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Discussion Starter #1
I have tried swapping, coil, cable and plugs. Vertical cylinder runs fine, horizontal does not. I have tried changing ECUs (immo disabled), so it isn't the old bad 2002 ecu issue, same cylinder has issue.

Pulled plug and touched face to ground, turned over engine no spark in the horizontal but spark on the vertical.

Now I am not sure what else to check. I verified continuity between the ecu and the coil wiring before, and it seemed fine.

what else can I do?
 

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A few other people have had similar issues that turned out to be a faulty, or improperly shimmed, crankshaft position sensor.

Good luck!
 

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That would be my guess as well. Replacing the sensor on my long departed 98 st2 cured the one cylinder only syndrome. My problem was intermittent however. Thing would drop the cylinder at the most inopportune time. Usually while passing!...Will
 

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Discussion Starter #7
thanks, I found it and pulled it out to see if there was anything obviously wrong, but no luck there. Had to drain some of the water as there was no way to get it out with the hose in the way.

I'm going to find the connector in the morning to see if I get 600 ohm, I couldn't see it for all of my looking.

Im still not sure how to set the gap properly though. Nothing really describes that and once you shove it in, its in.

There is a spot with a screw next to the sensor that looks like it could be covering an access hole to set the gap, but I am not about to just haphazardly unscrew stuff on a ducati. :)
 

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Believe it or not, I went through all these issues with my 02 st4s and guess what? It turned out to be a crappy spark plug! I couldn't believe it cause it only had about 3k on it. I changed the crank sensor, etc, set tps, etc, you name it, now runs fine with a new spark plug.

I think I may have a weak coil or semi weak plug wire, but sometimes it is the simplest things!

Try new plugs, it is a cheap try,

Mark
 

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Just saw, you did try plugs,

Sorry,

Mark
 

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Discussion Starter #10
Yep, the plug from the H is in the V and visa versa now.

As for the CPS, I figured out where the connector was. Somehow I kept getting lost in the wiring and going the wrong direction. Resistance is ~880 to 1100 ohm as it spins around. My multimeter isnt fast enough to really tell me much more detail than that.

So whatcha think, is that "enough" to mean the cps is dead and I need a new one? I really don't understand how it would be screw up with horizontal vs vertical cylinders unless it is supposed to give a different reading for each?
 

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Gotham has a used one for sale for $25. I remember that they are around $100 new.

http://www.gothamcycles.com/servlet/the-682/Ducati-Timing-Pickup-Sensor/Detail

Even though it may not be the cause, if it was me, I'd give it a shot for a few bucks. Maybe email him and see if he can check the resistance.

Also, read the end of the first linked thread that I posted. It talked about cleaning and checking the connections at the other end of the wire loom.

That thread also mentions that the ideal impedance is 600 ohms for the CPS.
 

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Discussion Starter #12
thanks, I sent them an email. I have already cleaned the connections. Everything looks good.

I have read through every post here and in other locations talking about bad crank or timing position sensors. None talk about consistent running on one cylinder. So I am not sure but honestly I don't have any other options at this point.

Its either this or my second ecu has failed in the exact same was as the first one.

BTW: I tried all the wire wiggling I could think of to see if there was some kind of bad connection somewhere, but I cant find anything.

Question though, I have found where the grey/blue and grey/green wires terminate back in the ECU but I was unable to find out where the brown/white wires terminate. both coils get the same color cable. Anyone have any ideas on that?
 

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Discussion Starter #13
VDSTS plugged in and it states p0351 "Open Circuit" so it doesn't appear to be the cps. Since I switched the coils, its not that. The only other things are wiring (seems to check out) and lastly the ecu.

Anyone know how to pull a pin from the ecu connector safely? I want to try to bypass the grey/blue with another wire.
 

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VDSTS plugged in and it states p0351 "Open Circuit" so it doesn't appear to be the cps. Since I switched the coils, its not that. The only other things are wiring (seems to check out) and lastly the ecu.

Anyone know how to pull a pin from the ecu connector safely? I want to try to bypass the grey/blue with another wire.
I googled P0351, and found numerous articles that said that the ECU (not just Ducati) will throw this code when "the ECM detects a problem in the spark timing 1 circuit, it will set DTC P0351." This happens when the ECU detects a problem with the primary coil, not simply a broken circuit, even though that may be the cause. The code is thrown when 80 cycles have occurred without a signal from the primary coil circuit.

Granted, I haven't delved into this too much, but in electronic ignition systems, there are two coils per bank, primary and secondary (for the Duc, each cylinder is a bank). The job of the primary is to be very sensitive, and when triggered, the field will collapse and trigger the secondary coil to discharge and send the current to the plug to fire.

With a newer Duc, I'm not sure where the primary coil exists, but it is entirely possible that it is inside the CPS. If not, it would need to be in the ECU itself.

When you look at the secondary coils on the ST, there is a high-tension lead (going to the spark plug), and the main lead, but also a control lead. Where does that go?

And, finally, since it is only one cylinder that is not running, and swapping secondary coils doesn't change the outcome, it would seem logical to me that the primary coil for the failed cylinder is what has failed. Find that, and you should have found the problem.

Good luck!
 

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Discussion Starter #15
no, it isn't in the cps. The cps is completely separate for the 59m and has its own error code.

In this case the error means that the circuit that goes from the 12v relay power through the brown/white wire to the coil and then back on the grey/blue wire is not making it for some reason, or that the ecu is unable to lift said circuit. You are correct though the lifting breaks the ground and the HV stored in the coil then is transferred to the sparkplug because it is grounded.

so if the brown/white cable is broken somehow, the white/blue cable, the coil, the cable isn't connected properly or the ecu is busted this error should show up. The CPS should not be involved.
 

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Have you tried turning it over in the dark and looking for arcs?
 

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Have you tried turning it over in the dark and looking for arcs?
I found a really odd problem with my 02 ST4s.

At high speed, 80mph+, when I'd come up behind a cage on the motorway, if I flashed him with the high beams a few times, it would often drop onto one cylinder. The horizontal cylinder would go. My independent Ducati guy said coils. So I fot a secondhand coil off that eGhay (from a 916) and the problem has never resurfaced.

Strangest bit was, it took me a few goes to work out that it would continue to run on one cylinder until I switched the lights off altogether, then switched 'em back on again, hey presto, from 498cc, back to 996cc!

Odd!

A
 

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I found a really odd problem with my 02 ST4s.

At high speed, 80mph+, when I'd come up behind a cage on the motorway, if I flashed him with the high beams a few times, it would often drop onto one cylinder. The horizontal cylinder would go. My independent Ducati guy said coils. So I fot a secondhand coil off that eGhay (from a 916) and the problem has never resurfaced.

Strangest bit was, it took me a few goes to work out that it would continue to run on one cylinder until I switched the lights off altogether, then switched 'em back on again, hey presto, from 498cc, back to 996cc!

Odd!

A
Secondary coil failure and the issue with the lights sounds like a bad ground somewhere.
 

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no, it isn't in the cps. The cps is completely separate for the 59m and has its own error code.

In this case the error means that the circuit that goes from the 12v relay power through the brown/white wire to the coil and then back on the grey/blue wire is not making it for some reason, or that the ecu is unable to lift said circuit. You are correct though the lifting breaks the ground and the HV stored in the coil then is transferred to the sparkplug because it is grounded.

so if the brown/white cable is broken somehow, the white/blue cable, the coil, the cable isn't connected properly or the ecu is busted this error should show up. The CPS should not be involved.
I may sound like a broken record, and you are free to ignore me, but hear me out.

Evidence to date:

* One cylinder firing
* Secondary coil swap (as well as plugs and wires) doesn't solve problem
* ECU swap did not solve problem
* CPS tested higher than normal resistance
* Error code P0351 thrown indicating problem with primary coil circuit

Now, it is entirely possible that a bad wire / connector / ground is the problem, but I wanted to mention that this could still be the CPS' fault.

The reason that the ECU doesn't flag the CPS as bad, is because the part is marginal, and not failed. It is still allowing one cylinder to be picked up and fire, and it has continuity, albeit at a higher resistance. However, the extra resistance in the CPS may be enough to not trip the circuit for p-coil 1 in the ECU.

The ECU will have a threshold with which to discharge the s-coil, so as not to interpret stray EM noise as signal. The added resistance may make the CPS signal fall below this threshold, preventing p-coil 1 circuit from closing.

Someone on one of the other forums suggested dissecting the CPS connector, and swapping the signaling leads for p-coil 1 and 2, and seeing if the other cylinder starts firing. This is of course with the plugs out of the cylinders, as you don't want the cylinder firing in the wrong order. But, it would prove that it's the pickup and not the circuit or wires.

Good luck!
 

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Secondary coil failure and the issue with the lights sounds like a bad ground somewhere.
Bad ground you say? And were a chap to start to look for a ground that might cause such an offence, where would a chap start?

[listens intently]

A
 
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