DIY_EFI Digest Thursday, March 23 2000 Volume 05 : Number 119 In this issue: Bosch ECM circuit mods Re: O2 sensor question Re: O2 sensor question Re: O2 sensor question Re: Nissan EPROM Editor... Re: O2 sensor question Re: O2 sensor question Re: O2 sensor question Re: O2 sensor question Re: O2 sensor question Re: O2 sensor question Re: O2 sensor question Re: Nissan EPROM Editor... Re: O2 sensor question New bin file uploaded to incoming AXXD 1991 F-body Re: O2 sensor question Bosch ECM circuit mods (again) Re: O2 sensor question Re: O2 sensor question See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Thu, 23 Mar 2000 23:01:23 +1000 From: "Geoff, Kate & Theo Campbell" Subject: Bosch ECM circuit mods Does anyone know if it is possible to modify, or get information on how to modify, a Bosch LE-jetronic ECM (analogue). I have a basic diagram with component numbers & values, but don't know which ones change which variables. I am thinking along the lines of an early "programmable" (screwdriver) after-market unit and it's limited settings. - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 23 Mar 2000 07:06:38 -0600 From: "Dave & Irina Eicher" Subject: Re: O2 sensor question Thanks Chad, I'll look into this. dave - ----- Original Message ----- From: Chad To: Sent: Wednesday, March 22, 2000 3:08 PM Subject: Re: O2 sensor question > I found the other part numbers, it's an ACDelco sticker on top of the GM > sticker. > > I assume the ACDelco number is (there's a lot of numbers on the tag): > 1 #213-805 > And the GM number is: > 1 #9120292 > > I don't know how much they sell for, but it's a part you can get at any auto > parts store, not just from Bosch. > > Chad > > > >I don't know the exact engine, but it's on the 1999 model. It's a Bosch > >sensor, part # 0 258 006 065. I can get the GM part number also if you want. > > > >>Do you have an extact year, and engine?. > >>Grumpy > >> > >> > >>> The new model Cadillac Catera uses a wide band O2 sensor. This particular > >>> sensor needs a fairly sophisticated control loop to make it work though (I > >>> haven't worked with many others yet). I've seen it done analog, a bosch > >>unit > >>> we had in used opamps, but we decided to go digital. We used a > >>microcontroller > >>> to control the heater (it has to be the right temperature to be accurate), > >>> check the O2 level, and communicate with the A/F display (in our case, a > >>PC). > >>> > >>> chad > >>> > >>> >Haven't investigated sensors yet, I was hoping to find one that came with > >>a > >>> >spec so I could see what the output curve is, then read with an ADC and > >>> >micro, display on a little LCD. Do you know of a low cost source for > >>these > >>> >wideband sensors? > >>> > > >>> >dave > > > -------------------------------------------------------------------------- - -- > To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) > in the body of a message (not the subject) to majordomo@xxx.org > > - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 23 Mar 2000 07:13:25 -0600 From: "Dave & Irina Eicher" Subject: Re: O2 sensor question How did you learn what sensor output translates to what AFR? Do you have a spec on the sensor? That's what I'm look for too, a sensor and a spec, thinking I could figure out a way to read it and make use of it. thanks, dave - ----- Original Message ----- From: Chad To: Sent: Wednesday, March 22, 2000 10:28 AM Subject: Re: O2 sensor question > The new model Cadillac Catera uses a wide band O2 sensor. This particular > sensor needs a fairly sophisticated control loop to make it work though (I > haven't worked with many others yet). I've seen it done analog, a bosch unit > we had in used opamps, but we decided to go digital. We used a microcontroller > to control the heater (it has to be the right temperature to be accurate), > check the O2 level, and communicate with the A/F display (in our case, a PC). > > chad > > >Haven't investigated sensors yet, I was hoping to find one that came with a > >spec so I could see what the output curve is, then read with an ADC and > >micro, display on a little LCD. Do you know of a low cost source for these > >wideband sensors? > > > >dave > > > > > -------------------------------------------------------------------------- - -- > To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) > in the body of a message (not the subject) to majordomo@xxx.org > > - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 23 Mar 2000 08:28:22 -0500 From: "nacelp" Subject: Re: O2 sensor question $197.54 for the gm number. Too much for me to play with Grumpy Hurrryyyyyy up Gar., I'm dieing here........................ > I found the other part numbers, it's an ACDelco sticker on top of the GM > > sticker. > > > > I assume the ACDelco number is (there's a lot of numbers on the tag): > > 1 #213-805 > > And the GM number is: > > 1 #9120292 > > > > I don't know how much they sell for, but it's a part you can get at any > auto > > parts store, not just from Bosch. - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Fri, 24 Mar 2000 02:29:58 From: "Mike (Perth, Western Australia)" Subject: Re: Nissan EPROM Editor... At 11:30 AM 22/3/2000 -0600, you wrote: >Did everyone that requested the Nissan EPROM Editor I had get it to work OK? Sorry ? Are you saying *you* got a Nissan Eprom editor to work OK, I'm looking to edit/upgrade the eprom in an ECU for a Nissan engine, any ideas ? Rgds ~`:o) Mike Massen Trading as "Network Power Systems" and "Network Computers" Perth, Western Australia Ph +61 8 9444 8961 Fx +618 9264 8229 (fax -> email) Products/Personal/Client web area at http://www.wantree.com.au/~erazmus (Current pics - trip to Malaysia to install equipment in jungle power site) Some say there is no magic but, all things begin with thought then it becomes academic, then some poor slob works out a practical way to implement all that theory, this is called Engineering - for most people another form of magic. - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Fri, 24 Mar 2000 03:02:33 From: "Mike (Perth, Western Australia)" Subject: Re: O2 sensor question At 11:07 AM 22/3/2000 -0800, garwillis@xxx.com (Garfield Willis) wrote: >For those unfamiliar, "EGOR-the-module" is an interface for a >current-pump-style NTK-Honda 5-wire wideband sensor, basically it's a >black-box with pins, around which you'll be able to build a >WOT/wideband-O2 engine manager; and "EGOR-the-meter" is a hand-held >precision AFR meter with large digital and bar-graph display (and an >analog out for logging, of course), useful for tuning/cal work. Are there any specs for the sensor ? I'd like to integrate the display into my own equipment, Tah Rgds :) Mike - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 23 Mar 2000 14:45:19 -0500 From: "nacelp" Subject: Re: O2 sensor question There is a ton of info., about WB sensors, yep, in the archives. Grumpy > >For those unfamiliar, "EGOR-the-module" is an interface for a > >current-pump-style NTK-Honda 5-wire wideband sensor, basically it's a > >black-box with pins, around which you'll be able to build a > >WOT/wideband-O2 engine manager; and "EGOR-the-meter" is a hand-held > >precision AFR meter with large digital and bar-graph display (and an > >analog out for logging, of course), useful for tuning/cal work. > > Are there any specs for the sensor ? > > I'd like to integrate the display into my own equipment, > > Tah > > Rgds > > :) Mike > - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 23 Mar 2000 11:56:17 -0800 From: garwillis@xxx.com (Garfield Willis) Subject: Re: O2 sensor question On Wed, 22 Mar 2000 13:18:18 -0700, "Chad" wrote: > The new model Cadillac Catera uses a wide band O2 sensor. This particular > sensor needs a fairly sophisticated control loop to make it work though (I > haven't worked with many others yet). I've seen it done analog, a bosch > unit we had in used opamps, but we decided to go digital. We used a > microcontroller to control the heater (it has to be the right temperature to be accurate), > check the O2 level, and communicate with the A/F display (in our case, a PC). I've just been ruminating about this, and I wonder if this isn't another *variant* of the older LSM-11 style showing up once again. I know that Bosch does have a current-pump sensor (the "LSU"), but didn't think it's been deployed in cars yet. It's used in Bosch's LA-3 Lambda Meter, tho. BTW, these older types of sensors are referred to by Bosch and others as "Nernst" type (sometimes also described as "switching" type if a generic ordinary, because of their high non-linearity and an ECU's normal use of them to merely find the stoich "switch-crossing"), to distinguish them from the current-pump styles like the LSU and the NTK's, which have both a Nernst cell and a pumping cell; hence they are referred to by their possession of the additional O2 pump). So, do you remember Chad how many wires the sensor you mention above had, or if it had an O2 pump? If just the 4, that could explain why the careful control of the heater, because ... One thing I don't remember anyone pointing out/observing, is that this sophistication for the heater *control* is needed because the Bosch heaters all seem to have negative tempco's, meaning the resistance of the heater core goes DOWN as the temp goes up, so things can get carried away without tight controls over the heater current. The NTK-derived sensors (at least the current-pump styles) all have heaters with positive tempco's (resistance goes UP as temp goes up), so they are inherently self-regulating to a large degree. This is why the NTK papers show that even with a +BATT swing from 10V to 15V along one axis, a 600-950 degC tip temp swing along the other axis, still the change is within +-0.15 AFR. By way of contrast, the same schmoo of variables on the Bosch 4-wire "wider-band" sensors (non-current-pump style) would give you at least a couple WHOLE AFRs of variation. The heater resistance alone goes down by over an order of magnitude between 650-900 degC on the Bosch's, this according to their own specs on the LSM-11. Without factoring in this temperature dependance during measurements, they'd be useless on the rich side, where this effect is strongest with the LSMs. Their specs show without this temp compensation, over the range 650-900 degC, the temp effects alone would completely swamp the full scale measurement range (from stoich to say 10AFR). So anyone building meters or controllers around these sensors per force MUST include both temp compensation and heater control. This had been discussed a year or so by Frank Parker, it's just that I don't recall the issue of "the tempco's being negative" being a factor in needing both temp compensation AND tight control of the heater, ever being mentioned. Thankfully, neither of these steps is required for the NTK-derived sensors. You CAN apparently cut down the +-0.15 AFR slop significantly by regulating the heater voltage, and some AFR instrument companies do this, but it seems like way overkill to attempt to achieve greater than 1.0-1.5% accuracy. Too many other factors, including the electronics, begin to intrude. Even the LA-3 meter's specs claim no more than a +-1.5% "measurement tolerance" as they style it. It's somewhat surprising (if my surmisal above is correct) that both OEMs and aftermarket meter makers may be trying to get the cost down, by opting for using these older type sensors. But the way NTK had locked up the meter market with their exclusive arrangement with Horiba, coupled with Bosch being VERY late in developing their own current-pump style sensor (Honda-NTK deployed theirs in autos in '90, Bosch didn't have the LA-3/LSU ready until '97 IIRC), this could be more a business than a technical decision. One other thing to mull over, tho. The Nernst-style sensors, at least the LSM-11, would appear to maybe have a higher tolerance/lifetime in the presence of lead. In fact, remember Bosch marketed them first as their "lead-tolerant" O2 sensor. Horiba, for example with their Lambda Checker box (which uses an NTK sensor) suggests a sensor lifetime of just 20hrs! in a "poisonous environment", which they refer to as exposure to either lead or high oil consumption. This may suggest a certain relative fragility, if you will, with the current-pump type sensors. Only time and field experience will tell. I know that Frank and his motorsport team have been using NTK boxes in the presence of lead, and IIRC haven't seen any real early mortality in their sensors, so maybe Horiba's spec is just intended as a cautionary to scare off, and also cover their warranty's butt. Just some thots (and maybe exhaust gas :) along the way. Gar - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 23 Mar 2000 12:46:18 -0800 From: garwillis@xxx.com (Garfield Willis) Subject: Re: O2 sensor question On Fri, 24 Mar 2000 03:02:33, "Mike (Perth, Western Australia)" wrote: >At 11:07 AM 22/3/2000 -0800, garwillis@xxx.com (Garfield Willis) wrote: > >>For those unfamiliar, "EGOR-the-module" is an interface for a >>current-pump-style NTK-Honda 5-wire wideband sensor, basically it's a >>black-box with pins, around which you'll be able to build a >>WOT/wideband-O2 engine manager; and "EGOR-the-meter" is a hand-held >>precision AFR meter with large digital and bar-graph display (and an >>analog out for logging, of course), useful for tuning/cal work. > >Are there any specs for the sensor ? > >I'd like to integrate the display into my own equipment, > >Tah Hey, one thing I gotta know...what's this "tah" interjection you often use, mean in WestOz? Is it like a grin, or a "heh heh" or "hee hee" like we do in the States? I've never seen it before and kinda appreciate the general Aussie verbal style, so I had to ask. If it's difficult (or embarrassing) to convey via public typing, don't sweat it. Anyway, on to your question. This has been explained before, but this type of sensor (the Honda-NTK sensor is one of the so-called "current-pump" types) REQUIRES a special sort of interface electrics to go with it. It's not merely a passive sensor like the older "Nernst" or switch type sensors, which just put out a voltage you read. There's a little pump inside these new sensors that squirts oxygen ions into (or out of) another measurement cell, in an attempt to balance out excess or depletion of oxygen in the exhaust gas. This clever trick is what allows these sensors to be so "linear" and good as O2 measurement devices, but makes operating the sensor more complicated than the older type. EGOR *is* that special interface electrics. If you want to roll your own display, you could use just an EGOR-module, and build your own instrument around that, but when you see how snarky and inexpensive our EGOR-meter is going to be, you'll probly just go for that instead. This discussion allows me to add another comment/recommendation about how to plan for using these sensors. Ya know, they're all still pretty spendy, even with the Honda sensor available with a goodly discount over the net for slightly less than $100, that's still a pretty decent chunkOchange for "consumables". I would think twice about planning on having such a sensor left in the exhaust ALL the time, and part of your normal everyday panel meters. Everybody knows that rich running, oil burning, and lead mix all contribute to shorter lifetimes for these sensors. Add to that the fact that any heated sensor has a VERY hot ceramic bit in them that can be instantly fractured if clobbered by a errant drop of water from a cold exhaust system. All it takes is condensation in the wrong place, a (perhaps unbeknownst to you) poorly chosen placement of the O2 bung, and all these things may put you in the position of test engineer where the supplies of sensors is paid for out of your own pocket. The auto mfgs. found out about those types of mistakes and paid for them (usually, hopefully) during engineering trials. You might want to avoid those costs if possible. Sure, you're gonna go for it if you're planning on a WOT/wideband ECU, because you don't have any choice, and you need that WOT tight control to get your track times down, or whatever. But if you're using it for tuning and tweaking your open-loop fuel maps in your EFI controller from time to time, I'd suggest you consider it a hand-held instrument that you use via a tail-pipe probe, and you only expose the sensor to these attendant dangers whenever you need to be performing those kinds of measurements. On the front panel of the EGOR-meter right below the ON switch, you're gonna see a litany of cautions (like a pilot's checklist, if you will) to help you avoid damaging the sensor, just because the bloody things still cost $100, and in most places that can still buy a nice dinner for two. But of course, it's everyone's choice. I'm just trying to point out some realities of the situation. Everything possible has been done to keep the deployment of this cool measurement technology as absolutely low-cost as possible. So the clients we're targeting we just ASSUME will want to be very careful with their sensors and baby them. But if your gameplan (e.g., WOT controller) or robust pocket change allows it, sure go for a permanent wideband sensor in your exhaust full-time, and use an EGOR-module to interface that sensor to your own custom electrics. That is one of the uses it's intended for, except we think mostly for both economy and appreciating the finer things in life, if you're not building an engine manager, you'll probably find our meter irresistible. :) But like I said before, both the module and meter are going to be very affordable, so the choice will be yours. Gar - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 23 Mar 2000 14:23:21 -0700 From: "Chad" Subject: Re: O2 sensor question > >So, do you remember Chad how many wires the sensor you mention above >had, or if it had an O2 pump? If just the 4, that could explain why the >careful control of the heater, because ... > This is one of the full blown five wire O2 sensors. If you can get ahold of the technical information on it from Bosch (Dave: this is where to get the info you want if they will send it to you), they have some response graphs that characterize the O2 content based on the current coming from the sensor. The bias conditions for these graphs include temperature and reference voltage. This is why we needed to control the heater so closely (even though it does have a positive temperature coefficient). Sure, the heater is self regulating in that it won't get into a thermal runaway situation, but the drifts in temperature mess up the accuracy of the measurement relative to the graphs. Maybe you can teach me a little bit about the terminology. This sensor either draws or sources current if the mixture is above or below stoichiometric, is this what a 'current-pump' type sensor is? - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 23 Mar 2000 14:05:40 -0800 From: garwillis@xxx.com (Garfield Willis) Subject: Re: O2 sensor question On Thu, 23 Mar 2000 14:23:21 -0700, "Chad" wrote: >This is one of the full blown five wire O2 sensors. If you can get ahold of >the technical information on it from Bosch (Dave: this is where to get the info >you want if they will send it to you), they have some response graphs that >characterize the O2 content based on the current coming from the sensor. The >bias conditions for these graphs include temperature and reference voltage. >This is why we needed to control the heater so closely (even though it does >have a positive temperature coefficient). Sure, the heater is self regulating >in that it won't get into a thermal runaway situation, but the drifts in >temperature mess up the accuracy of the measurement relative to the graphs. Understood. Since this is at least like the LSU if not in fact the LSU, this explains why even the LA-3 has to use a PID controller on the heater. Much more sensitive to temp and heater drive than the NTKs then. It's important to have both a positive tempco, as well as the right tempco that gives best self-regulation. I really wonder why on earth Bosch ever made ANY that had a negative tempco. Puzzling; maybe the right materials weren't available earlier. >Maybe you can teach me a little bit about the terminology. This sensor either >draws or sources current if the mixture is above or below stoichiometric, is >this what a 'current-pump' type sensor is? Normally I would say "yes, exactly". The oxygen pump is operated by a pumping current, whose polarity is determined by either depleted or excess O2, and whose current level relates to the amount of depletion or excess, hence your curves. But from the description, I may be jumping to some conclusions. You mention "bias conditions" and a reference voltage; it sounds like those are set and the resultant current is measured. On the face of it, this sounds a bit different than the way the NTKs work. The NTKs require a feedback loop which the current pump is part of, and which is servo'd off the nernst measurement cell. As such, there isn't any biasing or reference per se. But here again, I might be leaning on words too heavily. They may infact work very similar and I'm just getting hung up on the terminology meself. Gar - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 23 Mar 2000 17:26:56 -0500 From: "nacelp" Subject: Re: O2 sensor question Makes ya wonder if they are tired about the bad press about slow erratic warm ups, and maybe a cure (or attempt at curing that). Grumpy > Understood. Since this is at least like the LSU if not in fact the LSU, > this explains why even the LA-3 has to use a PID controller on the > heater. Much more sensitive to temp and heater drive than the NTKs then. > It's important to have both a positive tempco, as well as the right > tempco that gives best self-regulation. I really wonder why on earth > Bosch ever made ANY that had a negative tempco. Puzzling; maybe the > right materials weren't available earlier. - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 23 Mar 2000 15:54:51 -0700 From: "Programmer" Subject: Re: Nissan EPROM Editor... Geez--that's one I missed...do you still have another copy ?? Lyndon nwester@xxx.org - -----Original Message----- From: BOWEN, SCOTT M. (JSC-CC) To: 'DIY_EFI@xxx.org> Date: March 22, 2000 10:47 AM Subject: Nissan EPROM Editor... >Did everyone that requested the Nissan EPROM Editor I had get it to work OK? > > >Scott Bowen >Bastard Motorsports Engineering >Houston, TX >281-244-9669 >--------------------------------------------------------------------------- - - >To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) >in the body of a message (not the subject) to majordomo@xxx.org > - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 23 Mar 2000 17:14:03 -0700 From: "Chad" Subject: Re: O2 sensor question >Normally I would say "yes, exactly". The oxygen pump is operated by a >pumping current, whose polarity is determined by either depleted or >excess O2, and whose current level relates to the amount of depletion or >excess, hence your curves. But from the description, I may be jumping to >some conclusions. You mention "bias conditions" and a reference voltage; >it sounds like those are set and the resultant current is measured. On >the face of it, this sounds a bit different than the way the NTKs work. >The NTKs require a feedback loop which the current pump is part of, and >which is servo'd off the nernst measurement cell. As such, there isn't >any biasing or reference per se. But here again, I might be leaning on >words too heavily. They may infact work very similar and I'm just >getting hung up on the terminology meself. > >Gar > You're right about the reference voltage. A precision reference voltage is applied, the correct temperature is set up, then the resulting current is measured. The control loop is set up to measure the voltage drop across the heater to check it's temperature (adjusting if necessary), then measuring the resulting current for O2 content. Technically, I do think I misused the term 'bias conditions', what I mean to imply are the operating conditions that the Bosch graphs are based upon. Admittedly, I don't understand what the reference voltage does, I just know that it needs to be there. In the interest of learning, I'm going to try to find some more info about the physical construction of this sensor. It is my first guess that the reference voltage is used to extract a given number of oxygen atoms from the chamber, and the polarity and magnitude of the current needed to pump oxygen back into equilibrium indicates the O2 concentration in the chamber. This is probably a hasty conclusion, but I would really like to learn *exactly* what is going on. Any insight from how NTKs work? Chad - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 23 Mar 2000 18:38:03 -0600 From: "Dan Plaskett" Subject: New bin file uploaded to incoming AXXD 1991 F-body FWIW Just uploaded AXXD.bin to incoming. It is the stock chip for a 1991 F-body, 305 with 5 speed manual transmission. Enjoy. Dan Plaskett - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 23 Mar 2000 17:44:02 -0800 From: garwillis@xxx.com (Garfield Willis) Subject: Re: O2 sensor question On Thu, 23 Mar 2000 17:14:03 -0700, "Chad" wrote: >You're right about the reference voltage. A precision reference voltage is >applied, the correct temperature is set up, then the resulting current is >measured. The control loop is set up to measure the voltage drop across the >heater to check it's temperature (adjusting if necessary), then measuring the >resulting current for O2 content. Technically, I do think I misused the term >'bias conditions', what I mean to imply are the operating conditions that the >Bosch graphs are based upon. Sounds close enough to me, technobabble isn't as precise a vocabulary as we're led to believe, anyway :); the drift I got is what you've detailed above, and based on that, it does seem that this sensor, while perhaps operating on similar principles, has some distinct differences from the NTKs. Interesting. >Admittedly, I don't understand what the reference voltage does, I just know >that it needs to be there. In the interest of learning, I'm going to try to >find some more info about the physical construction of this sensor. It is my >first guess that the reference voltage is used to extract a given number of >oxygen atoms from the chamber, and the polarity and magnitude of the current >needed to pump oxygen back into equilibrium indicates the O2 concentration in >the chamber. This is probably a hasty conclusion, but I would really like to >learn *exactly* what is going on. Any insight from how NTKs work? The most detailed info on the NTK sensors is found in their SAE paper #920234, but I think you're going to find that your Bosch gizmo there works in a somewhat different manner. Doesn't Bosch ever publish about devices like this? I don't recall anyone ever mentioning a paper on the LSMs either. Gar - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Fri, 24 Mar 2000 13:10:09 +1000 From: "Geoff, Kate & Theo Campbell" Subject: Bosch ECM circuit mods (again) Sorry for repeating myself, mail got lost. So... Does anyone know if it is possible to modify, or get information on how to modify, a Bosch LE-jetronic ECM (analogue). I have a basic diagram with component numbers & values, but don't know which ones change which variables. I am thinking along the lines of an early "programmable" (screwdriver) after-market unit and it's limited settings. - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Thu, 23 Mar 2000 19:39:26 -0800 From: garwillis@xxx.com (Garfield Willis) Subject: Re: O2 sensor question On Thu, 23 Mar 2000 14:05:40 -0800, garwillis@xxx.com (Garfield Willis) wrote: >Since this is at least like the LSU if not in fact the LSU, >this explains why even the LA-3 has to use a PID controller on the >heater. Geez, whadaputz I am. I just realized/remembered that a chap posted a question on where to get some of these, called them LSU sensors, and gave the exact same part number as Chad. This other guy's post was around two weeks ago. Sheesh, can you say "loss of short-term memory"? So that seems to confirm that the LSU sensor is indeed available and deployed in at least one car. Amazing; time marches on! Here's the guys original post: On Tue, 7 Mar 2000 16:48:12 -0800, "Jacky Chu" wrote: >Does anyone one know of any place that sells the Bosch LSU O2 sensor. >The marking on the sensor said: > >LSU 4 966011 >0 258 006 065 020 > >I am looking to buy 5 to 10 of them for replacement part on our dyno. > >Sorry that this is not efi related. but I figure this would be the place to >find such information. >I looked through the archives already, but didn't find anything. > >thanks, > >Jacky Chu >Yoshimura R&D of America >www.yoshimura-rd.com - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Fri, 24 Mar 2000 12:28:41 From: "Mike (Perth, Western Australia)" Subject: Re: O2 sensor question At 12:46 PM 23/3/2000 -0800, garwillis@xxx.com (Garfield Willis) wrote: >>Are there any specs for the sensor ? >> >>I'd like to integrate the display into my own equipment, >> >>Tah > >Hey, one thing I gotta know...what's this "tah" interjection you often >use, mean in WestOz? Is it like a grin, or a "heh heh" or "hee hee" like >we do in the States? I've never seen it before and kinda appreciate the >general Aussie verbal style, so I had to ask. If it's difficult (or >embarrassing) to convey via public typing, don't sweat it. hehe - LOL :) Well its mostly an English slang for a friendly "Thanks", seems to have been adopted generally in Oz, given our large intake of Poms (English immigrants). Generally when you've lived here for a while one tends to get casual about communications - not just on email, most ozzies don't stand too much on ceremony or protocol (except when the queen visits;) [The real sweaty stuff I leave for my GF ;-] >Anyway, on to your question. This has been explained before, but this >type of sensor (the Honda-NTK sensor is one of the so-called >"current-pump" types) REQUIRES a special sort of interface electrics to >go with it. It's not merely a passive sensor like the older "Nernst" or >switch type sensors, which just put out a voltage you read. There's a >little pump inside these new sensors that squirts oxygen ions into (or >out of) another measurement cell, in an attempt to balance out excess or >depletion of oxygen in the exhaust gas. This clever trick is what allows >these sensors to be so "linear" and good as O2 measurement devices, but >makes operating the sensor more complicated than the older type. Where does the platinum type Bosch O2 sensor come into this, is that the Nernst type you mention ? >EGOR *is* that special interface electrics. If you want to roll your own >display, you could use just an EGOR-module, and build your own >instrument around that, but when you see how snarky and inexpensive our >EGOR-meter is going to be, you'll probly just go for that instead. mmm OK - interesting - please update me as soon as you can on your product, :) >This discussion allows me to add another comment/recommendation about >how to plan for using these sensors. Ya know, they're all still pretty >spendy, even with the Honda sensor available with a goodly discount over >the net for slightly less than $100, that's still a pretty decent >chunkOchange for "consumables". I would think twice about planning on >having such a sensor left in the exhaust ALL the time, and part of your >normal everyday panel meters. Everybody knows that rich running, oil >burning, and lead mix all contribute to shorter lifetimes for these >sensors. Add to that the fact that any heated sensor has a VERY hot >ceramic bit in them that can be instantly fractured if clobbered by a >errant drop of water from a cold exhaust system. All it takes is >condensation in the wrong place, a (perhaps unbeknownst to you) poorly >chosen placement of the O2 bung, and all these things may put you in the >position of test engineer where the supplies of sensors is paid for out >of your own pocket. The auto mfgs. found out about those types of >mistakes and paid for them (usually, hopefully) during engineering >trials. You might want to avoid those costs if possible. mmmm - I'd like to know where I could buy a sensor off the net, our local parts dealers seem to add about 300% markup (on anything) and then another 100% if its anything technical or elctronic :( >Sure, you're gonna go for it if you're planning on a WOT/wideband ECU, >because you don't have any choice, and you need that WOT tight control >to get your track times down, or whatever. But if you're using it for >tuning and tweaking your open-loop fuel maps in your EFI controller from >time to time, I'd suggest you consider it a hand-held instrument that >you use via a tail-pipe probe, and you only expose the sensor to these >attendant dangers whenever you need to be performing those kinds of >measurements. On the front panel of the EGOR-meter right below the ON >switch, you're gonna see a litany of cautions (like a pilot's checklist, >if you will) to help you avoid damaging the sensor, just because the >bloody things still cost $100, and in most places that can still buy a >nice dinner for two. But of course, it's everyone's choice. I'm just >trying to point out some realities of the situation. Everything possible >has been done to keep the deployment of this cool measurement technology >as absolutely low-cost as possible. So the clients we're targeting we >just ASSUME will want to be very careful with their sensors and baby >them. But if your gameplan (e.g., WOT controller) or robust pocket >change allows it, sure go for a permanent wideband sensor in your >exhaust full-time, and use an EGOR-module to interface that sensor to >your own custom electrics. That is one of the uses it's intended for, >except we think mostly for both economy and appreciating the finer >things in life, if you're not building an engine manager, you'll >probably find our meter irresistible. :) But like I said before, both >the module and meter are going to be very affordable, so the choice will >be yours. Ok thats for that - interesting, I suppose it would be almost as good and cheaper to go for two conventional sensors. One before and one after the cat and do a bit of maths, Tah, Toodle loo cyah :) mike - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ End of DIY_EFI Digest V5 #119 ***************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. A non-digest (direct mail) version of this list is also available; to subscribe to that instead, replace "diy_efi-digest" in the command above with "diy_efi".