DIY_EFI Digest Tuesday, March 28 2000 Volume 05 : Number 127 In this issue: RE: DIY_EFI Digest V5 #126 Re: O2 sensor response times-wide ratio catalyst Re 8051 EFI Re: O2 sensor response times Re: DIY-EFI's Funny 'reply all' Re: O2 sensor response times Re: DIY-EFI's Funny 'reply all' RE: aftermarket ecu etc... Re: O2 sensor response times- catalyst Re: Re 8051 EFI RE: O2 sensor response times Re: O2 sensor response times Re: aftermarket ecu etc... Re: O2 sensor response times- catalyst Re: O2 sensor response times Diacom cable Looking for pulse output MAF Re: Cheap Protection ... The circuit Re: Diacom cable Re: O2 sensor response times- catalyst Re: DIY-EFI's Funny 'reply all' Re: DIY-EFI's Funny 'reply all' Re: DIY-EFI's Funny 'reply all' See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Tue, 28 Mar 2000 07:32:36 -0700 From: "Van Setten, Tim (AZ75)" Subject: RE: DIY_EFI Digest V5 #126 > Date: Tue, 28 Mar 100 12:38:36 +0800 (WST) > From: Bernd Felsche > Subject: Re: Fuel pressure waring light > > mike mager writes: > > >Clint S. said: > > >>I would like to install a fuel pressure idiot light, I have a turbo and > >>would like to know if pressure drops off at high boost . > [Van Setten, Tim (AZ75)] We have tried this in our off road cars and found that by the time the light goes off, it's too late! Under boost you don't want to lean out. So, what you really want to monitor is the return to the tank. When the return line starts to "Dry Up", that's when the pump is not keeping up. If you think about it, the return will stop Before the pressure drops. There are some sensors that will trip a warning light under a specified flow. Once you know that, then it's easy to boost the voltage to the pump to keep things going. Hope this helps...Tim. - ---------------------------------------------------------------------------- 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: Tue, 28 Mar 2000 10:47:28 -0500 From: Will McGonegal Subject: Re: O2 sensor response times-wide ratio catalyst We have an NTK wide ratio O2 sensor here at our lab. We will have to be using it for an upcoming project on the dyno, so we wanted to determine how it functioned. My colleague Jim have been looking into this and he dug up some info this morning that explained a lot and it indicates that there can be a catalytic reaction taking place in the sensor. As discussed in previous posts, the NTK wide ratio sensor sensor has three parts, heater, O2 sensor and O2 "pump". The O2 pump can move O2 towards or away from the sensor cell. The amount of current run through the pump (positive or negative) determines how much O2 is pumped to or away from the sensor. The idea is to keep the sensor outputting 0.450 V (stoich, complete combustion). If the engine is running lean (excess O2) the sensor output starts to fall and the O2 pump removes the excess O2 from the small amount of exhaust in the O2 sensor cell, in an attempt to maintain a 0.450 V sensor voltage. How much O2 you remove (you know this by the current running through the pump) can be used to determine the AFR. If the engine is running rich (excess hydrocarbons), the sensor output voltage rises so the pump moves O2 towards the sensor. There is platinum in there to promote a reaction between the unburned HC and O2. How much O2 is added (pumping current) to maintain the sensor 0.450 V stoich setting is used to determine what the AFR is. Oh, you also need to factor in the Hydrogen to Carbon ratio of the fuel and whether the fuel is oxygenated (e.g.: alcohol) to get accurate AFR readings. So yes, there is a catalytic reaction taking place in the sensor when the engine is running rich. Essentially the O2 pump is used to keep the exhaust stoich (450 mv) in the tiny region of the sensor. That's my understanding of it. Will > ------------------------------ > > Date: Mon, 27 Mar 2000 18:27:41 -0800 > From: garwillis@xxx.com (Garfield Willis) > Subject: Re: O2 sensor response times > > On Mon, 27 Mar 2000 17:35:30 -0800 (PST), Orin wrote: > > >Heywood pg 301: "Equilibrium is established in the exhaust gases > >by the catalytic activity of the platinum metal electrodes." > > > >So yes, there are other reasons. > > Yes, but that's in a place where contact of the platinum with the > exhaust gases catalyzes/oxidizes the HC and CO gas components (namely, > in a CAT). Are you saying that this effect is part of the operation of > the O2 sensor? If so, it's never mentioned in any of the papers AFAIK. - ---------------------------------------------------------------------------- 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: Tue, 28 Mar 2000 08:11:42 -0800 From: "John Dammeyer" Subject: Re 8051 EFI Hi Paul, You can do a capable Fuel Injection system with a 8051 variant that includes CD Ignition for a four cylinder Engine. I used the Philips 80C592 with built in CAN running at 16MHz. If you check out my WEB site at http://www.autoartisans.com/ign-pic.htm you will see a description and a few photos describing the progress. There is still more to do on this project which includes a new Dashboard PC program that shows dual engine status at the same time and adds far more error reporting and diagnostics. (We've had some problems). I'm thinking of doing a six cylinder version for my Jeep Cherokee since the 1987 Jeep was the first one with the inline Six and Fuel Injection and it lets me try a Six Cylinder engine in preparation for six cylinder Lycoming Aircraft Engines. For the six cylinder I'll switch over to a C167C processor which means a new compiler etc. If the client doesn't fund this I may just do the design myself (and therefore own the board design) and make the board available to the DIY-EFI group. Cheers, John Dammeyer > > > > > When I subscribed to the '332 list, I was just a bit too late into the > >'332 project, and by the time I had thought it over, the group buy was > >closed. Is yours oriented to a four-cylinder engine? I really need to do > >some planning on the whole EFI matter! I drive a carb'd vehicle - with an > >integral intake manifold! - so hacking an ECM on my 'daily driver' is out. > > > My 'big project' engine is not even in hardware yet (design only). > >Maybe I do want to scratch-build my own; wouldn't be 'better' than any > >other, but it would be optimised for my application (yeah, right, buddy), > >and I would know the 'why' of every little detail. Some of us have a drive > >to do that! (you know) > - ---------------------------------------------------------------------------- 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: Tue, 28 Mar 2000 10:27:55 -0600 From: Gary Peyton Subject: Re: O2 sensor response times Well....OK. I'm a physical chemist. And I can tell you for sure that while platinum may help some kind of electrical contact for something, it's there primarily as a catalyst. In chemistry, if you want to catalyse something and you dont know how, you use platinum. Its great for reductions and oxidations, and just about everything else. What I dont know, is what the specific reactions are that are generating the voltage, because its not just "all of 'em". But I'll bet that is not too difficult to find out. [short off-topic introductory section :] Actually in my research group we study reactions very similar to combustion reactions, but we do it in water, at room temperature, to destroy pollutants. We study kinetics (how fast?) and mechanisms (what detailed chemical pathway?) of these reactions, to make info, conclusions, and calculational tools available so cleaner, cheaper pollution cleanup processes can be designed. [told you it was short] I'll see what I can find out so maybe I can pay a little lurking dues. Gary Peyton At 06:27 PM 03/27/2000 -0800, you wrote: >On Mon, 27 Mar 2000 17:35:30 -0800 (PST), Orin wrote: > >>Heywood pg 301: "Equilibrium is established in the exhaust gases >>by the catalytic activity of the platinum metal electrodes." >> >>So yes, there are other reasons. > >Yes, but that's in a place where contact of the platinum with the >exhaust gases catalyzes/oxidizes the HC and CO gas components (namely, >in a CAT). Are you saying that this effect is part of the operation of >the O2 sensor? If so, it's never mentioned in any of the papers AFAIK. > >But since I've admitted I'm a total putz in this electrochemical realm, >I CAN see how the fact that gas components (H, HC, CO) seem to like >platinum, certainly might dispose it for use as the outer electrodes. >It's just that this is not the area normally mentioned where the >recombination of oxygen ions with the gas components occurs, which >affects the pumping current. It's always depicted as occuring in the >porous ZrO2 portion, where the oxy ions are either removed or supplied >to the sample of exhaust gas. But then again, these devices are referred >to as galvanic cells, which generally require dissimilar >metals/semiconductors. So does that mean the ZrO2 is one such material, >and the platinum makes up the other "plates" of this sorta battery. >Ouch, my head is beginning to hurt; if only I'd payed attention in >Chemistry class. > >I know there is at least one physical chemist lurking behind the >curtain; maybe you could lift the veil on this stuff for us, eh? > >TIA, >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 > ====================================================================== Gary R. Peyton Senior Professional Scientist Watershed Science Section Illinois State Water Survey Illinois Department of Natural Resources (217) 333-5905 FAX (217) 333-6540 =================================================================== - ---------------------------------------------------------------------------- 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: Tue, 28 Mar 2000 10:30:06 -0600 From: steve ravet Subject: Re: DIY-EFI's Funny 'reply all' Peter Gargano wrote: > > More to the point - Who is Hektor Valesh? Jon Valesh hosts our new WWW server. Hektor is the machine that runs the list. I've never seen a computer with a first and last name before... > > Ade + Lamb Chop wrote: > > > Why is it that with DIY-EFI when I click my 'reply to all' button in my > > mailer I reply to diy-efi twice rather than the original sender and > > diy-efi? I am a member of another this and that is fine... Why is it > > different for diy-efi? Doesn't do that for me, maybe it's something with your mail client. Try using regular reply instead of reply all. - --steve - -- Steve Ravet steve.ravet@xxx.com ARM,Inc. www.arm.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: Tue, 28 Mar 2000 10:42:11 -0600 From: steve ravet Subject: Re: O2 sensor response times Gary Peyton wrote: > > Well....OK. > > I'm a physical chemist. Gary's also a sharp shooter from three point land, and plays suffocating defense. Wait, maybe I'm thinking of someone else... - --steve - -- Steve Ravet steve.ravet@xxx.com ARM,Inc. www.arm.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: Tue, 28 Mar 2000 09:01:02 -0800 (PST) From: "Jon V." Subject: Re: DIY-EFI's Funny 'reply all' On Tue, 28 Mar 2000, Peter Gargano wrote: > More to the point - Who is Hektor Valesh? Hey! Don't you know Hektor V.? Or was this one of those "who is Kaiser Soze?" type questions? Ade + Lamb Chop wrote: > Why is it that with DIY-EFI when I click my 'reply to all' button in my > mailer I reply to diy-efi twice rather than the original sender and > diy-efi? I am a member of another this and that is fine... Why is it > different for diy-efi? Doesn't do that for me... what mailer are you using? - -Jon - ---------------------------------------------------------------------------- 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: Tue, 28 Mar 2000 09:31:18 -0800 From: "Randall" Subject: RE: aftermarket ecu etc... "Toby Atwater" wrote : > > > This is for my onboard PC project. I originally thought of > turning a PC into > a ECU but then I just realized that depending on either a > Microsoft OS or > either another OS to run your car was a bad thing. Blue > screen of death > would probably cause you to roll to a stop and start cursing. > Also I just > wasnt sure of any of the OSes are real time, could they be fast enough > inorder to keep up at 9000 rpm. Toby : I don't advocate this approach, but there _are_ inexpensive, realtime, reliable OSes that will run on PC hardware. For one example, see http://www.ucos-ii.com/ (uC/OS was originally available as freeware, uC/OS-II is $50). There is also no reason you can't "roll yer own" : use DOS (or equivalent) to load your program image into memory, then grab all the interrupts and the machine is yours. You can even use (to some extent) a DOS-based debugger like Codeview (although obviously not in real time). Of course, response time remains a problem to be solved, just like with any uC. You'll definitely need some specialized hardware ... Randall - ---------------------------------------------------------------------------- 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: Tue, 28 Mar 2000 12:26:26 -0500 From: Will McGonegal Subject: Re: O2 sensor response times- catalyst Further to my earlier post and after further investigating O2 sensor info with my colleague Jim (Heywood book, and Bosch Electric\Electronic Handbook), it is evident that non-wide ratio O2 sensors (regular on/off rich/lean sensors) also have a thin gas-permeable platinum layer. This acts as a catalyst. My understanding is that this is used on regular sensors to help completely combust all the O2 left in the exhaust with a rich mixture. (The Bosch book states that even with a lambda of 0.95 (rich) there can be 0.2-0.3% O2 by volume). I'm assuming that this extra O2 must react with some fuel (if there is excess fuel) to prevent it from misreading that the AFR is actually lean (since it would detect this small amount of O2 that didn't get combusted by the engine). Similar catalyst action is used in the wide ratio sensors as in my previous post. Any thoughts from those who know? Another interesting thing I read was that excessive temperature shortens the service life. Sustained temperature can be 850 C, 930 C for short periods. Aside from lead and other fuel contamination, could this be why the wide ratio sensors don't have that long a service life? If they are operating in a AFR rich environment, then the catalytic action (reacting unburned fuel) is going to generate a lot of heat. Maybe this causes the sensors to have a shorter life when operating in a rich environment. And this may partially explain why in the Honda lean burn car the wide ratio sensor would last a long time (it runs lean, no extra fuel to react on the sensor, therefore the sensor runs cooler). If this is the case, perhaps some system could be devises to measure the sensor temperature (heater resistance perhaps) and if the sensor starts to get too warm, get it cooled somehow. In 2-strokes unburned AFR mixture gets into the exhaust through the scavenging process. I thought this is why O2 sensors could not be used in 2-strokes (lots of un-combusted O2 in exhaust even with rich mixtures). With a catalytic reaction occurring at the sensor (wide ratio or regular) I'm curious as to why they are not recommended for 2-stroke use. Maybe it's because they get too hot and don't last long? Any thoughts on O2 sensor heating? Just for anyone interested, in the NTK wide ratio sensor manual it states that the O2 "pump" current varies from -12.5 to 12.5 mA, the O2 sensor is biased with a 25 uA +/- 3 uA current (the sensor output voltage (450 mV for stoich) is read on top of that). The heater voltage is 10.5 +/- 0.5 volts. I still don't know how you go from pump current to AFR! > > ------------------------------ > > > > >Heywood pg 301: "Equilibrium is established in the exhaust gases > > >by the catalytic activity of the platinum metal electrodes." - ---------------------------------------------------------------------------- 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: Tue, 28 Mar 2000 11:39:28 -0600 From: Gary Peyton Subject: Re: Re 8051 EFI At 08:11 AM 03/28/2000 -0800, you wrote: [snip] >I'm thinking of doing a six cylinder version for my Jeep Cherokee since the 1987 Jeep was >the first one with the inline Six and Fuel Injection and it lets me try a Six Cylinder >engine in preparation for six cylinder Lycoming Aircraft Engines. For the six cylinder >I'll switch over to a C167C processor which means a new compiler etc. If the client >doesn't fund this I may just do the design myself (and therefore own the board design) and >make the board available to the DIY-EFI group. > >Cheers, >John Dammeyer All right! (see signature) If your client is (or you might be) thinking of marketing something like this to Jeep owners, I can tell you (what you probably already know) that there is a large market for aftermarket [:)] performance mods like this for Jeeps, especially if you can get down out of the Haltech/SDS/etc price range by coming up with a relatively simple product. Same is true for Datsun Z-car owners. Drivers of both marques (and probably a lot of others) tend to not have a lot of money, but will spend a lot of what they have on their vehicles and would really go for a moderately-priced engine management system that is better than the stock unit. I know that's not the point of this list, but had to say it anyway, being one or two of those folks. ================================================================= GarP aka Gary Peyton '89 Cherokee 4.0L I6, AT, Command-Trac (231), tow hooks [Daily Driver] '81 Datsun 280ZX FI 2.8L L6, 5-speed [Sunny-day Driver] '95 Saturn wagon dohc [Wifely driver :] ================================================================= - ---------------------------------------------------------------------------- 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: Tue, 28 Mar 2000 13:42:04 -0800 From: "Fritz Moore" Subject: RE: O2 sensor response times A fairly basic question here, Can the wide range 02 sensor measure AFR on the rich side of stoichiometric? If so is this because it adds 02 to the sample and then measures the 02 current required to get back to a lean i.e. 02 present condition? I guess my real question is how can it measure AFR by 02 content if there is no 02 content in rich conditions? Thank you, Fritz - -----Original Message----- From: owner-diy_efi@xxx.org]On Behalf Of Garfield Willis Sent: Monday, March 27, 2000 3:36 PM To: diy_efi@xxx.org Subject: Re: O2 sensor response times On Mon, 27 Mar 2000 16:29:44 -0600, Gary Peyton wrote: >I had read somewhere that the response time of the platinized zirconia >sensors was 2-3 seconds, and that was one reason why they werent very good >for close engine management during acceleration (along with the way the >L-jetronic system used that information). Ahh, this allows me to clear up a possible mistake I made a few posts ago when Mike "tah" M. asked about a "platinum O2 sensor". AFAIK, the platinum is just used to provide the metallic connection between the ZrO2 material and wiring to the sensor. It's probly vacuum-deposited onto the outsides of the layers of ZrO2 that make up a sensor, giving a metallic area that can be wired to. Don't quote me, I'm not a physical chemist; there might indeed be other electro-chemical reasons as well why platinum is the material of choice, but it appears from diagrams on how most all ZrO2 sensors are built, that the platinum IS the metallic/electrical connection to the ZrO2 substrate. In the real world, you're likely to see anything from 2Hz to 0.5Hz stoich-crossing frequency. 3 seconds is getting on the slow side. >Maybe I'm suffering under a misconception here, since the www.tech2tech.net >discussion says that "A good O2 sensor will usually module several cycles >per second.". Are they referring to a simple one-wire zirconia sensor? Yeah, sorta. What's in view there is the overall cycle-time of the control loop in closed-loop mode. From the time the controller sees the measured mixture is lean of stoich, till it increases the injector pulse-widths, till the time the mixture passes from lean thru stoich to rich of stoich, and the sensor now says "we're rich", and the cycle starts over again. Ordinary switch-type O2 sensors/controllers all work this way, be they one, two, or heated 4-wire (there are some wideband 4-wire sensors, but I'm of course leaving them out of the switch-type category). Obviously one of the parameters in the phase-lag of this feedback loop is how far from the combustion chamber in *time*, the O2 sensor actually sits. Transport delay of the gases to the sensor, has to be added to the sensor and controller delays. Also, one of the key aging/contamination phenom of all these sensors is that they become sluggish in their response to changes in exh gas. This will slow down cycle-time of the controller also, of course, because it will take longer for the sensor to SEE the mixture change that the injectors are providing, the slower the sensor is to respond. He's just giving a ruleOthumb for these stoich-crossing type controllers. BUT even in controllers based on wideband sensors, which ARE capable of holding the mixture right at stoich (or any other commanded AFR) without any significant excursions lean or rich, AFR swings MAY be programmed into the controller *anyway*, to provide the cat with needed lean & rich periods, depending on what type of cat is used in the design of the exh system. This is explained on pg. 656-657 of Heywood's "Internal Combustion Engine Fundamentals". [BTW, especially if you're a science type as your signature suggests, you should have this book or something like it that's as good. There is a wealth of both real-world practical insights AND good in-depth understanding on many DIY topics in Heywood's book.] >If a sensor like the LAF O2-pump >type sensor employs 2 of these, how can its reponse time be any better? Well, the description of the pump-type sensors as "being made of 2 ordinary switch-type sensors" is no doubt an "operational analogy" for the sake of explanation, not necessarily a statement of actual fact of physical construction and performance/behavior, per se. My refuge as a person who hasn't a clue about stuff such as "solid electrolytic nernst reactions" or "gas ion diffusion constants in porous ceramics", is to say, "well, they just are faster". Heh. There's your daily dose of/on exhaust gas. 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 - ---------------------------------------------------------------------------- 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: Tue, 28 Mar 2000 15:42:54 -0800 From: garwillis@xxx.com (Garfield Willis) Subject: Re: O2 sensor response times On Tue, 28 Mar 2000 13:42:04 -0800, "Fritz Moore" wrote: > Can the wide range 02 sensor measure AFR on the rich side of >stoichiometric? > > If so is this because it adds 02 to the sample and then measures the 02 >current required to get back to a lean i.e. 02 present condition? > > I guess my real question is how can it measure AFR by 02 content if there >is no 02 content in rich conditions? Yes, right there is *depletion* of O2 under rich conditions; hence, the O2 pump in these sensors must *supply* O2 ions to bring the sample chamber back to stoich (neither excess nor depletion). It's supplying O2 ions to balance the stoichiometry of primarily H & CO, and some unburnt HCs, when rich. When lean of stoich, the current pump is simply removing excess O2 from the sample chamber. So yeah, it's never really "measuring" O2 per se, but *balancing* O2 in the diffusion chamber, removing excess if lean, and providing what's needed to make up for a depletion of O2, if rich. The amount needed to balance IS a measure of either the amount of O2 in excess or the O2 that's missing, sotaspeak. From this, the AFR is computed. HTH, 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: Tue, 28 Mar 2000 17:03:56 PST From: "Bill the arcstarter" Subject: Re: aftermarket ecu etc... "Toby Atwater" wrote: >Does anybody know of a aftermarket ECU that has some kind of PC output? All >the ones I have seen either have a separate unit with a small b/w lcd >screen, or else they have some kind of data logging Holley 4Di systems. Fuel map, MAP sensor, TPS, RPM, engine air and water temp, lots of other stuff all tweakable and loggable via a PC. - -Bill ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.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: Wed, 29 Mar 100 10:22:49 +0800 (WST) From: Bernd Felsche Subject: Re: O2 sensor response times- catalyst Will McGonegal writes: >Just for anyone interested, in the NTK wide ratio sensor manual it >states that the O2 "pump" current varies from -12.5 to 12.5 mA, the O2 >sensor is biased with a 25 uA +/- 3 uA current (the sensor output >voltage (450 mV for stoich) is read on top of that). The heater >voltage is 10.5 +/- 0.5 volts. I still don't know how you go from >pump current to AFR! This is derived from the new Bosch SI Engine Management book: The -25 mA would correspond to approx lambda of 0.7, +25 mA to approx 2.2. 0 mA is lambda = 1. You should be able to fit a curve through those three points. Not that it's not often useful to have a lambda of 0.7 - that's way more rich than any steady-state running would require. - -- Real Name: Bernd Felsche Email: nospam.bernie@xxx.au http://www.perth.dialix.com.au/~bernie - Private HP - ---------------------------------------------------------------------------- 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: Wed, 29 Mar 100 10:34:40 +0800 (WST) From: Bernd Felsche Subject: Re: O2 sensor response times Fritz Moore writes: >A fairly basic question here, >Can the wide range 02 sensor measure AFR on the rich side of >stoichiometric? >If so is this because it adds 02 to the sample and then measures >the 02 current required to get back to a lean i.e. 02 present >condition? >I guess my real question is how can it measure AFR by 02 content if >there is no 02 content in rich conditions? By pumping a little from the "outside". The wide-band O2 sensor needs outside air as a reference, just like the "switching type" - -- Real Name: Bernd Felsche Email: nospam.bernie@xxx.au http://www.perth.dialix.com.au/~bernie - Private HP - ---------------------------------------------------------------------------- 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: Tue, 28 Mar 2000 20:32:53 -0600 From: "Dan Plaskett" Subject: Diacom cable Hey gang, Has anyone built a Diacom cable? I'd like to build one that is about 20ft long so I can use the PC in my garage (not a portable). I thought I saw a schematic some time ago but since the archives have been down haven't been able to find it. 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: Tue, 28 Mar 2000 20:53:55 -0600 From: "Brian Franchuk" Subject: Looking for pulse output MAF Hi, I'm looking for a GM MAF (pulse output) that can handle the flow from a 4.0 liter motor (approx 220hp). I've already built the pulse to AFM conversion box so I need to use a pulsed sensor. The sensor I've got now (I got it from the U-pull-R yard out of a 2.8l chevy) can't handle the flow rate. Any help is appreciated. Brian - ---------------------------------------------------------------------------- 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: Wed, 29 Mar 100 11:17:14 +0800 (WST) From: Bernd Felsche Subject: Re: Cheap Protection ... The circuit Thanks for all the hints and comments on the means of protecting inputs. The first draft of the circuit schematic can be found at http://www.perth.dialix.com.au/~bernie/tech/LW.pdf I've done a few trial layouts and the components "fit" easily on a 50mm-square single-sided PCB with only two air-wires. It's not yet a working design; still need to check on how to drive some sort of audible warning (at the moment I'm using a "spare" buffer on to 4050), to confirm the driving of the FET (which will be PWM), and to finalise values for the input filter caps and resistors. - -- Real Name: Bernd Felsche Email: nospam.bernie@xxx.au http://www.perth.dialix.com.au/~bernie - Private HP - ---------------------------------------------------------------------------- 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: Tue, 28 Mar 2000 21:49:01 -0600 From: MysticZ Subject: Re: Diacom cable Dan Plaskett wrote: > > Hey gang, > > Has anyone built a Diacom cable? I'd like to build one that is about 20ft > long so I can use the PC in my garage (not a portable). I thought I saw a > schematic some time ago but since the archives have been down haven't been > able to find it. I have it if you need it. Just e-mail me. Haven't gotten around to building it yet, but I plan to in a couple of days when I have a little spare time. - -- Steve 97 Chevy Camaro Z28, Mystic teal, A4, not stock 90 Kawasaki EX500A4, black, M6, not even CLOSE to stock! lt1_z28@xxx.net/~lt1_z28 Aluminum, steel, carbon fiber, titanium, and two cast iron balls. McMillan Motorsports- http://www.mmsbikes.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: Tue, 28 Mar 2000 20:01:31 -0800 From: garwillis@xxx.com (Garfield Willis) Subject: Re: O2 sensor response times- catalyst On Wed, 29 Mar 100 10:22:49 +0800 (WST), Bernd Felsche wrote: >Will McGonegal writes: > >>Just for anyone interested, in the NTK wide ratio sensor manual it >>states that the O2 "pump" current varies from -12.5 to 12.5 mA, the O2 >>sensor is biased with a 25 uA +/- 3 uA current (the sensor output >>voltage (450 mV for stoich) is read on top of that). The heater >>voltage is 10.5 +/- 0.5 volts. I still don't know how you go from >>pump current to AFR! > >This is derived from the new Bosch SI Engine Management book: > >The -25 mA would correspond to approx lambda of 0.7, +25 mA to >approx 2.2. 0 mA is lambda = 1. > >You should be able to fit a curve through those three points. > >Not that it's not often useful to have a lambda of 0.7 - that's way >more rich than any steady-state running would require. Argh. All I'm at liberty to say to the immediately above is "BZZZT". Remember I warned ya, these devices are both spendy and VERY easy to destroy by over-pumping or mis-pumping (pumping in the wrong direction). It's referred to in the trade as "blackening" the sensor. Others who have worked with these sensors in industry and have no commercial interest in them as I do, will also confirm this. I shit you not. Besides, I'm surprised that a Bosch book would even mention an NTK sensor, but those numbers aren't even close. BTW, 0.7 lambda is roughly 10AFR. WOT turbo engines can/will fuel in the 10'sAFR during transient enrichment under heavy load, so altho this isn't "steady-state running", being able to see and measure these rich excursions isn't so far afield. And carb'd engines will lean-misfire and even backfire, if idle-jetting combined with a rapid undamped throttle-off runs the AFR to above 17-18, so measuring to this lean, again altho not "steady-state" still can be important, too. I won't be saying too much more about tech stuff concerning these sensors; as an instrument vendor I'm just not able to participate the way I'd like to, without raising suspicions of bias. C'est le vie. Just caveat your emptors, doods, and save at least one good, pristine, virgin, unmangled sensor for EGOR, will ya? TTFN, 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: Tue, 28 Mar 2000 19:06:20 +0100 From: Ade + Lamb Chop Subject: Re: DIY-EFI's Funny 'reply all' At 10:30 28/03/00 -0600, steve ravet wrote: >> More to the point - Who is Hektor Valesh? > >Jon Valesh hosts our new WWW server. Hektor is the machine that runs >the list. I've never seen a computer with a first and last name >before... > >> >> Ade + Lamb Chop wrote: >> >> > Why is it that with DIY-EFI when I click my 'reply to all' button in my >> > mailer I reply to diy-efi twice rather than the original sender and >> > diy-efi? I am a member of another this and that is fine... Why is it >> > different for diy-efi? > >Doesn't do that for me, maybe it's something with your mail client. Try >using regular reply instead of reply all. Problem is that I just do reply all automatically. I am a member of the Mini-list which has about 75-150 mails per day!! Ade - ---------------------------------------------------------------------------- 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: Tue, 28 Mar 2000 19:08:26 +0100 From: Ade + Lamb Chop Subject: Re: DIY-EFI's Funny 'reply all' At 09:01 28/03/00 -0800, Jon V. wrote: >On Tue, 28 Mar 2000, Peter Gargano wrote: > >> More to the point - Who is Hektor Valesh? > >Hey! Don't you know Hektor V.? Or was this one of those "who is Kaiser >Soze?" type questions? > >Ade + Lamb Chop wrote: > >> Why is it that with DIY-EFI when I click my 'reply to all' button in my >> mailer I reply to diy-efi twice rather than the original sender and >> diy-efi? I am a member of another this and that is fine... Why is it >> different for diy-efi? > >Doesn't do that for me... what mailer are you using? Eudora Pro (uck) have got a choice on this ATM as it has to run directly off the server I don't know of another one that does. Ade - ---------------------------------------------------------------------------- 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: Tue, 28 Mar 2000 19:08:26 +0100 From: Ade + Lamb Chop Subject: Re: DIY-EFI's Funny 'reply all' At 09:01 28/03/00 -0800, Jon V. wrote: >On Tue, 28 Mar 2000, Peter Gargano wrote: > >> More to the point - Who is Hektor Valesh? > >Hey! Don't you know Hektor V.? Or was this one of those "who is Kaiser >Soze?" type questions? > >Ade + Lamb Chop wrote: > >> Why is it that with DIY-EFI when I click my 'reply to all' button in my >> mailer I reply to diy-efi twice rather than the original sender and >> diy-efi? I am a member of another this and that is fine... Why is it >> different for diy-efi? > >Doesn't do that for me... what mailer are you using? Eudora Pro (uck) have got a choice on this ATM as it has to run directly off the server I don't know of another one that does. Ade - ---------------------------------------------------------------------------- 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 #127 ***************************** 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".