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What's up everyone... looking for some opinions. I recently took my '02 748R to my "local" Ducati dealer for some work (rocker replacement, new belts, new tires, etc. etc.) and after getting everything buttoned up and restarted they find that it was running on a single cylinder only. I have the Factory Pro EPROM in there, so to eliminate that as a source of the problem I brought them the OEM EPROM and the problem still persists. This sounds like an ECU issue to me, but before I start to search for a replacement I was wondering what you guys thought.

It was a pretty awesome run... I've not put a ton of miles on it, and it did get a full rebuild in 2011 once I got it, but that bike worked flawlessly for the original owner and myself for 15 years.
 

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I have a good spare you can try. PM if interested.
 

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Morning Proph. Did you ride it there or trailer it. If it went in running on two cylinders and dropped a cylinder on start up after the work i see it more that the mechanic fucked something up. Somehow can't see it as the ecu gone south. I could be wrong.
 

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I have seen ecu's go bad I would swap with a known good unit first as there could be other causes and if you can swap ecu it will save time (which = $$). It would not be common to fail instantly so yes you/they need to check for something unplugged. There is no need to pull the coils but check them for being disconnected, a more likely cause would be a disconnected injector as you have shower injectors on that bike they do remove them for service. Simple to check for spark as well as fuel on the dead cylinder to narrow things down.
 

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Discussion Starter #8
hows the fuel flow? any spark? bad plug?connectors all ok to the coils? could the timing be off???
I last rode it in late September, a couple of weeks before I brought it in for service and it was running like a top, as it always has. I spent some time with them there last week when I brought them the OEM EPROM and we went through the checklist. Both shower injectors are working fine when cables are swapped, plugs are good, coils and cables work when swapped...
@SS904 is going to get his spare 1.6m and EPROM here next week so at that point if it is still not running then we can start to look into what may have been fucked up when they were doing rockers/valves/belts.

There is one thing, I am just now thinking of it... the day I went to take it up there it would not start. So my buddy and I wheeled it out of my office and pushed it around to the driveway. As I said, I had just ridden it a couple of weeks previously without issue, but that day it refused to start. On a hunch, I opened the gas cap and listened during the startup sequence and sure enough, when the fuel pumps started priming I could hear fuel pissing out in the tank... one of the fuel lines was split. When I got it up there to them I asked them take care of the fuel pump lines as well. I suppose that is one more thing we can look at? What do you guys think... is that something that could cause this type of problem? The fact that everything from an ignition spark and fuel supply standpoint seem to be working fine is what makes me think it is ECU/EPROM related, but you guys have WAY more collective experience with this than I do so I am of course open to any suggestions you have.

And again, thanks as always for the help... it is much appreciated.
 

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Don't reject this suggestion out of hand, I've seen it where the cps has for one reason or another needed shimming right down to just a few thou clearance on the gear before it would fire two cylinders.
Changing the cps made no difference and just why this is so defeats me but it worked so far on both a 748 and a 1000DS.
My mate with the DS spent a fortune changing ecu, wiring harness, throttle bodies and injectors etc before he tries re-shimming the cps.
Obviously something else is behind the problem but swapping ecu's and other things made no difference but closing that gap right down fixed the issue.
Worth a try.
You can make thin shims from blister packs really easily and quickly.
Ecu chip not properly seated is another potential culprit.
Recently my 853 started mis firing and dropping a cylinder.. I stripped the ecu and checked for dry soldered joints, dis-assembled the big harness socket,
cleaned every pin to no avail until I noticed when slightly lifting the big plug with the motor running the problem went away.
Checked the socket and wires yet again... no go. i then assumed that the clip and plastic tag holding the plug in had somehow lost tension over time so I went straight fron A to C and strapped the sucker in with two big cable ties right around the ecu and plug and quess what.. the problem is gone and the bike has never run better.. sometimes it's just the simple things..
Sometimes it's just the simplest things that stick you up.
 
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I last rode it in late September, a couple of weeks before I brought it in for service and it was running like a top, as it always has. I spent some time with them there last week when I brought them the OEM EPROM and we went through the checklist. Both shower injectors are working fine when cables are swapped, plugs are good, coils and cables work when .
What am I missing Proph? It has spark? It has fuel? Then technically it should start:)
 

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For the not starting: One time before I went on a 400 mile day trip I could not get my old 748 (Haruko-chan) to start. I ran the battery down cranking. Then I attempted to push start it for about 15 minutes with negative results. I took a break, then gave it a final push start. It started right up and I rode 120 miles before I turned it off. Everything was normal after I fill up the tank and started her up. I don't know what was wrong in the first place, but it never happened again.

But in your case I think that it is catastrophic. I will go out of my way for you, b/c I am nice, and pay your service bill on top of the $3k for a broken 02' 748R in pristine condition. I can pick it up as soon as you like. This is me looking out for you.

Has fuel and spark on both cylinders been verified?
 

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Good start on diagnosing things.

so to recap.

One cylinder will not run.
when you swap coils/wires that cylinder has spark but not when as originally paired?
When you swap injectors that cylinder suddenly has fuel but not when as originally paired?

Each time you swap something whatever you have connected to the dead cylinders fuel or spark does NOT work?

If it were the TPS nothing should work as the tps signal is the same for both and the ecu decides where either is located.
You tested the oem chip with no change so that"s out.
A split fuel line will cause problems so have them simply test fuel pressure. Doubtful but possible as it would effect both cylinders not one.
The ECU will be worth swapping to test as it fits the bill of effecting one cylinder only and you already tested that the chip,coils,injectors and wiring are working.

If the ECU does not help They need to pull out the schematic and test for power/ground loss to the one cylinder.
Do you have NO fuel AND no spark on that cylinder?

Stranger things have happened I had a Husky 610 ride into the shop for me to change a water pump gasket. After the job the bike would not start, I spent hours diagnosing it sure we had screwed something up we touched. In the end we discovered the flywheel had unbonded from the shaft so it no longer had ignition timing. Luck of the draw, we had nothing to do with the problem as the flywheel is under the right side cover and we were only on the left side top end. Sh#T does happen.
 

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hows the fuel flow? any spark? bad plug?connectors all ok to the coils? could the timing be off???
Don't seem to have answered this post.


As far as I can tell from your narrative, we have no information of whether you have spark or fuel on the non running cylinder. You denote the components working and then go to an assumption the ECU is the problem. Do you actually know whether it is fuel or ignition or both?

How much fuel was in the tank when you heard the sound?

In the course of the repair, did they do anything electrical other than disconnect the battery? Was the battery removed? Are the battery connection per stock on your bike with a normal sized battery installed that would not be conducive to improper hookup?

You also didn't answer the PC installed question. Are all ECU and ignition/FI connections stock?
 

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Discussion Starter #14
What am I missing Proph? It has spark? It has fuel? Then technically it should start:)
Technically yes, it should. ;) Each of the coils, when tested individually is working fine, same for each of the shower injectors... and the bike does start, however it is running on a single (horizontal I believe) cylinder.

Like I said, am going to toss @SS904 's spare ECU in there and see if that corrects the problem. If it does not, then somebody fucked something up... and it wasn't me. ;)
 

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Discussion Starter #16
hows the fuel flow? any spark? bad plug?connectors all ok to the coils? could the timing be off???
It was running fine a couple of weeks before I trailered it to the dealer... I suppose all of these points of failure are possible, and if the ECU swap does not solve the problem then we'll be running down the list to eliminate or confirm each as the source.
 

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Technically yes, it should. ;) Each of the coils, when tested individually is working fine, same for each of the shower injectors... and the bike does start, however it is running on a single (horizontal I believe) cylinder.

Like I said, am going to toss @SS904 's spare ECU in there and see if that corrects the problem. If it does not, then somebody fucked something up... and it wasn't me. ;)
Same thing happened to my 916 this summer. The vertical cylinder stopped working. I finally determined that the vertical injector was not firing. The problem did not follow the injector when I swapped them around. The harness tested good, which left me with a bad 1.6 ECU. I went aftermarket and bought a myECU from Cliff Jeffries - my thought was a used 20-some year old ECU could bad in the same way my original did, and at least the myECU is repairable.

John
 

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Discussion Starter #19
But in your case I think that it is catastrophic. I will go out of my way for you, b/c I am nice, and pay your service bill on top of the $3k for a broken 02' 748R in pristine condition. I can pick it up as soon as you like. This is me looking out for you.
Not sure where I would be without the collective help of everyone on this forum... gestures like this show me how much you really care. I'll keep your offer in mind... ;)

Has fuel and spark on both cylinders been verified?
Well... each of the coils was tested and generates a spark from each of the plugs, and each of the shower injectors was tested and works. What I do not know, as I totally spaced on asking, is whether or not the problem, when the bike is started, is fuel or ignition. Plan to spend some time with them this week and see if I can help troubleshoot when I get the replacement ECU.

Pretty cool bunch of guys at Razee's in RI by the way... unfortunate that this occurred and am hopeful the ECU swap solves the problem.
 

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Don't seem to have answered this post.
Sorry sir... my bad. I posted this and then bailed for the weekend in Newport. Pretty cool snowfall all day long on Saturday...

As far as I can tell from your narrative, we have no information of whether you have spark or fuel on the non running cylinder. You denote the components working and then go to an assumption the ECU is the problem. Do you actually know whether it is fuel or ignition or both?
That is correct... all of the components, when tested individually, are functioning as they should. Because of this, the guys at Razee's felt the easiest things to test for in the functional chain was the EPROM and the ECU. I swapped the original EPROM and it still exhibited this problem so next candidate is the ECU. Fortunately, @SS904 has a spare which he is going to let me try.

How much fuel was in the tank when you heard the sound?
About half a tank left after the last ride. One of the lines was definitely split as I could see and hear fuel spraying out from it, onto the surface of the fuel in the tank. This issue will be one of the first things I look at if the ECU swap does not work... am thinking that if the lines in the tank were degrading to the point where they split, could they also have been discharging particles of line material into the fuel that have obstructed flow in the shower injectors?

In the course of the repair, did they do anything electrical other than disconnect the battery? Was the battery removed? Are the battery connection per stock on your bike with a normal sized battery installed that would not be conducive to improper hookup?
Yep... battery was removed. It is a Shorai LFX18A1-BS12... this is the one with the terminals swapped so that they match the OEM positive/negative terminal orientation.

You also didn't answer the PC installed question. Are all ECU and ignition/FI connections stock?
No PC, stock ECU, stock coils, stock pretty much everything other than the Factory Pro swap.
 
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