DIY_EFI Digest Wednesday, 31 July 1996 Volume 01 : Number 216 In this issue: Re:toothed wheels for crankshaft position sensing Re: Proper Mixture. efi332 Re: Color Tune Re: Proper Mixture. Re: Proper Mixture. Re: Color Tune source Circuits for magnetic pickups Re: Proper Mixture. Re: water injection questions Re: Circuits for magnetic pickups Re: toothed wheels for crankshaft position sensing Re: Proper Mixture. Re: Proper Mixture. Re: Color Tune source Re: Circuits for magnetic pickups NipponD question See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Markus Strobl Date: Tue, 30 Jul 1996 10:34:04 -0500 Subject: Re:toothed wheels for crankshaft position sensing > >And what is the benefit of the many (50+) toothed sensor? Is it durability > >without maintenance, simplification of hardware, or is there some benefit > >which I am missing? > > Wouldn't have much effect on durability, since you need the sensors no > matter how many teeth there are, nor would it affect the hardware complexity > from an electronic standpoint. Main benefit is increased resolution. You > can calculate rate of change of RPM, acceleration, etc. much more accurately > the more often you sample the crank position. It also requires some more > processor overhead, but a lot of the newer processors have self contained > timer systems that do it all with very little processor intervention. Hmm.. My '96 Z28 has: 1... 180 tooth wheel on the camshaft (called hi-res signal in manual). 2... 4 tooth wheel on camshaft (called Lo-res signal). 3... 4 tooth wheel on crankshaft (CPS). Does Ford still use 58 toothed sensors or have they increased like GM, and why would anyone need 180 teeth in the first place? 'confused' Markus ------------------------------ From: tom sparks Date: Tue, 30 Jul 1996 11:11:36 -0500 Subject: Re: Proper Mixture. John: Here is a web page that will probably answer some of your questions about the O2 sensor: http://ram.chem.tulane.edu:8080/f-body/trivia/o2sensor.html From what I've been able to gather, the O2 sensor found on modern cars is really only good for a narrow band of A/F ratios, so narrow in fact that it is really only able to tell you if you are over or under the optimum. Again from what I've gathered, this is used to adjust the injector pulse width slightly until the mix is a little too far the other way. So, the A/F mix hovers close to stoich but never really stays on stoich too long. Nother thing. The O2 sensor is some distance from the injector and what is going on between the two places may bear no relation to either of them. In other words, the O2 sensor tells you what already happened some time ago and the system is left to make some sense of it in real time. BTW, what injectors are you using for a motor that small and what kinds of rail pressures are you using? Best regards, Thomas Sparks At 09:56 7/29/1996 PDT, you wrote: >Hi, > >Newbie type question again. > >I'm working on improving a 2HP Briggs&Stratten Lawnmower engine. I have the >electronic ignition complete and when I finish the TDC/BDC sensor disk I'll >try it. As it is it works with a simulator that produces the pulses that >the sensors would make. So I can see a nifty advance curve working all the >way up to 3600 RPM. > >Next is to improve the fuel delivery. But How do I know what the optimum >mixture should be at any RPM under load. Do I purchase an O2 Sensor that >goes in the exhaust? I have a color tune spark plug and I can use it to set >idle mixture by looking through the quartz window in the sparkplug and >adjusting for blue ignition; too rich is yellow/orange. However this >sparkplug would destruct under continuous operation at 3600 RPM. > >Tom Cloud mentioned that he had an Oxygen sensor that he monitored under >cruise. It's no big deal to add a 12 bit A/D to my processor and read the >voltage value. Question is.... how do I interpret this? > >I can see if there is zero O2 left then I have complete combustion for the >amount of O2 in the intake stroke but if I have a too rich mixture wouldn't >that happen anyway? > >Thanks, > >John. >Pioneers are the ones, face down in the mud, >with arrows in their backs. >Automation Artisans Inc. Ph. 604-544-4950 >6468 Loganberry Place Fax 604-544-4954 >Victoria BC CANADA V8Z 7E6 > > > ------------------------------ From: Robert Van Zant Date: Tue, 30 Jul 1996 11:39:00 -0500 Subject: efi332 Couple of questions. www.cim.swin.edu.au/~adel/(rest of path) appears dead. Is this still the best route to efi332 stuff? efi332 mailing list also seems a bit spotty. Still alive? Are there any other projects related to efi and distributorless ignition floating around the net. So far I've found efi332, and ddis. thanks, bob ------------------------------ From: agc@xxx. Chichak) Date: Tue, 30 Jul 1996 11:36:41 -0600 Subject: Re: Color Tune At 08:45 7/30/96, Hans Hintermaier wrote: >John Dammeyer wrote: > >Can anybody tell me something about the colortune spark plug ? >(manufactor, price) I know it only as glow plug for model engines and >have never heared about spark plugs with the same feature. >Thanks >Hans >hiha@xxx.de >Munich / Germany You see, John knows what he is talking about since he has two color tunes (hi boss). A color tune is made in the UK by a company called Gunson. It replaces your spark plug during your testing, has a quartz glass window that the centre electrode passes through. When the mixture in the cylinder burns you can see the color of the flame. They are available at specialty shops like Moss Motors in US or MiniMania, Se7en Enterprises, or other brit bits places. Last time I bought one I paid about $CDN40 (which is about a buck and a half US these days :-) I have used this beast to tune my Mini, VW Rabbit GTi (with O2 sensor disabled), rototiller, and 2 cycle lawnmower (the color changes slightly due to the oil). Aaach, they're brilliant. Go out and buy one, and a Volvo 850 as well. A - -- Andrei Chichak | Information Systems agc@xxx.ca | University of Alberta Hospitals (403) 492 - 4431 (work) | CSB 8-120 (403) 492 - 3090 (fax) | 8440 112 Street Edmonton, Alberta http://cooper-s.uah.ualberta.ca | CANADA T6G 2B7 ------------------------------ From: Markus Strobl Date: Tue, 30 Jul 1996 13:24:07 -0500 Subject: Re: Proper Mixture. > From what I've been able to gather, the O2 sensor found on modern cars is > really only good for a narrow band of A/F ratios, so narrow in fact that it > is really only able to tell you if you are over or under the optimum. Again > from what I've gathered, this is used to adjust the injector pulse width > slightly until the mix is a little too far the other way. So, the A/F mix > hovers close to stoich but never really stays on stoich too long. > Thomas Sparks I wonder if this has changed in the last few years? when I tune my Z28, I tune it by adjusting fuel pressure until I get about 890-920 mV from the O2 sensors. This corresponds to about 13:1 A/F ratio. Interesting note about GM PCMs: If the fuel pressure (FP) is increased above 40 PSI, the block learn for idle and cruise will start going to less than 128 (effectively leaning the mixture). However WOT block learn will *never* go under 128, and the WOT mixture will be rich. On the other hand if FP is decreased below 40PSI the block learn will increase for idle and cruise to compensate but *also for WOT*, keeping WOT O2 readings in the 890-920 mV range. Man, I'd love to see that source code! IF someone at delco is listening send it to me and I'll be your life long friend! :-) - ------- Markus '96 Z28 w/ mods. Proof that OBDII is not the end of performance. ------------------------------ From: atsakiri@xxx.com Date: Tue, 30 Jul 96 14:52:00 -0400 Subject: Re: Proper Mixture. > > from what I've gathered, this is used to adjust the injector pulse width > > slightly until the mix is a little too far the other way. So, the A/F mix > > hovers close to stoich but never really stays on stoich too long. > > I wonder if this has changed in the last few years? when I tune my Z28, > I tune it by adjusting fuel pressure until I get about 890-920 mV from > the O2 sensors. This corresponds to about 13:1 A/F ratio. I don't think this has changed. At least two factors are 1) the drift of the sensor's characteristics over time, and 2) the sensor- to-sensor variation. I think most fuel controllers are of the bang-bang variety. (That's not to say that something else won't work!) Anthony Tsakiris - --------------------------------------------------------------------------- The opinions expressed are my own and not necessarily those of my employer. ------------------------------ From: Doug Rorem Date: Tue, 30 Jul 1996 14:49:21 -0500 Subject: Re: Color Tune source >> Subject: Re: Color Tune >> >> At 08:45 7/30/96, Hans Hintermaier wrote: >> >John Dammeyer wrote: >> >> >> >> > >> >Can anybody tell me something about the colortune spark plug ? >> >(manufactor, price) I know it only as glow plug for model engines and >> >have never heared about spark plugs with the same feature. >> >Thanks >> >Hans >> >hiha@xxx.de >> >Munich / Germany >> >> >> You see, John knows what he is talking about since he has two color tunes >> (hi boss). A color tune is made in the UK by a company called Gunson. It >> replaces your spark plug during your testing, has a quartz glass window >> that the centre electrode passes through. When the mixture in the cylinder >> burns you can see the color of the flame. They are available at specialty >> shops like Moss Motors in US or MiniMania, Se7en Enterprises, or other brit >> bits places. Last time I bought one I paid about $CDN40 (which is about a >> buck and a half US these days :-) >> >> I have used this beast to tune my Mini, VW Rabbit GTi (with O2 sensor >> disabled), rototiller, and 2 cycle lawnmower (the color changes slightly >> due to the oil). >> >> Aaach, they're brilliant. Go out and buy one, and a Volvo 850 as well. >> >> A >> >> -- >> Andrei Chichak | Information Systems >> agc@xxx.ca | University of Alberta Hospitals >> (403) 492 - 4431 (work) | CSB 8-120 >> (403) 492 - 3090 (fax) | 8440 112 Street Edmonton, Alberta >> http://cooper-s.uah.ualberta.ca | CANADA T6G 2B7 >> The colortune tester is also available from Rapid Parts in New York (914)-352-1138. The part number I have is 000-265678863 ( $55.95 in their old price book). I was thinking about getting one myself. - -- Doug Rorem University of Illinois at Chicago (312)-996-5439 [voice] EECS Department RM 1120 (312)-413-1065 [fax] 851 S. Morgan Street (708)-996-2226 [pager] Chicago, IL 60607-7053 rorem@xxx.edu ------------------------------ From: "Tony Bryant" Date: Wed, 31 Jul 1996 08:43:51 +1200 Subject: Circuits for magnetic pickups I'm using the following circuit for my inductive pickups: LM3900 norton op amp, 10K +5v---/\/\/\------(inverting) +5v---/\/\/\------+-------(noninverting) (output) 10K | | \---/\/\/\---------------/ 470K seems to work relatively well, but it suffers from the occasional extra pulse (noise I assume). The requirements I had when designing this circuit were: 1) circuit is stable, when pickup is not picking up (i.e. it needs hysteresis) 2) I can pickup both approaching & receeding teeth (i.e the output should be a squared up version of the pickup current) 3) 5V only supply My question is what are other people using? *********************************************************** * There'll be no more misery * I came, I saw, I left * * When the world's our rotisserie * > bryantt@xxx.nz < * *********************************************************** ------------------------------ From: cloud@xxx.edu (tom cloud) Date: Tue, 30 Jul 1996 16:20:32 -0500 Subject: Re: Proper Mixture. >John: > >Here is a web page that will probably answer some of your questions about >the O2 sensor: > >http://ram.chem.tulane.edu:8080/f-body/trivia/o2sensor.html > > From what I've been able to gather, the O2 sensor found on modern cars is >really only good for a narrow band of A/F ratios, so narrow in fact that it >is really only able to tell you if you are over or under the optimum. Again >from what I've gathered, this is used to adjust the injector pulse width >slightly until the mix is a little too far the other way. So, the A/F mix >hovers close to stoich but never really stays on stoich too long. > >Nother thing. The O2 sensor is some distance from the injector and what is >going on between the two places may bear no relation to either of them. In >other words, the O2 sensor tells you what already happened some time ago and >the system is left to make some sense of it in real time. > >BTW, what injectors are you using for a motor that small and what kinds of >rail pressures are you using? > >Best regards, >Thomas Sparks > > A simple and effective indicator for O2 sensor is a DPM (digital panel meter) from Hosfelt Electronics. It is $14.95, their part number 39-165 (the part no. on the data says PM-128). It uses an Intersil ICL7106 DMM chip with a fairly standard wiring. There is one problem -- they have connected the supply voltage common with the input common, which can cause ground loop problems -- I solve this by using a 9 volt battery (actually I was lazy and that was just the fastest way for me to get it up and running). The 9 volt battery lasts about 6 months. One could use a simple resistor and zener or LM-317 to run it off the 12 - 14 volt battery system (I don't think it wise to run it straight off the auto's battery system). It is 3-1/2 digits and can be wired to read 0-2 volts (the lit. is poor, so if anyone has a problem, I can tell you how to wire it for this range). The O2 sensor output is 0 to about 1 volt, with about .5 volt being stoichiometric (14.7:1 A/F) and more fuel (lower A/F, higher F/A) producing more voltage. The sensor output is Hi-Z and the DPM is rated > 100 M ohm input Z, so it's ideal for this app. On my '82 Bronco with the sensor in standard location (about 6 or 8" downline from the manifold), the sensor gets warm enough to give a reading in a minute or so and allows me to have some semblance of control and repeatability over my Holley TBI system. Hosfelt Electronics: 800-524-6464 (FAX 800-524-5414) $14.95, their part number 39-165. Tom Cloud ------------------------------ From: "George M. Dailey" Date: Tue, 30 Jul 1996 18:46:49 -0500 Subject: Re: water injection questions At 10:39 PM 7/24/96 -0400, you wrote: >In a message dated 96-07-23 18:46:17 EDT, you write: > >>How would GM EST react to this situation? On my 89 TPI set up, I noticed >>that after running high octane fuel for a week and then switching to the >>cheap stuff, if I floored the throttle I would hear a few detonations and >>the check engine light would come on. Code 43 EST. After two or three times >>of this, it would start working normally. Does it take the ECM this long to >>adjust. >> >>GMD > >No. The ECM does not adjust (as in learn) at all in this application. But >it should not get the error code 43. Is the wire shorted? This error would >indicate one of two things. Either it never knocks, or it senses knock all >the time..... > >Scot Sealander FIScot@xxx.com Scott, the wire is definitly not shorted. The system works as it should except as noted above. I've been burning the cheap stuff continously now for several months. I have had no EST or ESC related codes and I punch it frequently. "... hard acceleration reduces frustration...!". The situation I presented is accurate, I'm just not sure of the reason. Mabey the ECM expected to hear detonation at a certain condition and set a code as a result. I could definitly hear the detanation (sounded like a handfull of bolts in an empty can). After the code set, the ECM would not advance the timing (full throttle advance) untill engine shutdown. I believe this because, if you nailed it again, power would be down and no knock could be herd. ????? GMD ------------------------------ From: Gary W Harris Date: Tue, 30 Jul 96 17:26:00 PDT Subject: Re: Circuits for magnetic pickups Text item: You might also look at using the National LM1815 Adaptive Variable Reluctance Sensor Amplifier chip. It is inexpensive (well, $5.70 from DigiKey) and operates over an input voltage range of 100mV to 120V! Check it out! Gary I'm using the following circuit for my inductive pickups: LM3900 norton op amp, 10K +5v---/\/\/\------(inverting) +5v---/\/\/\------+-------(noninverting) (output) 10K | | \---/\/\/\---------------/ 470K seems to work relatively well, but it suffers from the occasional extra pulse (noise I assume). The requirements I had when designing this circuit were: 1) circuit is stable, when pickup is not picking up (i.e. it needs hysteresis) 2) I can pickup both approaching & receeding teeth (i.e the output should be a squared up version of the pickup current) 3) 5V only supply My question is what are other people using? *********************************************************** * There'll be no more misery * I came, I saw, I left * * When the world's our rotisserie * > bryantt@xxx.nz < * *********************************************************** Text item: External Message Header The following mail header is for administrative use and may be ignored unless there are problems. ***IF THERE ARE PROBLEMS SAVE THESE HEADERS***. Reply-To: diy_efi@xxx.edu Precedence: bulk Sender: owner-diy_efi@xxx.edu Message-ID: <112BFA26CE4@xxx.nz> X-mailer: Pegasus Mail for Windows (v2.42) Priority: normal Subject: Circuits for magnetic pickups Date: Wed, 31 Jul 1996 08:43:51 +1200 To: diy_efi@xxx.edu Organization: Fisher & Paykel PSC From: "Tony Bryant" Received: from SpoolDir by SCRATCHY (Mercury 1.30); 31 Jul 96 08:43:56 +1100 Received: from SCRATCHY/SpoolDir by scratchy.fp.co.nz (Mercury 1.21); 31 Jul 96 08:44:14 +1100 Received: from scratchy.fp.co.nz by minor.fp.co.nz (SMI-8.6/SMI-SVR4) with ESMTP id IAA28068 for ; Wed, 31 Jul 1996 08:4 3:04 +1200 Received: from minor.fp.co.nz (fpmail.fp.co.nz [202.12.105.12]) by stimpy.fp.co. nz (8.7.5/8.7.3) with SMTP id IAA22809 for ; Wed, 31 Jul 1996 08:43:20 +1200 (NZST) Received: from stimpy.fp.co.nz by coulomb.eng.ohio-state.edu via ESMTP (940816.S GI.8.6.9/940406.SGI) for id QAA28485; Tue, 30 Jul 1996 16:4 3:40 -0400 Received: by coulomb.eng.ohio-state.edu (940816.SGI.8.6.9/940406.SGI) id UAA28490; Tue, 30 Jul 1996 20:43:47 GMT Received: from coulomb.eng.ohio-state.edu (coulomb.eng.ohio-state.edu [128.146.9 0.150]) by ormail.intel.com (8.7.4/8.7.3) with SMTP id PAA11233 for ; Tue, 30 Jul 1996 15:12:55 -0700 (PDT) Received: from ormail.intel.com (ormail.intel.com [134.134.248.3]) by relay.jf.i ntel.com (8.7.4/8.7.3) with ESMTP id PAA20947 for ; Tue, 30 Jul 1996 15:12:54 -0700 (PDT) Return-Path: owner-diy_efi-outgoing@xxx.edu ------------------------------ From: KMJMS@xxx.com Date: Tue, 30 Jul 1996 21:36:48 -0400 Subject: Re: toothed wheels for crankshaft position sensing ford never used 58 teeth they what is called 36-1 teeth for EEC 4 and 5 EEC 3 systems used 4 teeth kirk ------------------------------ From: FIScot@xxx.com Date: Tue, 30 Jul 1996 22:04:04 -0400 Subject: Re: Proper Mixture. In a message dated 96-07-30 14:54:03 EDT, you write: >On the other hand if FP is decreased below 40PSI the block learn will >increase for idle and cruise to compensate but *also for WOT*, keeping >WOT O2 readings in the 890-920 mV range. This is very easy to do with only a couple lines of code. If in PE and and the BLM is above hex '80' go ahead and add fuel. If BLM is under hex '80' , skip BLM adjust... >Man, I'd love to see that source code! IF someone at delco is listening >send it to me and I'll be your life long friend! :-) You will have to disassemble it yourself...... :-) Scot Sealander FIScot@xxx.com ------------------------------ From: John Dammeyer Date: Tue, 30 Jul 96 20:39 PDT Subject: Re: Proper Mixture. At 04:20 PM 30/07/1996 -0500, you wrote: >>John: >> >>Here is a web page that will probably answer some of your questions about >>the O2 sensor: >> >>http://ram.chem.tulane.edu:8080/f-body/trivia/o2sensor.html Great WEB page!!!! >> > >>BTW, what injectors are you using for a motor that small and what kinds of >>rail pressures are you using? I haven't decided if I want to inject that small a motor. The choices are Propane, Gasoline with a variable venture (ie: throttle slide), a miniature SU carb or injection. Injection sounds like an interesting project but then I would need to worry about a fuel pump that delivers at least 45PSI. The injector could be just about anything I guess as the time interval is the important part. I'll probably start with a simple throttle slide carb so that I can instrument and develop some baseline information on mixture etc. If a cheap fuel pump would show up, well, then perhaps injection would be fun. John. Pioneers are the ones, face down in the mud, with arrows in their backs. Automation Artisans Inc. Ph. 604-544-4950 6468 Loganberry Place Fax 604-544-4954 Victoria BC CANADA V8Z 7E6 ------------------------------ From: John Dammeyer Date: Tue, 30 Jul 96 20:39 PDT Subject: Re: Color Tune source At 02:49 PM 30/07/1996 -0500, you wrote: >> > >The colortune tester is also available from Rapid Parts in New York (914)-352-1138. >The part number I have is 000-265678863 ( $55.95 in their old price book). >I was thinking about getting one myself. > >-- >Doug Rorem Actually I have only one. I borrowed the other when I had a '64 MGB. The two and a UniSyn airflow guage let me balance the carbs really nicely. Well, the UniSyn and the other Colortune 500 went back to their owner after I got rid of the B. BTW. I bought it at Halfords back in 1977 for 6.55 Pounds Sterling. (about 14 Cdn Dollars) Of course in 1972 I bought a brand new datsun 510 for only $2600. sigh.... John. Gunson's Color Plugs Limited 66 Royal Mint Street London E1 8LG Don't know if they're still around but that's the address from the package. Pioneers are the ones, face down in the mud, with arrows in their backs. Automation Artisans Inc. Ph. 604-544-4950 6468 Loganberry Place Fax 604-544-4954 Victoria BC CANADA V8Z 7E6 ------------------------------ From: Darrell Norquay Date: Tue, 30 Jul 96 21:44 PDT Subject: Re: Circuits for magnetic pickups At 08:43 AM 7/31/96 +1200, Tony Bryant wrote: >I'm using the following circuit for my inductive pickups: The circuit I've seen using the LM3900 is: +V 0 R1 - 5M | R2 - 200K R1 R3 - 200K | |\ R4 - 10M | | \ R5 - 5M P----R2--+----|- \ I | \ C | \__________ K | / | U | / | P----R3--+----|+ / | | | / | | |/ | +--------R5------+ | R4 | 0 +V This was for use with a magnetic reluctor type pickup. This will give hysteresis, as well as a nice square wave out. You might try a few hundred pF cap across the pickup, and about a .01uF from the pickup side of R2 to ground. This may improve the input noise immunity. regards dn dnorquay@xxx.com ------------------------------ From: Michael Kent Date: Wed, 31 Jul 1996 00:51:29 -0700 (PDT) Subject: NipponD question Has anyone modified ND injection systems? Specifically later model units (90->) with port injection, DIS, etc. I'm looking for some advice as to firmware/rom tables, structure. Thanx MK ------------------------------ End of DIY_EFI Digest V1 #216 ***************************** 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".