Guest ratchethack Posted February 6, 2009 Posted February 6, 2009 could you just put a variable resistor in line and w/an Ohm meter follow readings to find out what the optimum reading "should" be.? Then correct the the sensor with a small resistance? I'm not afraid to ask dumb questions! Yep. John A posted his experience doing exactly this so he could adjust "on the fly" nearly 2 years ago, back in post #51. I'm getting closer to doing this meself, but always prefer to go less complex and less fiddly whenever possible.
raz Posted February 6, 2009 Posted February 6, 2009 Are you sure this is not just a variant of "tuning by misadjusting the TPS sensor"? Just a thought. I have a pretty firm opinion that the sensor should have as good thermal coupling as practically possible, and (here comes the punch line) if this detunes the engine the map should be adjusted. Probably including - but not limited to - the correction table for "oil" temp. But, hey, it's winter. I'll be happy to discuss it further. Besides, I don't have strong feelings against tuning by misadjusting the TPS sensor, if you can't afford a remap. In fact it makes much more sense than having a temperature sensor isolated from the heat it was supposed to sense. And even varying that isolation until it seems to perform well at the time Just my and don't let me stop you from wonderful trial'n'error
Guest ratchethack Posted February 6, 2009 Posted February 6, 2009 Are you sure this is not just a variant of "tuning by misadjusting the TPS sensor"? Raz, I'm about as certain as I can be at this point that this is exactly wot this is -- nothing more nor less. I have a pretty firm opinion that the sensor should have as good thermal coupling as practically possible, and, this is the punch line, if this detunes the engine the map should be adjusted. Probably including - but not limited to - the correction table for "oil" temp. Aye. I submit that most existing custom maps (including the one I'm using) have been created without good thermal coupling. . . . I don't have strong feelings against tuning by misadjusting the TPS sensor, if you can't afford a remap. In fact it makes much more sense than having a temperature sensor isolated from the heat it was supposed to sense. I'm merely experimenting here to determine if I can optimize running by tweaking the heat flow between the cylinder head and the sensor with the map I've got -- Why, it's nothing less than a shameful miscarriage of tuning propriety! Ideally, I'd be dynotuning a new map with as direct thermal connection between head and sensor as possible. If the bike actually ran anything approaching poorly as is (with the exception of a few niggling nits, by all objective measures it runs perfectly with the OE sensor holder without thermal conductive paste), I'd have re-mapped it long ago. Just my and don't let me stop you from wonderful trial'n'error Stop? Me? Perish the thought! Ain't this exactly the kinda thing wot Winter is for?
fotoguzzi Posted February 7, 2009 Posted February 7, 2009 In fact it makes much more sense than having a temperature sensor isolated from the heat it was supposed to sense. I had that thought too.
Dan M Posted February 7, 2009 Posted February 7, 2009 Are you sure this is not just a variant of "tuning by misadjusting the TPS sensor"? Just a thought. I have a pretty firm opinion that the sensor should have as good thermal coupling as practically possible, and (here comes the punch line) if this detunes the engine the map should be adjusted. Probably including - but not limited to - the correction table for "oil" temp.But, hey, it's winter. I'll be happy to discuss it further. Besides, I don't have strong feelings against tuning by misadjusting the TPS sensor, if you can't afford a remap. In fact it makes much more sense than having a temperature sensor isolated from the heat it was supposed to sense. And even varying that isolation until it seems to perform well at the time Just my and don't let me stop you from wonderful trial'n'error I with ya on this Raz. I've been witness to so many tweakers screwing things up in the name of performance I can't count them. I'll admit to doing it myself. More often than not people will make a change, cause a problem, change something else to compensate and cause yet another problem. The old adage "can't leave well enough alone" is the bane of tinkerers. If we own & ride Italian motorcycles we must be tinkerers at heart so it is quite difficult for most to leave things alone. Two years ago after all of the mods I did to my bike I was running an off the shelf map and my bike was running about as close to perfect as I could want. Last winter for no good reason other than I was bored and had been dipping into the forum too often, while doing various things in the garage I decided to give this supposed troublesome temp sensor and it's designed by the devil plastic holder a look. I found the sensor to be finger tight. Well, this had to be reconciled. So I removed it, packed it with paste and reinstalled it quite satisfied that now things had been perfected in my Guzzi world. This past riding season I experienced poor, lean running, especially in hot weather. Did I go back to the scene of the crime? No. I started futzing elsewhere, looking for vacuum leaks, checking the never touched TPS and adjusting my map that had been perfectly suited to my bike the year before. I made improvements but never really had it to the spec of 2007. I have done nothing to the goose this winter but before spring I will restore the sensor to it's original unpasted state and go back to my old map. Sorry for the ramble, it's winter here too... 1
emry Posted February 9, 2009 Posted February 9, 2009 I just thought I would add these pics. Who ever is better able to determine a proper outcome, cheers. As a note I run a "homemade" brass sensor holder. Pic #1 Cylinder Head Temp on a Yamaha XV1900. Pic #2 Cylinder Head Temp sensor is on the left as compared to a standard Coolant Temp sensor from a water cooled model.
Greg Field Posted February 10, 2009 Posted February 10, 2009 Sarah Palin wants you to put some hair-on sealskin between the sensor tip and what it is supposed to be sensing. Isn't that the kind of lesson we are supposed to have learned from the last 8 years in US government? What is supposed to be is actually the opposite of what we should expect? Why on Bush's green earth would you want an accurate reading of that which you need to read? It could only lead you to conclusions that don't result in maximum profits to Halliburton and such. I have to ask: What has become of sense in this whirled? Is everyone worldwide rendered brain-dead by the Cheney-Republican machine?
Guest ratchethack Posted February 10, 2009 Posted February 10, 2009 Why on Bush's green earth would you want an accurate reading of that which you need to read? WITHOUT RE-MAPPING, I b'lieve there's a good reason why most people (including Yours Truly) might NOT NECESSARILY want an accurate read, Greg -- at least without or until re-mapping. If you disagree with this, please advise: Most maps, both OE and custom, were created with the OE sensor/holder setup, which to a significant degree, determines the map. As such, these maps compensate (however inaccurately) for an inaccurate temp reading. If you introduce an accurately reading sensor/holder into a system with a map not created for it, this can throw the fuel metering off, and can make driveability worse. This seems to fit the symptoms I've observed by testing to "correct" the inaccuracy by direct thermal contact between both brass and plastic holders with the sensor via thermal compound, as posted above. Of course (as also noted above) the ideal setup here would be to install an accurately reading sensor/holder before creating a new custom map. Your take?
Dan M Posted February 10, 2009 Posted February 10, 2009 WITHOUT RE-MAPPING, I b'lieve there's a good reason why most people (including Yours Truly) might NOT NECESSARILY want an accurate read, Greg -- at least without or until re-mapping. Yes, exactly. I still contend the air cooled component is the issue. Head temps soar compared to their liquid cooled counterparts. That is not the time to lean further. I believe the plastic was spec'd for a reason just as the brass has fins on it. In all liquid cooled applications the sensor is screwed directly into the head (coolant) - They insulated it for a reason. Edit: Does any brand of map changing device allow to compensate for temp or just throttle position & RPM? What about the Wittner input? 1
raz Posted February 10, 2009 Posted February 10, 2009 Does any brand of map changing device allow to compensate for temp or just throttle position & RPM? I believe any piggyback solution (like the PCIII) is unable to change the temperature compensation tables. Anything that actually alters the maps inside the 15M ECU can do it, like Tuneboy, Directlink and whatever they are called. With Cliff's MyECU you have full control too.
Guest ratchethack Posted February 10, 2009 Posted February 10, 2009 What about the Wittner input? Per Greg's post yesterday, He's caring for his parents in Pennsylvania.
badmotogoozer Posted February 10, 2009 Posted February 10, 2009 I believe the plastic was spec'd for a reason just as the brass has fins on it. In all liquid cooled applications the sensor is screwed directly into the head (coolant) - They insulated it for a reason. Which is why I insulated my brass one with heavy PVC shrink. FWIW, making the sensor read temp accurately cured my mileage problem (drastic improvement) and also made the bike run like a dream.
GuzziMoto Posted February 10, 2009 Posted February 10, 2009 Dumbing a bike down in the name of making it run better. Why am I not surprised.
Guest ratchethack Posted February 10, 2009 Posted February 10, 2009 Dumbing a bike down in the name of making it run better. Why am I not surprised. Say GMoto -- adult remedial reading comprehension classes are offered in just about every community these days.
Dan M Posted February 10, 2009 Posted February 10, 2009 I believe any piggyback solution (like the PCIII) is unable to change the temperature compensation tables. So, it would follow that even with a custom map, it will only have accurate fueling at the temperature in which the map was done. If temperature compensation is too great or too little, there may still be trouble. From what I've witnessed, these bikes (pre feedback years) are pretty much all over the board it terms of stock a/f ratio. Way rich in some areas and way lean in others. And, it seems to vary from bike to bike. Some get decent mileage out of the box, some don't. Some ping, some don't. From what has been written here, some run better with the temp sensor left alone, some improve with the better contact. If your bike is inherently lean, making better contact with the temp sensor will make things worse. If it is rich, especially in the RPM & throttle opening range you favor, eliminating the gap or plastic will improve things. There are a few things here that are clear. The bikes were spec'd with a plastic holder. The plastic holder insulates the sensor from the head. Altering that head to sensor connection will change what the computer sees. Making a better physical connection between the sensor and the head will give a higher temp reading to the computer. A higher temp reading will lean the mixture.
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