DIY_EFI Digest Tuesday, 30 July 1996 Volume 01 : Number 215 In this issue: Re: toothed wheels for crankshaft position sensing Idle Strategy. Re: OBD-II toothed wheels for crankshaft position sensing Holley FI Re: OBD-II toothed wheels for crankshaft position sensing Citroen BX - Bosch EFI Re: Holley FI 58-tooth wheels Re: OBD-II toothed wheels for crankshaft position sensing Re: Idle Strategy. Re: OBD-II toothed wheels for crankshaft position sensing Re: Holley FI Ford distributor cam position sensors Re:toothed wheels for crankshaft position sensing Proper Mixture. Color Tune See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Jeffrey.Giberstein@xxx.EDU (Jeffrey Giberstein) Date: 29 Jul 96 08:36:56 EDT Subject: Re: toothed wheels for crankshaft position sensing Another # for Haltech: 214-831-9800 Electromotive does get grumpy when you try to buy stuff from them. I don't know why... Haltech (actually called Enjectech now) is based somewhere in Texas. Good luck! Jeff ------------------------------ From: "Lamari, Matthew" Date: Mon, 29 Jul 96 10:42:00 PDT Subject: Idle Strategy. Could anyone tell me a good way to handle startup to idle, I understand there are a couple of ways. I believe I've seen a system where idle speed is set with a base throttle opening, then modifies amount of fuel to hold idle. Another with an idle control over air as well. How should the fuel be mixed on startup? Is cranking a matter of throwing in heaps of fuel on startup? Is engine speed an adequate feedback variable to hold idle by modulating fuel? Is EGO even a consideration when starting/idling, or could cold temperature render it useless? How relevant is intake/block temperature to all of this? In short, what's a good way to handle idle? thanks, Matthew Lamari mlamari@xxx.com ------------------------------ From: cloud@xxx.edu (tom cloud) Date: Mon, 29 Jul 1996 11:32:56 -0500 Subject: Re: OBD-II toothed wheels for crankshaft position sensing >Thanks. I'm adapting a home brew system to a 1992 5 Liter Ford Mustang >engine. I'll look around and find out if Ford has a crankshaft position >sensor for their 5 or 5.8 Liter engines. Does anyone know if they do?? > >-Jeff Fisher > I have an '82 Bronco with 351-W with crank sensor. My son has an '86 with a 302 and the same sensor setup. ------------------------------ From: cloud@xxx.edu (tom cloud) Date: Mon, 29 Jul 1996 11:46:56 -0500 Subject: Holley FI I would like to hear from anyone with any experience with the Holley after market throttle body injection units. I am currently using their 650 cfm unit w/out EGO feedback (i.e. plain speed density using only RPM, TPS and engine temp. for operating parameters) It has bought me a 50% increase in MPG (from 8 to 12) over my worn out stock variable venturi carb (on an '82 Bronco) and works quite well. ------------------------------ From: Jeff Fisher Date: Mon, 29 Jul 1996 12:57:47 -0700 Subject: Re: OBD-II toothed wheels for crankshaft position sensing At 09:41 PM 7/28/96 -0400, you wrote: >fomoco went to a dis system for the 5.0 engine in the explorer >it uses what they call 36-1 toothed wheel >kirk > Great! I'll get one of those... Thanks, Jeff ------------------------------ From: "Armando Carrapico" Date: Mon, 29 Jul 1996 19:24:32 GMT+100 Subject: Citroen BX - Bosch EFI Dear friends, I writing from Portugal, and this is my first mail to you. I know that this group is essencialy created to discuss new improvements to the systems, but in my case I am for the moment, interested in geeting my car with the best performance/comsuption possible. The thing is that I have bougt the car in 2nd hand last year and so far no one seems to be able to tune the car well, specialy the guys from Citroen. I like the car a lot but I dont know even what are the function of the tuning elements that they change, or the sensor readers. The car is a Citroen BX GTi 1600cc from 1990 and is 113000Km. There are an hexagonal 6mm screw near the air filter and another screw which I thougt was the idle regulator, but may not, near the air admitance collector. Could you tell me how to find some information on what type of System I have (There is a Bosch box under the left seat) and how to tune it, something like turning the screw X to right the mixture became ritcher, etc. Thank you very much for everything you may add to this matter. Armando Carrapico. ------------------------------ From: brewer@xxx.com (John Brewer) Date: Mon, 29 Jul 1996 15:33:32 -0500 Subject: Re: Holley FI >I would like to hear from anyone with any experience with the Holley >after market throttle body injection units. > >I am currently using their 650 cfm unit w/out EGO feedback (i.e. >plain speed density using only RPM, TPS and engine temp. for operating >parameters) It has bought me a 50% increase in MPG (from 8 to 12) over >my worn out stock variable venturi carb (on an '82 Bronco) and works >quite well. I wonder if I could use it to improve the MPG on my Toyota Land Cruiser. Does it have a means for using MAF. I am currently working (thinking) on a self-designed multi-port, MAF, based EFI unit. A Holley throttle body unit might be an excellent intermediate measure- learning curve and all that sort of thing you know... Any idea whether or not they come in other CFM ratings, 650 is probably too big for a 258cid straight six. John Brewer "Any man who would trade liberty for security deserves neither." - Ben Franklin ------------------------------ From: Jim Steck <72614.557@xxx.COM> Date: 29 Jul 96 16:39:13 EDT Subject: 58-tooth wheels > Why everybodies obsession with external 58 toothed wheels?, you do > realise that you already have a 120 odd tooth wheel already bolted to > the back of the engine?. (Yes, I do realise you also need a TDC reference) Don't try to use a magnetic pickup with a starter ring gear . . . there is too much dirt generated by the wear of the starter and ring gear for it to work very long. Jim Steck AutoComponenti ------------------------------ From: "Lamari, Matthew" Date: Mon, 29 Jul 96 16:15:00 PDT Subject: Re: OBD-II toothed wheels for crankshaft position sensing I participated in the construction of an ECU that fully controlled the ignition (didn't get to fuel) of a car. We drove the thing around and all was cool. It comprised an advance table. The crank sensor wheel had 2 sensors on it, that is, an event was generated every half rev. When to actually spark was done relative to this. Knowing in time base the advance to use in a situation corresponded to delays from this point, which use of interrupts could catch in time (the thing ran as well as with its archaic stock ignition.) We were also going to implement a backup mode whereby the system could run with only one functional. But what we had was effectively a 2 tooth wheel. Position in the cycle can be guessed from the time since the last signal and the wheel's effective speed, or time to reach a position predicted. Of course, acceleration and deceleration make the previously measured speed inaccurate; but the wheel is spinning so fast and accelerating so comparitively slowly that the difference from one sample to the next isn't that great. Okay, we had output compare functionality on the microprocessor to spark right on time. I don't know where my colleague got his hands on this sensor (magnetic) but are they available? 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? Thanks. Matthew Lamari, mlamari@xxx.com ------------------------------ From: peter paul fenske Date: Mon, 29 Jul 1996 14:39:44 -0700 Subject: Re: Idle Strategy. At 10:42 AM 7/29/96 PDT, you wrote: > > >Could anyone tell me a good way to handle startup to idle, I understand >there are a couple of ways. > >I believe I've seen a system where idle speed is set with a base throttle >opening, then modifies amount of fuel to hold idle. Another with an idle >control over air as well. > >How should the fuel be mixed on startup? Is cranking a matter of throwing >in heaps of fuel on startup? Usually the Idle Air motor is set to open to a predetermined opening position 144 steps or so from closed in a gm system. Then a certain pulsewidth is used to get a fairly rich start up mixture. There is usually a table with pulsewidth(a/f ratio) to start up temp. Also a clear choke function is used. Above 80% throttle opening during startup the injectors are shut down. Injectors are usually assynchronous(not always) since there can be a long time between injections at low starting rpm. Transition to runmode can be handled in a number of ways. Use a table of number of engine revs to temp. Or a set rpm can be obtained before switching to run mode. Then idle control is used to obtain a predetermined rpm based on a temp lookup. > >Is engine speed an adequate feedback variable to hold idle by modulating >fuel? Only when very hot. Usually closed loop after a certain operating temp or a time period has passed. > >Is EGO even a consideration when starting/idling, or could cold temperature >render it useless? > Ego has to be quite hot. Even electrically heated ones take some time to work. >How relevant is intake/block temperature to all of this? > >In short, what's a good way to handle idle? Lookup table of idle speed to temp. Offsets for P/N, airconditioning, overtemp ect. Also reset Iac every so often. And use a relatively slow control loop. Even so oscillations happen. > > >thanks, >Matthew Lamari >mlamari@xxx.com > GL: peter ------------------------------ From: peter paul fenske Date: Mon, 29 Jul 1996 14:41:46 -0700 Subject: Re: OBD-II toothed wheels for crankshaft position sensing At 11:32 AM 7/29/96 -0500, you wrote: > >>Thanks. I'm adapting a home brew system to a 1992 5 Liter Ford Mustang >>engine. I'll look around and find out if Ford has a crankshaft position >>sensor for their 5 or 5.8 Liter engines. Does anyone know if they do?? >> >>-Jeff Fisher >> > >I have an '82 Bronco with 351-W with crank sensor. My son has an '86 with >a 302 and the same sensor setup. > You should have a PIP signal available from the ignition module which will tell you number 1 fire. Ford needs this since their system is sequential esp in the stang : peter ------------------------------ From: cloud@xxx.edu (tom cloud) Date: Mon, 29 Jul 1996 18:20:51 -0500 Subject: Re: Holley FI >>I would like to hear from anyone with any experience with the Holley >>after market throttle body injection units. >> >>I am currently using their 650 cfm unit w/out EGO feedback (i.e. >>plain speed density using only RPM, TPS and engine temp. for operating >>parameters) It has bought me a 50% increase in MPG (from 8 to 12) over >>my worn out stock variable venturi carb (on an '82 Bronco) and works >>quite well. > >I wonder if I could use it to improve the MPG on my Toyota Land Cruiser. >Does it have a means for using MAF. I am currently working (thinking) on a >self-designed multi-port, MAF, based EFI unit. A Holley throttle body unit >might be an excellent intermediate measure- learning curve and all that >sort of thing you know... Any idea whether or not they come in other CFM >ratings, 650 is probably too big for a 258cid straight six. > >John Brewer > > >"Any man who would trade liberty for security deserves neither." - Ben >Franklin > > John I don't sell Holley -- or anything else -- but you should contact them and get their catalog. They make several types of EFI units, mine being the most basic and cheapest, about $600. I bought it because I had already tried the carburetor route with little improvement and didn't want to continue to throw money down that hole. I thought (and still think) that this is a very reasonable way to do sort of what you said -- get started and improve upon it. No, the unit I have only has a $200 option to add EGO sensor feedback. It is nice in that the analog controls are in the cockpit with you. I have a digital voltmeter on an oxygen sensor that I use to see how it is working in cruise. Under acceleration (apparently determined by TPS vs. RPM) the A/F ratio gets low (EGO output approches 1 volt). As far as other cfm ratings, there are several variations which are approved replacements for various auto model's TBI systems and they are lower cfm. (I don't have Holley's number, etc. at hand, but their tech. support number is 502-781-9741 (9:30-11:30 & 12:30-3:30. Sorry, don't know time zone, though I think it's CST. I also don't recommend the tech. line unless you have a long time and lots of money for LD charges.) Tom Cloud ------------------------------ From: Jeff Fisher Date: Mon, 29 Jul 1996 21:50:34 -0700 Subject: Ford distributor cam position sensors >>I have an '82 Bronco with 351-W with crank sensor. My son has an '86 with >>a 302 and the same sensor setup. >> >You should have a PIP signal available from the ignition module which will >tell you number 1 fire. Ford needs this since their system is sequential >esp in the stang >: peter > > Peter, Yes, my 'stang came from the factory with SFI, however the built in distributor mounted indexed camshaft position sensor has only 8 teeth. Unfortunately that does not provide sufficient timing accuracy for my end application. There are only 8 teeth, even worse they are spinning at half the speed of the crank. It does, however provide indexing of which cycle the engine is on, and I will use the stock unit for that. By the way, for anyone else working with Ford distributor TFI cam sensors, here is the pinout (Looking at the word "Motorcraft" with the connector on your right): TOP 1: PIP signal output 2: 3: 4: +12 volts 5: BOTTOM 6: GND - -Jeff ------------------------------ From: Darrell Norquay Date: Mon, 29 Jul 96 21:30 PDT Subject: Re:toothed wheels for crankshaft position sensing At 04:15 PM 7/29/96 PDT, Matthew Lamari wrote: >I don't know where my colleague got his hands on this sensor (magnetic) but >are they available? There are lots of magnetic, proximity, etc. sensors available, for all different types of applications. Just have to know where to look. If this was not a rhetorical question, mail me back, I can come up with a list of sources. >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. regards dn dnorquay@xxx.com ------------------------------ From: John Dammeyer Date: Mon, 29 Jul 96 21:56 PDT Subject: Proper Mixture. 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: "Hans Hintermaier" Date: Tue, 30 Jul 1996 08:45:41 MET Subject: Color Tune John Dammeyer wrote: