Kiwi_Roy Posted December 21, 2015 Share Posted December 21, 2015 Meinolf, You say to use a CO tester or Wide Band O2 sensor to set the CO trim. Could you elaborate a little more on setting the CO using the WB O2 sensor, what mixture ratio should we aim for at idle. Is there a mixture that idles better even though it might not be best for power. I assume the CO tester reading is a different No from the Mixture ratio, what is the target? Is a CO tester something you might have in the usual home garage? Is there a way of fudging the trim without either instrument? Link to comment Share on other sites More sharing options...
Meinolf Posted December 21, 2015 Share Posted December 21, 2015 Hi Roy, 1. Could you elaborate a little more on setting the CO using the WB O2 sensor 2. what mixture ratio should we aim for at idle. Is there a mixture that idles better even though it might not be best for power. 3. I assume the CO tester reading is a different No from the Mixture ratio, what is the target? 4. Is a CO tester something you might have in the usual home garage? 5. Is there a way of fudging the trim without either instrument? let me answer in the same sequence. 1. CO and Lambda are equivalent. See the chart here for the values: http://www.mad-d.ch/attachments/063_Umrechung%20Lambda.pdf . So you might go after a CO value of 5.00 using the CO tester or a Lambda value of 0.86 or an AFR of 12.63 using the WBO2, it's all the same. 2. Here it get's a bit more sophisticated. Mixture is one part of the equation, ignition the other. The speed at which the mixture starts burning depends on the AFR. A lean mixture ignites slower than a rich mixture, so the ignition should be changed following the mixture. Normally one wouldn't have the means to determine the best ignition timing in his home workshop or garage, so this part of the equation should be disregarded. Focusing only on the mixture it's really depending on what your targets are. The V11 and Jackal idle well at Lambda up to 0.96-0.97. Anything leaner requires engines which are specifically designed for a >1.0 Lambda ratio and employ very sophisticated technologies. Guzzis aren't. For all intents and purposes any mixture up to 0.97 Lambda is ok, personally I've set 0.92. Some more details here: http://www.cartechbooks.com/media/wysiwyg/9_12.jpg 3. See 1. 4. Well, here in Germany a CO tester is cheaper than a WBO2 sensor and logger. But, the latter one is more versatile. For example in measuring both cylinders and synchronizing the mixture, the ECU has 2 fuel maps, one for each cylinder. And getting these synched gives a real boost plus lower vibrations. 5. Yes. Like we did with the old-style carburetted engines and the idle mixture screws. Adjust CO values upwards until the rpm drops, adjust CO downwards until the rpm drops, select the CO value in the midst. That would be 0.86 or close to it. Cheers Meinolf Link to comment Share on other sites More sharing options...
Kiwi_Roy Posted December 21, 2015 Share Posted December 21, 2015 That's very interesting, especially the chart, so obviously when you are accelerating the mixture needs to be richer hence the reason for having an accelerator pump on a carb. Does the 15M ECU have an equivalent to the pump, I guess it adds to the injector open time for a brief period. I think the ratio is mass of air to mass of fuel If you look at how the mass of air changes with temperature and altitude it's easy to see why the sensors are so important, maybe more so than with a carb. BTW If you google the Efiman document it gives a good explanation of fuel injection Although its for an earlier P8 ECU much of it still applies. Link to comment Share on other sites More sharing options...
Gottagetone Posted December 21, 2015 Share Posted December 21, 2015 Ive been messing with the bike and have the idle back down to about 1000 rpms and now its backfiring into the intake at that rpm where before it was only doing it at around 2800-3000. Its time for a pro to look at it and get it back in order. Its become an act of frustration and thats just not fun. I love fixing stuff and am pretty decent with a wrench but this is something that I think will require more skill and tools than I have. Ill report back once the verdict comes in. Thanks for all the input, it really has been helpful and I have learned quite a bit. Cheers and Merry Christmas! Link to comment Share on other sites More sharing options...
Kiwi_Roy Posted December 21, 2015 Share Posted December 21, 2015 You gave it your best shot, sometimes it pays to back away. Merry Christmas back at you. Link to comment Share on other sites More sharing options...
Gottagetone Posted December 22, 2015 Share Posted December 22, 2015 Well I have not quite given up just yet. I worked on it a bit more today and its a bit better but not right just yet. I spoke to the local Guzzi tech and he confirmed that I had the TPS set correctly but that the balance was critical. He did say that rarely does he see one that needs an air bleed screw open more than 1/4 turn. I reset the left side intake boot and balanced the TBs at idle. Under acceleration they are apart more than they should be but if I adjust it then they are apart at idle. The tech said that since I adjusted the TPS that they need to go in and tell the ECU that the adjustment had been made...or something like that. Never the less, the problem of the backfire is still there but it seems a bit better. Ill prolly change the plugs even though they only have abeout 1200 miles on them but they are cheap and it will rule that out. If I figure anything else out ill let ya know. Cheers! Link to comment Share on other sites More sharing options...
Scud Posted December 23, 2015 Share Posted December 23, 2015 Glad to hear you are getting closer. I was really frustrated for a while too - and frankly, I'm still a little nervous about doing it again (I don't want to mess it up). Based on your description, I'm wondering if you might have a little play in your throttle linkage. At higher speeds - say 3,000 RPM - there is one type of pressure on the linkage - the throttle cable pulling against the pressure of the throttle-body springs. The throttle bodies should stay in about the same balance while riding. Then when the throttle is released for idle, a different pressure is applied to the linkage - this time from the mechanical stops against the idle screws. So that's theory... and here is an idea about application: After getting balance at 3,000 RPMs, test to see if the throttle stops are resting equally on both idle screws. If not, maybe you could adjust one of those screws to even out your idle - it will not affect the application of the throttle. I don't have an idea regarding backfiring. If you do end up taking it to the shop, you'll be in a great position to understand what they did. And share the "magic" with us. Link to comment Share on other sites More sharing options...
Kiwi_Roy Posted December 23, 2015 Share Posted December 23, 2015 If the balance is only out a few inches of oil don't worry about it, that's nothing. Fine tune the idle balance with one air bleed screw. Scud is probably right about your linkage. Still backfiring so it must be something else eh! Sent from my shoe phone! Link to comment Share on other sites More sharing options...
docc Posted December 23, 2015 Share Posted December 23, 2015 Well I have not quite given up just yet. I worked on it a bit more today and its a bit better but not right just yet. I spoke to the local Guzzi tech and he confirmed that I had the TPS set correctly but that the balance was critical. He did say that rarely does he see one that needs an air bleed screw open more than 1/4 turn. I reset the left side intake boot and balanced the TBs at idle. Under acceleration they are apart more than they should be but if I adjust it then they are apart at idle. The tech said that since I adjusted the TPS that they need to go in and tell the ECU that the adjustment had been made...or something like that. Never the less, the problem of the backfire is still there but it seems a bit better. Ill prolly change the plugs even though they only have abeout 1200 miles on them but they are cheap and it will rule that out. If I figure anything else out ill let ya know. Cheers! Backfiring is so often a function of some kind of unmetered air/exhaust leak, or throttle bodies out of synch. Bad or loose rubber intake connections, open intake vacuum tap, loose/leaky exhaust connection. FWIW, I can't agree with the tech you spoke to. Very small air bleed openings have been terribly unforgiving at idle (where they do their work) in my experience, and *no* the ECU doesn't have to be 'told', it "sees." Before going further, it would be advisable to make sure your CO fuel trim is not set at some stupidly low (federal) level. Guzzidiag and the proper cabling is worth the investment! Link to comment Share on other sites More sharing options...
Gottagetone Posted December 23, 2015 Share Posted December 23, 2015 The tech i spoke to is top notch, he works at Pikes Peak with Ducati, since they trust his judgement, I trust his judgement. Ive checked for intake leaks but I think I find something new overtime I look at it. Ill continue to fiddle with it but most likely it will go to the shop after the 4th. Link to comment Share on other sites More sharing options...
docc Posted December 23, 2015 Share Posted December 23, 2015 Not everything that applies to Ducati applies to the V11, not disputing that he is a top-notch Ducati tech. I just can't imagine you'll get your V11 to run right with the air bleeds at 1/4 out. His assertion that the ECU needs to be told about the TPS change might apply to what he's used to working on , but not the ECU in the V11. I commend you for hanging tough working through all the frustration of getting your V11 running right! You can do this! Link to comment Share on other sites More sharing options...
docc Posted December 23, 2015 Share Posted December 23, 2015 BTW, how do your battery voltages look (OCV, cranking, idle, and at some rpm)? Link to comment Share on other sites More sharing options...
Gottagetone Posted December 23, 2015 Share Posted December 23, 2015 Voltage is good, 12.5v sitting off, a bit higher when started. Link to comment Share on other sites More sharing options...
Meinolf Posted December 23, 2015 Share Posted December 23, 2015 Hi, I reset the left side intake boot What does this mean? Under acceleration they are apart more than they should be but if I adjust it then they are apart at idle. re-read my earlier post. The mechanical synchronization with closed throttle is done with both idle stop screws, with open throttle it's done with the white screw on the connecting rod. The tech said that since I adjusted the TPS that they need to go in and tell the ECU that the adjustment had been made...or something like that. The 15M/15RC doesn't have this functionality. Later ECUs do. The ECU can neither sense if an adjustment of TPS has been made nor can it be told. It reads the voltage coming from the TPS and uses the according breakpoints in the maps. Assume that, if you have backfiring at constant throttle opening, the engine is running much to lean due to lean map values or a leak on the intake side. If it backfires while closing the throttle, you might have a leak in the exhaust as well. Cheers Meinolf Link to comment Share on other sites More sharing options...
Paradiso Posted December 23, 2015 Share Posted December 23, 2015 You haven't by any chance disturbed the timing sensor recently have you? If this is slightly out of position it can cause back-firing and uneven running at low revs. Sent from my GT-I8190N using Tapatalk Link to comment Share on other sites More sharing options...
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