DIY_EFI Digest Sunday, May 16 1999 Volume 04 : Number 286 In this issue: Injector Firing Voltage Re: In cylinder pressure measurement Re: Injector Firing Voltage Re: horse power/acceleration Re: BMFC, Tiiming, and Coatings Re: Yet another O2 sensor fakeout trick Re: FYI - Patent 5704321 - Traveling spark ignition system Re: SAAB DI coils - was Re: "ION" information ... Re: O2 voltz Re: O2 voltz Re: O2 voltz Re: O2 voltz Re: O2 voltz Re: BMFC, Tiiming, and Coatings Re: Variable Restrictiveness Exhaust Re: O2 sensor fakeouts Re: O2 voltz switching eprom Re: O2 voltz Re: I'm BACK...but NOW as a VENDOR Re: BMFC, Tiiming, and Coatings Re: BMFC, Tiiming, and Coatings Re: In cylinder pressure measurement Re: BMFC, Tiiming, and Coatings Re: O2 voltz Re: SAAB DI coils - was Re: "ION" information ... Re: O2 voltz See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Sat, 15 May 1999 16:12:57 -0400 From: "Bruce Plecan" Subject: Injector Firing Voltage I hooked the scope up to a GM ecm running 8 saturated injectors. The normal 12v only appreared rarely. The usual voltage of the injectors firing was 75-100v.. So this flyback/kickback, is a very large issue. This would seem to imply to me, that the stock ecm doesn't clip the voltage by reverse biasing a diode, to contol it, but rather use a scheme, where they deal with it. Maybe clipping these signals has a adverse affect on the injectors opening/closing.. Jus curious, if this makes sense. Grumpy ------------------------------ Date: Sat, 15 May 1999 14:08:28 -0700 (PDT) From: Mark Wilcutts Subject: Re: In cylinder pressure measurement This has been done in a labratory environment for at least 50 years. The main manufacturers are Kistler (www.kistler.com) and AVL List (www.avl.co.at). For mounting, either a modified spark plug or cylinder head flush mounting. The sensors are $500-$1500 and require a charge amplifier ($1000). They suffer from drift and thermal shock but are otherwise excellent for combustion analysis. Gross things like misfire and knock are easily noticeable. Recently, in our lab we have been using an optical transducer (www.optrand.com) that measures the deflection of a flush-mounted diphragm remotely with a tiny laser through an optical fiber. These currently cost about $900 and don't need a charge amp. Future indications are that the sensor electronics can be miniturized and the sensor produced at very low cost. One problem is, how to collect all that cylinder pressure data and then what to do with it once you have it? We use a DSP data acquisition card ($$$) clocked by a crankshaft mounted optical encoder at 1 CAD increments. We are using the data to back out actual rate of burning and thus get some measure of the quality of combustion, our emphasis being on combustion during cold start. - -- Mark Wilcutts Mechanical Engineering Department University of California On Wed, 12 May 1999, C. Brooks wrote: > Has anyone ever heard of anybody doing this? I was talking with someone > about data acquisition systems and the subject came up while we were > discussing methods of knock detection. I'm not to enthusiastic about being > able to monitor A/F ratios accurately or in realtime, and our conversation > kinda stuck with me. > > If anyone's ever seen or heard about somebody performing in cylinder > pressure measurements I'd love to hear about it. I imagine the transducers > would have to be pretty tough, how would they mount? What kind of sample > rate do you think would be needed? Best of all, who would make a sensor that > could take the abuse??? > > > > Charles Brooks ------------------------------ Date: Sat, 15 May 1999 14:12:02 -0700 (PDT) From: Mark Wilcutts Subject: Re: Injector Firing Voltage The injector driver chips used in ECMs are designed to be immune to flyback. You should see 12V on the line most of the time, then a short ground pulse of duration equal to the dwell time, then the large spike from flyback... - -- MW On Sat, 15 May 1999, Bruce Plecan wrote: > I hooked the scope up to a GM ecm running 8 saturated injectors. The normal > 12v only appreared rarely. The usual voltage of the injectors firing was > 75-100v.. > So this flyback/kickback, is a very large issue. > This would seem to imply to me, that the stock ecm doesn't clip the voltage > by reverse biasing a diode, to contol it, but rather use a scheme, where > they deal with it. Maybe clipping these signals has a adverse affect on the > injectors opening/closing.. > Jus curious, if this makes sense. > Grumpy > ------------------------------ Date: Sat, 15 May 1999 17:02:48 -0500 From: Tom Sharpe Subject: Re: horse power/acceleration Good stuff, I just wanted a relative number - crankshaft acceleration at x rpm, y load for comparison/tuning. If we change the mixture at point x-y what does the crank acceleration (power?) do?????? just more food for thought... TomS Ord Millar wrote: > Take the acceleration at some point in your curve, call it A, and multiply > by vehicle mass. This gives the linear force exerted by the rear wheels. > (front wheels?). F=MA (it is convinient to measure acceleration here in G, > and mass in lbs). > > Torque at the rear wheel is F / (D*2*PI), where D is wheel diameter. Engine > torque is rear torque / axle ration / transmission ratio + driveline loss. > (keep D in ft for simplicity, loss in ft-lbs) > > Engine HP is engine TQ * engine RPM / 5251. (when TQ is in lbs-ft) > > So: HP = (MA/(D*2*PI)/ratio+loss) * RPM / 5251. > > Add in air & rolling resistance, and you're almost there! > -----Original Message----- > From: Jeff W > To: diy_efi@xxx.edu> > Date: Thursday, May 13, 1999 7:35 PM > Subject: horse power/acceleration > > >dear sir > >I am writing to you because I am looking for the correct > calculation/formula > >for finding the approximate horse power conversion from vehicle weight and > >acceleration curve. > > I am presently in Vancouver community college, in Vancouver B.C and my > >instructor (Dave William's) gave me your e-mail address feeling that you > may > >be of some help to me. > > > >vehicle weight + acceleration curve + some other things I don't know= > >approximate HP@xxx. > >thank you! > >Jeff Weinberger > >sierraj@xxx.com > > > > > > ------------------------------ Date: Sat, 15 May 1999 17:53:18 -0500 From: Tom Sharpe Subject: Re: BMFC, Tiiming, and Coatings Just seat of the pants measurements... medium hot 406 sbc, electric fan (on @ 200), griffin radiator, 7 qt pan, with mild overheating problems... Idle in traffic H2O @xxx. At 75 mph cruse, lite load, H2O was 190-195, now 180, (thermostat), oil was 200-210 now 185. Around Elkart lake for 1 hr, H2O @210, oil at 200, was 190, 190 before we were back to the pits. tom S HPC has oil sheading coatings for crank, rods, block etc.. Tom S Bruce Plecan wrote: > Has anyone run any "independent" testing on these barrier coatings for what > they actually have seen as an improvement pre+post coating?. > Has any one run any endurance tests?. > Do I need mention that this might need a complete recal to get right. > Bruce ------------------------------ Date: Sat, 15 May 1999 19:06:57 -0400 From: Shannen Durphey Subject: Re: Yet another O2 sensor fakeout trick James Seabolt wrote: > > Thinking about trying yet another trick. I just can't leave this one thing > alone. I would really like to get rid of my 5th injector. The fuel line is > touching several items on the motor and I am afraid it might chap and > spring a leak. Also it doesn't look very professional anyway. And the fact > I am sure the injectors will provide enough fuel if I could just boost the > pulse rate up a bit. > Ummmm.. Did you say in a previous post that the computer definitely relies on O2 reading when it's at Wide Open Throttle? Shannen ------------------------------ Date: Sun, 16 May 1999 09:27:11 +1000 From: Peter Gargano Subject: Re: FYI - Patent 5704321 - Traveling spark ignition system Well, I use the term losely. I just started looking at the references that patents refer to (both backwards and forwards) and also the SAE papers. That's all! Just look at the following patent's description and you'll see what I mean. http://www.patents.ibm.com/details?pn=US05704321__ Stowe, Ted-SEA wrote: > > how do you search the patent archives ? - -- Peter Gargano peter@xxx.au http://www.techedge.com.au/teinfo.htm Ph: +61 2 6251 5519 Fax: +61 2 6251 6646 ------------------------------ Date: Sun, 16 May 1999 09:52:04 +1000 From: Peter Gargano Subject: Re: SAAB DI coils - was Re: "ION" information ... Well, 4862093 is a conceptial diagram, and certainly good enough to describe what's happening, but the difference between a conceptial circuit and an actual schematic with transistor type numbers etc... I was wondering if anyone has had a look at a real SAAB ION-sense module and come up with a real schematic. I ask this because I read in the archives that there were a few of these SAAB modules floating around (some time ago) and someone was going to check it out (but I could find no reference of this actually happening). Jim Crance's email made me wonder if the modules he has are the ION-sense versions. I also understand that the later SAAB ION-sense modules are potted and impossible to actually get into. Anyway, I don't really want a SAAB module, but a real life schematic of an ION-sense circuit so I can start playing with it on my 68HC11 ignition controller. PG. Bruce Plecan wrote: > > The patent 4862093 has a schematic will it > Grumpy > > > So, is this the same DI system with the ION sense circuitry? > > If so, has anyone published the actual schematic for one of > > these units? > > > > JCsDOOR@xxx.com wrote: > > > > > If you pull the cover off a Saab di you will find 4 coils that > > > unplug and can be used for other apps. > > > Jim crance > > > Ps I still have my cone hat > > > > -- > > Peter Gargano peter@xxx.au > > Ph: +61 2 6251 5519 Fax: +61 2 6251 6646 > > - -- Peter Gargano peter@xxx.au http://www.techedge.com.au/teinfo.htm Ph: +61 2 6251 5519 Fax: +61 2 6251 6646 ------------------------------ Date: Sat, 15 May 1999 19:55:54 -0400 From: Shannen Durphey Subject: Re: O2 voltz Bruce Plecan wrote: > > For the lack of anything else to do, I hooked the heated O2 up, and was > looking at the voltage drop across a sensor resistor, I been thinking of > using. > As the heater warmed up, the voltage drop across the resistor changed, > just meaning the heater was drawing less current. > I had hooked the scope probe across the O2, and cold there was no output, > to be expected, but as it warmed up the output swung toward, .2v. Just in > atmospheric conditions. Ok, so then it should go way high in pure O2 right, > nope went a little over .3, and stopped there. > Did I need to load the sensor?. > The heater doesn't go to a high enough temperature for the O2 to fully > swing high?. > Does the engine side need to see a slight amount of pressure to reference > to?. > Grumpy I thought sensor voltage increased as O2 content on element side of sensor decreased. I suspect if the O2 concentration on the Ref side of the sensor was increased the voltage would rise some. Not everyone can duplicate the O2 portions of your experiments at home. ; ) Shannen ------------------------------ Date: Sat, 15 May 1999 19:59:02 -0400 From: Shannen Durphey Subject: Re: O2 voltz David A. Cooley wrote: > > At 04:02 PM 5/15/99 -0400, you wrote: > >For the lack of anything else to do, I hooked the heated O2 up, and was > >looking at the voltage drop across a sensor resistor, I been thinking of > >using. > > As the heater warmed up, the voltage drop across the resistor changed, > >just meaning the heater was drawing less current. > > I had hooked the scope probe across the O2, and cold there was no output, > >to be expected, but as it warmed up the output swung toward, .2v. Just in > >atmospheric conditions. Ok, so then it should go way high in pure O2 right, > >nope went a little over .3, and stopped there. > > Did I need to load the sensor?. > > The heater doesn't go to a high enough temperature for the O2 to fully > >swing high?. > > Does the engine side need to see a slight amount of pressure to reference > >to?. > > Bad thing about O2 sensors is they aren't truly O2 sensors... they are HC > sensors. > In pure O2, the sensor should keep a low voltage. In an environment rich > with HC (IE propane, unburnt fuel etc) they should go .9-1 Volt. Ok, please splain this statement. O2 sensor voltage drops when spark plugs fail to fire, and there's more HC present than when everything's sparking normally. Why the contradiction? Shannen ------------------------------ Date: Sat, 15 May 1999 20:39:19 -0500 From: Steve Gorkowski Subject: Re: O2 voltz Hi Bruce Are you using the computer scope probe ? With a one wire o2 sensor or Ngk i can read full one volt with no loading with same probe. How are you heating it. Steve Shannen Durphey wrote: > Bruce Plecan wrote: > > > > For the lack of anything else to do, I hooked the heated O2 up, and was > > looking at the voltage drop across a sensor resistor, I been thinking of > > using. > > As the heater warmed up, the voltage drop across the resistor changed, > > just meaning the heater was drawing less current. > > I had hooked the scope probe across the O2, and cold there was no output, > > to be expected, but as it warmed up the output swung toward, .2v. Just in > > atmospheric conditions. Ok, so then it should go way high in pure O2 right, > > nope went a little over .3, and stopped there. > > Did I need to load the sensor?. > > The heater doesn't go to a high enough temperature for the O2 to fully > > swing high?. > > Does the engine side need to see a slight amount of pressure to reference > > to?. > > Grumpy > I thought sensor voltage increased as O2 content on element side of > sensor decreased. I suspect if the O2 concentration on the Ref side > of the sensor was increased the voltage would rise some. > > Not everyone can duplicate the O2 portions of your experiments at > home. ; ) > Shannen ------------------------------ Date: Sat, 15 May 1999 19:11:45 PDT From: "Bill the arcstarter" Subject: Re: O2 voltz Various people wrote: >> I had hooked the scope probe across the O2, and cold there was no >>output, >>to be expected, but as it warmed up the output swung toward, .2v. Just in >>atmospheric conditions. Ok, so then it should go way high in pure O2 >>right, >>nope went a little over .3, and stopped there. >> Did I need to load the sensor?. >> The heater doesn't go to a high enough temperature for the O2 to fully >>swing high?. >> Does the engine side need to see a slight amount of pressure to >>reference >>to?. > >Bad thing about O2 sensors is they aren't truly O2 sensors... they are HC >sensors. In pure O2, the sensor should keep a low voltage. In an >environment rich with HC (IE propane, unburnt fuel etc) they should go .9-1 >Volt. I can confirm this. My "O2" sensor could NOT distinguish between air and 100% argon (from a TIG welder). However it responded gloriously to a bit of raw propane from the plumber's torch... (The O2 sensor was a 3-wire electrically heated Bosch unit) There is indeed a great mystery here as there is obviously much more to the story than "They sense O2". ('cause they don't!) If anyone knows the whole story I'd love to hear it :) - -Bill _______________________________________________________________ Get Free Email and Do More On The Web. Visit http://www.msn.com ------------------------------ Date: Sat, 15 May 1999 22:17:55 -0400 From: "David A. Cooley" Subject: Re: O2 voltz At 07:59 PM 5/15/99 -0400, you wrote: >Ok, please splain this statement. O2 sensor voltage drops when spark >plugs fail to fire, and there's more HC present than when everything's >sparking normally. Why the contradiction? My example was under conditions where combustion was actually happening. Voltage will drop with increasing O2, but under combustion conditions, the exhaust actually starts having more CO and HC as it get's richer and less O2. =========================================================== David Cooley N5XMT Internet: N5XMT@xxx.net Packet: N5XMT@xxx. Member #7068 Sponges grow in the ocean... Wonder how deep it would be if they didn't?! =========================================================== ------------------------------ Date: Sat, 15 May 1999 19:24:47 -0700 (PDT) From: Jim Davies Subject: Re: BMFC, Tiiming, and Coatings On Sat, 15 May 1999, Greg Hermann wrote: > POR-15 is also recommended by the mfgr for the inside of blocks. Painting > them is wise--condensation does happen in there! > I once had access to a well equipped test lab and they would routinely do engine oil analysis for me. What was interesting [to me] was that although the engine in question was several years old at the time, the silicon leached out from casting was pretty high... ------------------------------ Date: Sat, 15 May 1999 22:30:04 -0400 From: "Ord Millar" Subject: Re: Variable Restrictiveness Exhaust - -----Original Message----- From: GARY To: diy_efi@xxx.edu> Date: Saturday, May 15, 1999 1:13 PM Subject: Re: Variable Restrictiveness Exhaust >3) >I am trying to decide the best way to dampen the signal from my Knock >Sensor (the Subaru). The resistance of the KS is 520K ohm. The ECU >appears to be sending about two to three volts D.C. to the Knock Sensor, >but I don't know if that remains constant throughout operation. > >What do you guys think of a first resistor in series to dampen output >along with a second resistor paralleling the seriesed KS and first >resistor to make the overall resistance/impedance 520K ohm? or using a >diode to allow the D.C. monitor current to pass while offering >resistance to the KS generated signal. I thing a diode would filter the >KS A.C. signal into D.C. and cause a problem. Any other ideas? First of all, isn't the KS a piezo sensor? If so, I think DC resistance doen't really matter. If you want to attenuate, you could build a divider around it - two resistors in series accross the element, leave one wire connected to the KS, connect the other to the junction of the resistors. If it is really damping that you want, instead of just attenuation, then you need to build a low pass filter. ------------------------------ Date: Sat, 15 May 1999 21:39:51 -0500 (CDT) From: Roger Heflin Subject: Re: O2 sensor fakeouts On Sat, 15 May 1999, Frederic Breitwieser wrote: > Greetings, > > I haven't been keeping up with many of these threads, but I noticed that > the O2 fakeout diagrams I've seen posted here still had the O2 sensor... > are the purpose of the diagrams to "adjust" the output of the O2 sensor > on a live vehicle? Or, are they for testing an ECM on a bench? Because > if its the latter, you don't need the sensor obviously, and a 5 or 10 > turn 100K pot and a D battery would do the trick nicely. > > D cell + ----> --\ > / 100k 5 or 10 turn pot > \ > / <------- to o2 sensor wire on ECM > \ > / > D cell - --0--> --\ > | > | > ground > > > > Or, have I once again missed the point? > I believe the O2 fake sensors are used on ODBII vehicles that have two pairs of O2 sensors. The circuit may be the circuit to make the one after the CAT look right when the CAT is missing or bad. Roger ------------------------------ Date: Sat, 15 May 1999 22:55:39 -0400 From: "Bruce Plecan" Subject: Re: O2 voltz - ----- Original Message ----- From: Steve Gorkowski To: Sent: Saturday, May 15, 1999 9:39 PM Subject: Re: O2 voltz > Hi Bruce > Are you using the computer scope probe ? Yes > With a one wire o2 sensor or Ngk i can > read full one volt with no loading with same probe. How are you heating it. No, I'm using a 4 wire GM divourced ground O2 sensor. 12v 1.8 ohm sensor resistor Bruce > > Steve > > Shannen Durphey wrote: > > > Bruce Plecan wrote: > > > > > > For the lack of anything else to do, I hooked the heated O2 up, and was > > > looking at the voltage drop across a sensor resistor, I been thinking of > > > using. > > > As the heater warmed up, the voltage drop across the resistor changed, > > > just meaning the heater was drawing less current. > > > I had hooked the scope probe across the O2, and cold there was no output, > > > to be expected, but as it warmed up the output swung toward, .2v. Just in > > > atmospheric conditions. Ok, so then it should go way high in pure O2 right, > > > nope went a little over .3, and stopped there. > > > Did I need to load the sensor?. > > > The heater doesn't go to a high enough temperature for the O2 to fully > > > swing high?. > > > Does the engine side need to see a slight amount of pressure to reference > > > to?. > > > Grumpy > > I thought sensor voltage increased as O2 content on element side of > > sensor decreased. I suspect if the O2 concentration on the Ref side > > of the sensor was increased the voltage would rise some. > > > > Not everyone can duplicate the O2 portions of your experiments at > > home. ; ) > > Shannen > > > ------------------------------ Date: Sat, 15 May 1999 19:58:06 -0700 From: "Ron Jeremy" Subject: switching eprom I am a student and for a class project I am researching the best way to make a switchable Eprom for a GM P-4 computer, the normal Eprom is a 27c128, I would like to have 8 or 10 different programs loaded for testing in back to back conditions. If you could let me know the best way to do such a thing it would be appreciated. I did search the archive, but thought the information may have changed since the 97 postings I found. Thanks, Ron Get your FREE Email at http://mailcity.lycos.com Get your PERSONALIZED START PAGE at http://my.lycos.com ------------------------------ Date: Sat, 15 May 1999 23:03:28 -0400 From: "Bruce Plecan" Subject: Re: O2 voltz Heat is what drives the reaction. No heat, no reaction, no voltage. BUT, a poorly lite, reaction, that causes, a miss, can generate a high O2 reading. Bruce Staff been to market 3x today looking for cereal cables, we're committed to finding them thou..(well maybe commitable) > Ok, please splain this statement. O2 sensor voltage drops when spark > plugs fail to fire, and there's more HC present than when everything's > sparking normally. Why the contradiction? > Shannen ------------------------------ Date: Sat, 15 May 1999 23:07:33 EDT From: ECMnut@xxx.com Subject: Re: I'm BACK...but NOW as a VENDOR Gar, It's good to hear from you. I & others were sorry to lose you way back when. Your posts were always "must reads" for the techies. Welcome back. (we locked the door after you entered this time) Mike V ------------------------------ Date: Sat, 15 May 1999 20:40:37 -0600 From: "Programmer" Subject: Re: BMFC, Tiiming, and Coatings Ted, It's been done in the past--I don't know if any real "dyno'd" results ever made some publications, but the best results wouldn't have made the extra work worth the bother. Lyndon - -----Original Message----- From: Stowe, Ted-SEA To: 'diy_efi@xxx.edu> Date: Saturday, May 15, 1999 12:40 AM Subject: RE: BMFC, Tiiming, and Coatings >here's a thought, has anyone ever given any thought to painting the inside >of an engine ? before you hit delete, consider how easy it is for dirt etc >to stick to the inside of the block, under a microscope the surface must be >like velcro. I suspect oil would return a little quicker to the pan. just a >thought, you can flame me now. > >-----Original Message----- >From: Bruce Plecan [mailto:nacelp@xxx.net] >Sent: Friday, May 14, 1999 9:31 PM >To: diy_efi@xxx.edu >Subject: BMFC, Tiiming, and Coatings > > >Has anyone run any "independent" testing on these barrier coatings for what >they actually have seen as an improvement pre+post coating?. > Has any one run any endurance tests?. >Do I need mention that this might need a complete recal to get right. >Bruce > ------------------------------ Date: Sat, 15 May 1999 20:45:11 -0600 From: "Programmer" Subject: Re: BMFC, Tiiming, and Coatings Greg, The only problem with testing like that is the motor had to be torn down to perform the experiment. I'd put little faith in a 15 degree change when a complete teardown would have had to be done to perform the work. Lyndon IP TECH - -----Original Message----- From: Greg Hermann To: diy_efi@xxx.edu> Date: Saturday, May 15, 1999 8:11 AM Subject: Re: BMFC, Tiiming, and Coatings >>Has anyone run any "independent" testing on these barrier coatings for what >>they actually have seen as an improvement pre+post coating?. >> Has any one run any endurance tests?. >>Do I need mention that this might need a complete recal to get right. >>Bruce > >A fellow I spoke with at HPC told me that they ran a dyno test of a fairly >typical hipo 350 CID Chebby first with no coatings, then with coating only >on the piston crowns. Said that--with no other changes, the steady state >oil temperature at sustained full load dropped 15 degrees F. > >Greg > > > ------------------------------ Date: Sat, 15 May 1999 21:46:12 -0600 From: bearbvd@xxx.net (Greg Hermann) Subject: Re: In cylinder pressure measurement >Recently, in our lab we have been using an optical transducer >(www.optrand.com) that measures the deflection of a flush-mounted diphragm >remotely with a tiny laser through an optical fiber. These currently cost >about $900 and don't need a charge amp. Future indications are that the >sensor electronics can be miniturized and the sensor produced at very low >cost. > Thanks for the details, Mark. This has got to be the one I had heard bit and pieces about. Regards, Greg ------------------------------ Date: Sat, 15 May 1999 23:53:54 -0400 From: "Bruce Plecan" Subject: Re: BMFC, Tiiming, and Coatings - ----- Original Message ----- From: Tom Sharpe To: Sent: Saturday, May 15, 1999 6:53 PM Subject: Re: BMFC, Tiiming, and Coatings Thanks, Bruce > Just seat of the pants measurements... medium hot 406 sbc, electric fan (on @ > 200), griffin radiator, 7 qt pan, with mild overheating problems... Idle in > traffic H2O @xxx. At 75 mph cruse, > lite load, H2O was 190-195, now 180, (thermostat), oil was 200-210 now 185. > Around Elkart lake for 1 hr, H2O @210, oil at 200, was 190, 190 before we were > back to the pits. tom S > > HPC has oil sheading coatings for crank, rods, block etc.. Tom S > > Bruce Plecan wrote: > > > Has anyone run any "independent" testing on these barrier coatings for what > > they actually have seen as an improvement pre+post coating?. > > Has any one run any endurance tests?. > > Do I need mention that this might need a complete recal to get right. > > Bruce > > > ------------------------------ Date: Sat, 15 May 1999 22:56:35 -0600 From: "Programmer" Subject: Re: O2 voltz Didn't see the original message, but ANY missfire ends up with a pulse wave of extra unburned fuel (and 14 parts of raw O2 stoich) by the O2 sensor. This lowers O2 voltage and increases injector pulse width. You end up EVERY time there's a missfire with a rich running engine. Hope this helps the explanation. Lyndon IP TECH - -----Original Message----- From: David A. Cooley To: diy_efi@xxx.edu> Date: Saturday, May 15, 1999 10:23 PM Subject: Re: O2 voltz >At 07:59 PM 5/15/99 -0400, you wrote: > >>Ok, please splain this statement. O2 sensor voltage drops when spark >>plugs fail to fire, and there's more HC present than when everything's >>sparking normally. Why the contradiction? > >My example was under conditions where combustion was actually happening. >Voltage will drop with increasing O2, but under combustion conditions, the >exhaust actually starts having more CO and HC as it get's richer and less O2. >=========================================================== > David Cooley N5XMT Internet: N5XMT@xxx.net > Packet: N5XMT@xxx. Member #7068 > Sponges grow in the ocean... Wonder how deep it would be if they didn't?! >=========================================================== ------------------------------ Date: Sat, 15 May 1999 23:16:36 -0700 From: garfield@xxx.com (Gar Willis) Subject: Re: SAAB DI coils - was Re: "ION" information ... On Sun, 16 May 1999 09:52:04 +1000, Peter Gargano wrote: >Well, 4862093 is a conceptial diagram, and certainly >good enough to describe what's happening, but the difference >between a conceptial circuit and an actual schematic >with transistor type numbers etc... > >I was wondering if anyone has had a look at a real SAAB >ION-sense module and come up with a real schematic. I ask >this because I read in the archives that there were a few >of these SAAB modules floating around (some time ago) and >someone was going to check it out (but I could find no >reference of this actually happening). Jim Crance's >email made me wonder if the modules he has are the ION-sense >versions. Tisk tisk, you musta missed some of the article contents, cuz I related how I HAD unpotted a SAAB assembly, traced the circuit, and discovered MUCH to my surprise that the patent circuit was almost identical to the actual wiring of the mfg'd part. I was about to publish a list of parts values to accompany their patent circuit, when Robutt Hairass threatened to see if he couldn't stir up SAAB's legal department to sue me for infringement, even tho the exploration we were doing was COMPLETELY within both the spirit and letter of patent law. (There's a discussion of this 'playing with patents' and why/how it's perfectly legal AND ethical in the archives, I'd recomment you peruse). Because nobody came to my defense when I posted his threats publically and complained, I decided to demure on handing out the goodies. Just one of life's many 'realities'. All this histery (sic) is in the archives if you care to look. Only other 'problem' is that the circuit in the patent is NOT the circuit in their later/current versions, but only in the one they used to introduce the technology in '90. By 1992 (the only revision they've had in all the subsequent years!), they had gone to a newer design, which was never published, to my knowledge. >I also understand that the later SAAB ION-sense modules >are potted and impossible to actually get into. ALL the SAAB systems are of necessity potted. They're not tryna hide anything; it's needed due to the nature and packaging of the system. But concerning "potted and impossible", that's a misconception. ANY potted system can be "gotten into" with the right chemicals and techniques, but you may efface so much of the ID info on the parts that you really have a detective job on yer hands, even tho you indeed have the parts wiring. The more chips in there, the more this obtains. IF Saab actually had wanted to hide their largely analog circuitry via potting (which the patent's disclosure of the actual circuit seems to prove otherwise, on the face of it), they would have just integrated key parts of the circuit in an analog partition that could NOT be viewed without sophisticated chip reversing equipment, which is eXactly what has been done with the EGOR module, and will also be done with the IONeyes module. >Anyway, I don't really want a SAAB module, but a real >life schematic of an ION-sense circuit so I can start >playing with it on my 68HC11 ignition controller. Yes, understandable; exactly! Just give us a couple months and you'll be able to license just such a circuit and PLANS from us FOR PERSONAL USE ONLY, including the none-too-trivial HV supply and CDI-like IGN system that MUST accompany any such IONeyes attempts. The reason for the last statement is that the IGN event has to be kept short enough to close off quickly and open the window for ION to look into the combustion chamber. Standard inductive IGN is simply WAY too long-lived an event, and can completely mask the most important time period needed to inspect for a detonation signature. You will of course need to buy an IONeyes module from us (it WILL be nominally priced) in order to use the PLANS and to implement the other key parts of the circuit, but beyond that, there's a GREAT deal to layer onto that, in order to build up a complete engine/boost management system, which includes IONeyes, EGOR, and IGN advance control. Once those pieces are integrated together, you'll at long last have a complete WOT proformance engine management ability, because for the first time, you'll have misfire/detonation/preignition detection you CAN rely on, and WOT O2 measurement. This, AFAIK, will be the first time a hobbyist person will safely be able to push the envelop in terms of AFR tuning and forced induction. Dr. Pelican I believe some time ago was the only one I've seen to realize and make this estute observation, that EGOR & AFR measurement is wunnerful, but it's all dressed up with nowhere to go, if you don't ALSO have a reliable method to determine/predict the onset of detonation. If you don't have that last ION piece (or have reliable acoustic detection, of course), you may know what the AFR is precisely, but you still don't know WHAT AFR is safe until after the fact, and after the detonation damage is done. Gar ------------------------------ Date: Sun, 16 May 1999 03:44:32 EDT From: Regnirps@xxx.com Subject: Re: O2 voltz In a message dated 5/15/99 10:08:53 PM, nacelp@xxx.net writes: > Staff been to market 3x today looking for cereal cables, we're > >committed to finding them thou..(well maybe commitable) According to my Dad, "cerial cables" are what you get if you eat too much fiber. During the great oat bran craze he warned his friends about the possibility of rope burn : ) Charlie Springer ------------------------------ End of DIY_EFI Digest V4 #286 ***************************** 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".