine is turning over slower than it should given the battery and wiring upgrade. Voltage at the battery is 13.5v but voltage on the dash is 12.5-12.8 Something isn't right there.
 

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It;s gotta be something simple because you had it running last year fine. Double check your work, electrical is in theory simple a point A and a point B. just have to painstakingly go through each wires route and condition.
You'll find it.
 

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Discussion Starter · #7 ·
It;s gotta be something simple because you had it running last year fine. Double check your work, electrical is in theory simple a point A and a point B. just have to painstakingly go through each wires route and condition.
You'll find it.
I have a strong suspicion its a grounding issue.
Just to confirm, there are 2 grounds. One engine ground and another bolted to the ECU itself?

Can someone check with their bike not running what voltage the ECU reads vs the actual voltage measured at the battery?
 

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Discussion Starter · #8 · (Edited)
I did install an 848 flywheel which is lighter than the OEM 1098 flywheel. I didn't go near the CPS, but is it possible it is out of adjustment by removing the left side cover?

So far causes of a non firing cylinder(with spark out of the cylinder) are bad plug, weak coil, loose wire in coil connector, weak ground, cam timing, and CPS air gap out of spec.

The first thing I want to check is the bad ground because I don't recall my ECU/Dash reading 1V lower than what I measure at the battery terminal. maybe .1-.2V less. I'm seeing 13.5V at the battery but ECU is showing 12.5-12.6V.
Can someone confirm that this isn't right by measuring their actual battery voltage vs ecu voltage with key on and bike not running?
 

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I did install an 848 flywheel which is lighter than the OEM 1098 flywheel. I didn't go near the CPS, but is it possible it is out of adjustment by removing the left side cover?

So far causes of a non firing cylinder(with spark out of the cylinder) are bad plug, weak coil, loose wire in coil connector, weak ground, cam timing, and CPS air gap out of spec.

The first thing I want to check is the bad ground because I don't recall my ECU/Dash reading 1V lower than what I measure at the battery terminal. maybe .1-.2V less. I'm seeing 13.5V at the battery but ECU is showing 12.5-12.6V.
Can someone confirm that this isn't right by measuring their actual battery voltage vs ecu voltage with key on and bike not running?
My dash reading is normally 0.2V higher than the voltage measured directly across the battery terminals.
 

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Discussion Starter · #10 ·
My dash reading is normally 0.2V higher than the voltage measured directly across the battery terminals.
holy crap, a magical dash! It's creating more power than the battery is outputting! j/k. I think you mean the dash reads lower than the battery.

I just double checked and cleaned my grounds. Didn't try cranking her over yet because I want to check the injector again to make sure it's actually opening properly. The airbox and injectors were off the bike without fuel for cleaning over the winter I hear this can cause them to freeze or gum up. After that i'll go on to switching the coils.

My last option is to pop off the valve cover to recheck my cam timing. I'm pretty sure it isn't on the wrong stroke. I think its still getting compression.
 

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holy crap, a magical dash! It's creating more power than the battery is outputting! j/k. I think you mean the dash reads lower than the battery.

I just double checked and cleaned my grounds. Didn't try cranking her over yet because I want to check the injector again to make sure it's actually opening properly. The airbox and injectors were off the bike without fuel for cleaning over the winter I hear this can cause them to freeze or gum up. After that i'll go on to switching the coils.

My last option is to pop off the valve cover to recheck my cam timing. I'm pretty sure it isn't on the wrong stroke. I think its still getting compression.
Nope dash reads higher. I think its more likely that the 2 different multimeters I used to check it are more accurate than the dash display - rather than the dash generating it own power.
 

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Discussion Starter · #12 · (Edited)
OK not the plugs and not the coils. Injector seems to be working. Rear cylinder still won't fire. Only things I can think of are corrupted ecu or can timing which i had set to 105/108 same as the horizontal. Any other suggestions?

I doubt I timed the cams on the wrong stroke but I'm going to double check it on Saturday. If i timed the cams on the wrong stroke, I would think it would be really hard for the starter to turn the motor over. Any other ideas? I'm really hoping its not the ECU. Its definitely getting fuel and spark and compression.

Would a bad or misadjusted CPS cause just one cylinder not to fire? I noticed that if i unplug the horizontal cylinder which works, the engine will keep cranking until I key off and not stop like it normally does after a certain number of cranks. Does that give a clue?
 

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I'm betting on the cams being out of phase. I inadvertently did this on a bike a couple of years ago and it only fired up on the horizontal cylinder. I spun the cams 180 degrees and all good. The rear cylinder fires 270 degrees AFTER the front one. I made the mistake of assuming that also means it fires 90 degrees BEFORE the horizontal but in practice it doesn't work out that way. The engine still cycles just fine and shows compression but it's sparking on the exhaust/intake overlap rather than the actual compression stroke.
 

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Discussion Starter · #14 ·
Thanks EL Twin. I'm starting to think the same thing but I'm driving myself crazy trying to figure out how I did that. I could have swore I marked the cams and belts when i pulled them out to do the valve adjustment. Oh well. I'll check it again tonight if I have time. At this point that has to be the only thing left that makes sense.
 

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Discussion Starter · #15 ·
I think its the cam timing. The timing dimple indicates horizontal tdc. 270 degrees later, vertical is at tdc with the valves opening/closing. I need to flip 180
 

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I may be stating the bleeding obvious to many of you, but the two cylinders fire on alternate revolutions. This is vital for engine balance and even power output.

On one engine revolution the front cylinder fires, and on the next revolution the other cylinder fires.

So in a total of 720 degrees of rotation (2 x 360) the two cylinders fire at 270 and 450 degrees. This was discussed recently in a thread where the owner of an 848 Evo had problems with the cam timing marks.

So to check your timing you should have the cams at the inactive/TDC compression setting on the front cylinder when the crossover shaft pulley marks are aligned, then after turning the engine forwards 3/4 of a revolution (to rear cylinder's TDC) the rear cylinder marks should align.

Of course care must be taken when rotating the engine if the cam timing is incorrect..
 

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Discussion Starter · #17 ·
Yup looks like my cams were 180 out. I feel so stupid. I don't know how I did that. I remember marking the belt and can pulleys. Maybe the bottom pulley shifted. Im pretty sure that's the main problem but I do have a cps code too so I'm waiting for my replacement before firing her up.
 

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Discussion Starter · #19 ·
Keith I hope you figured it out reading/looking at this thread is bumming me out.
I think i have it figured out. I'm getting pretty quick with tearing the bike down to the point where i can degree the cams. I made a jig with threaded rods and a piece of flat stock to set up my dial indicators.
Vertical cylinder cams were 180 degrees out. I do have a CPS code and a replacement unit will be here wednesday, so hopefully I will be attempting to start the bike then.

I still don't understand how i got the cams 180 degrees out but I'll just be happy once its running again.
 

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Discussion Starter · #20 ·
yup feel like such an idiot. Got it idling today and up to temperature to bleed the cooling system. I'm getting an intermittent CPS code so I will be replacing it and gapping it properly when it arrives Friday. Thanks everyone!
 
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