DIY_EFI Digest Friday, 11 October 1996 Volume 01 : Number 308 In this issue: Re[2]: Using pc parts Air flow meter modification Re: Re[2]: Using pc parts Re: Air flow meter modification Re: Ignition timing reference points Re: ignition reference Re: Ignition timing ref points Re: Air Flow Meter Modification Re: Re[2]: Using pc parts Re: ignition reference Signoff Which TBI system to use? Re: Which TBI system to use? Re[4]: Using pc parts Re: ignition reference RE: Which TBI system to use? Re: Signoff Re: Air Flow Meter Modification Re: drive-by-wire Re: Using pc parts PC efi Re: ignition reference See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Terry Sare Date: 10 Oct 96 08:57 CDT Subject: Re[2]: Using pc parts Actually, W95 or Windows 3.1 is your cheapest method of graphics for a PC. While the reliability is somewhat suspect in that environment, it is actually the easiest to write for using commercial graphics library. Combine that with Visual Basic and you don't have to learn Windows programming either. Yes, I know Windows s--ks but its cheap. Yes, you also need a laptop style HD shock mounted to run it. Now if you don't mind rolling your own code, there are several libraries that do graphics under DOS. You just have to write all the code -- typically in 'C'. Everybody has jumped on the Windows bandwagon so I don't have to many references available at work. This is small extract from Embedded Systems Programming Aug. Issue Gigasoft 817-431-8470 graphics McRae Software 216-543-9242 GUI Ted Gruber Software 702-735-1980 Graphics. Another reference you can look in C User Journal. They have lots of ads for libraries. Of course if you have $$ QNX Photon GUI for QNX is verry nice -- so is QNX for process control. I have been playing with it in the lab and it has some nice features. Labview is easier but also pricy and windows based. My 2 cents on PC usage. Engine control is iffy but they make great display machines for your dashboard. They also can be used as dataloggers, etc. and network control for various systems used in the car. At one time I was looking at using a PC for the dashboard and distributed processing using Arcnet for communications link in my 68 Firebird. I don't understand EFI and engines well enough to do it so it got dropped. This list has been very educational!!!! TS ______________________________ Reply Separator _________________________________ On Wed, 9 Oct 1996, George M. Dailey wrote: [mucho snippage] > So, what's available for those fancy graphical interfaces in a PC controlled > i/o system? I was planning to use LabView (cost mucho dollars... but check out the alliance discount). Has one of the easiest to use interfaces out there... Not only that, but is really nifty as a programmming method. Drawbacks: 1. For big things, you need BIG computer. (Runse under Windows) 2. Cost.. $2K. But for a $100 alliance membership, you get 40% off (I think). Thor Johnson johnsont@xxx.edu http://falcon.mercer.peachnet.edu/~johnsont Have you seen the WarpMap lately? http://falcon.mercer.peachnet.edu/~johnsont/warpmap ------------------------------ From: "Bosch, AN, Andrew, Dr" Date: Thu, 10 Oct 1996 10:55:11 UTC-2 Subject: Air flow meter modification Hi all Maybe someone can help. Firstly, I'm probably going to reveal my lack of understanding by asking this queation, but here goes: The L-Jetronic has a flapper type air flow meter. If one measures the resistance along the graphite? track, it seems to change as you move a meter along the track in no seemingly logical way i.e the reading increases, then decreases, then increases again, etc Thats one question. The next is that I was wondering why the following shouldn't work: remove the A/F meter and remove the board with the sweeper. Then connect the board and sweeper dirctly to the shaft of the throttle body. As the throttle opens, there will now be a direct drive to the old A/F meter "mechanism". Only problem that I can think of is that the relationship between the amount of opening of the throttle and the movement generated at the "old" A/F meter mechanism will not be the same as in the "normal" set-up. So I figured that some sort of gearing system could be built in, so that eg when the throttle is half open, the A/F meter mechanism is fully across its sweep. I thought of doing this electronically, but then came up with the problem presented at the start of this post, namely that there does not seem to be a linear change in resistance in the A/F meter mechanism. The reason for all this, of course, is to try and do away with the very restrictive A/F meter. Can anyone help, please? Thanks in advance. Andrew Dr A. N. Bosch Physiology Department/ Sports Science Institute University of Cape Town Medical School P. O. Box 115 Newlands 7700 South Africa ------------------------------ From: Daniel Ridge Date: Thu, 10 Oct 1996 12:04:52 -0400 (EDT) Subject: Re: Re[2]: Using pc parts > Actually, W95 or Windows 3.1 is your cheapest method of graphics for a > PC. Actually, Linux is just about the cheapest way. Good tools, too. You could program SVGA directly via a lib or use the tk entensions to many scripting languages and run an X server in your car. If X is good enough for the Boeing 777, it's good enough for my car! :) > Yes, you also need a laptop style HD shock mounted to run it. In the linux groups there is currently a series of discussions about making linux ROMable. > car. At one time I was looking at using a PC for the dashboard and > distributed processing using Arcnet for communications link in my 68 > Firebird. I don't understand EFI and engines well enough to do it so > it got dropped. This list has been very educational!!!! So here's a thing. I remember one of those irritating Infiniti commericals about a year ago when the the Infiniti poster boy was talking about an in-car lan. I know nothing about it. Does anyone? Is there something we can salvage from it? What was on it? Are the transcievers cheap? Thanks, Dan ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\___/~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Daniel Ridge | USRA CESDIS Research Minion, Beowulf Project | Code 930.5 email: newt@xxx. W274 tel: 301-286-3062 | Goddard Space Flight Center fax: 301-286-1777 | Greenbelt, MD. 20771 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\_|_/~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ http://cesdis.gsfc.nasa.gov/people/newt ------------------------------ From: Todd Knighton Date: Thu, 10 Oct 1996 09:36:59 -0700 Subject: Re: Air flow meter modification Andrew, Good try but won't work. Take this example, at closed throttle and idle the engine flows x-cfm vs Wide Open Throttle (WOT) at idle or 1000 rpm flows y-cfm. Both these flows are very low due to low rpm, you can calc it out for engine displacement and rpm's to find your exact numbers. Now take the same two conditions at 7000 rpm's. Closed throttle is still a fairly low number, albeit about 7 times idle speed and WOT produces again approximately 7 times the WOT number at idle. So if you used the original code and got the thing wide open at 1000 rpm's the engine would flood, and become linearly leaner with an increase in rpm's. A hot wire with approximately the same flow curve would be a much better way to replace the AFM with little to no restriction. You could send your AFM to Best Products and have them try to calibrate a Ford hot wire to match the curve of your current AFM, then you would just have to replace the Inlet air temp sender with some sort of variable resistor that you could fine tune the air fuel ratio with. Hot wires don't need the inlet air temp because they read mass not cfm and don't need the correction factor. Godd Luck Todd Knighton Protomotive Engineering Bosch, AN, Andrew, Dr wrote: > > The L-Jetronic has a flapper type air flow meter. If one measures the > resistance along the graphite? track, it seems to change as you move > a meter along the track in no seemingly logical way i.e the reading > increases, then decreases, then increases again, etc Thats one > question. The next is that I was wondering why the following > shouldn't work: remove the A/F meter and remove the board with the > sweeper. Then connect the board and sweeper dirctly to the shaft of > the throttle body. As the throttle opens, there will now be a direct > drive to the old A/F meter "mechanism". Only problem that I can think > of is that the relationship between the amount of opening of the > throttle and the movement generated at the "old" A/F meter mechanism > will not be the same as in the "normal" set-up. So I figured that some > sort of gearing system could be built in, so that eg when the > throttle is half open, the A/F meter mechanism is fully across its > sweep. I thought of doing this electronically, but then came up with > the problem presented at the start of this post, namely that there > does not seem to be a linear change in resistance in the A/F meter > mechanism. The reason for all this, of course, is to try and do away > with the very restrictive A/F meter. ------------------------------ From: Kalle Pihlajasaari Date: Thu, 10 Oct 1996 11:07:13 +0200 (sat) Subject: Re: Ignition timing reference points Hi SMD, > Even the 'sealed' optical encoders can have problems. One is on the end > of an induction motor (for electric vehicles) and microscopic drops of oil > can get in cause false edges. A REAL pain. We just have not had good > experiences w/ them. I think this would be a problem with glass disk encoders, with just 360 lines you could get the unit in a perforated disk so the oil would not be a problem I think. I must make enquiries again, been a while. Cheers > Some one said they are analog in nature (agreed) so he couldnt use them w/ a > micro (here's where I disagree). We use an Analog devices R2D converter > (resolver to digital) that gives you a nice 10-14 bit word (depending on > dynamic perf. required) giving absolute poistion. Not too bad -> 0.35 to > 0.02 degrees resolution. (The R2D we use is about $60) Yeah, they would work quite well. The conversion has the problem that you have to sample it and at those resolutions you will have missing codes unless you sample real fast so you will be expending processor time unless you have a parallel external magnitude comparator. Nice thing though is the environmentally immune nature of the beasts. Cheers - -- Kalle Pihlajasaari kalle@xxx.za Interface Products Box 15775, Doornfontein, 2028, South Africa +27 (11) 402-7750 Fax: +27 (11) 402-7751 ------------------------------ From: Kalle Pihlajasaari Date: Thu, 10 Oct 1996 10:31:35 +0200 (sat) Subject: Re: ignition reference Hi Tom, > >We were going to make soft copper head gaskets for high compression > >conversions for older off-beat engines that there are no kits for > >by using sign writing vinyl which can be cut to 0.25 mm accuracy > >without any trouble. We have a set of vinyl masks which would > >be about right for a chainsaw but have not had time to try out the > >setup. With copper it is easier, you take some ferric chloride > >and sulphuric acid and then REVERSE electroplate the holes into the > >sheet with the vinyl mask protecting the gasket. > > Whoa, dude. My experience etching thick stuff is not happy. Also, > what's this with the sulfuric and ferric chloride? Ferric chloride > or ammonium persulfate are normal for etching PCB's. Can also use > alkaline ammonia and chromic-sulfuric acid, but they are dangerous. > Just plain nitric acid can also be used. But, as I said, the most > commonly used for PCB's are ferric chloride and ammonium persulfate. > If anyone cares, I can elaborate on pros and cons of each. Don't > have much success with anything very thick (that requires spraying > the etching solution to lessen 'undercut'). The sulphuric is just to add a bit of bite to the etchant. You will often find it used by normal FC etch people. The thick material undercut problem we would minimise slightly by the use of the electrical help which speeds the process up and allows you to keep the time short enough to actively monitor (read eye ball) stop etching as soon as you are ready. We were planning on 0.2 mm to 0.5 mm copper or brass shim. Cheers - -- Kalle Pihlajasaari kalle@xxx.za Interface Products Box 15775, Doornfontein, 2028, South Africa +27 (11) 402-7750 Fax: +27 (11) 402-7751 ------------------------------ From: Kalle Pihlajasaari Date: Thu, 10 Oct 1996 11:01:13 +0200 (sat) Subject: Re: Ignition timing ref points Hi Todd, > I want to do the timing with no interpolation so that the counter > can be very dumb and just count pulses ant any RPM and then go blip. >>> > > Good point; but I think you may find that a ref mark of say 50 deg BTDC for > each cylinder combined with a *simple* interpolation will do the job within a > few degrees as well, plus drastically reducing the interrupt overhead. But > let's see, I guess after every firing event you could determine the current >rpm and load; consult a lookup table for the correct "tooth count" of the next > fire event and initialize the count; when the count is up again it's "Fire in >the hold! <*ka-boom*>" time, plus set up the count for the next event. FYI the >spark map in one of the GM PROM's only has a granularity of 400 rpm increments > (Y axis) (if memory serves) vs a load (X axis) granularity of something like >12 or 16 or so columns. But what about dwell time for your coil(s)? Kalle, can > you discuss any of your plans for this with the list? I can discuss anything that people are prepared to listen to :-) In the limiting factor I would have 4 coils but My friend with the big V8 Mercedes block says a quality V8 ignition system will always have enough dwell for a 4 cylinder system. I will try with a single coil first. My ideal sollution was to have a optical setup that would generate 5 outputs, one a pulse train at say 1deg per pulse and the other 4 are earliest timing marks for each of the individual plugs which would then allow for real simple stuff that cannot go wrong and would fire on the second plug when you crank. For dwell in the 4 (or 2 coil wasted spark) system I could easily turn on the next coil as I fire the current one. This would give 90 deg dwell which would be loads of time but a bit crude and not constant with RPM. With a single coil I would have the option of adjusting dwell but I think that after TDC the spark can be quenched anyway even if it is still on. This would give a dwell of 90 deg minus timing angle which could be 70 deg that would suit me. Could start to use a timed dwell but this would them be a variable number of degrees before the firing point depending on RPM. If I put in real high performance stuff and don't want the coil to melt I could d othis and have a constant dwell time. The thought of putting a current transducer onto the coil supply to monitor the build up would also be an idea to evaluate the dwell angle for the next plog so I dont have to worry about time, just track the required saturation point for the coil on a spark by spark basis, could then use a 6 V coil with no ballast to get real short dwell times at high speed but on a 4 cyl this is all over kill. Cheers - -- Kalle Pihlajasaari kalle@xxx.za Interface Products Box 15775, Doornfontein, 2028, South Africa +27 (11) 402-7750 Fax: +27 (11) 402-7751 ------------------------------ From: "Terry McLane 312.630.0533" Date: Thu, 10 Oct 1996 12:32:32 CDT Subject: Re: Air Flow Meter Modification The L-Jetronic transmits a "wave" pattern, as the air opens. Interestingly enough, if you look at the specs for a particular car, (All-Trac Turbo for example), it says when the air meter is closed, resistance should be 400-600 ohms. When wide open it should be 20-2000 ohms! There are (as I remember) about 8 different gradations in the meter, with a linear resistance in between. Supposedly, each gradation is a fixed multiplier of air (logarithmic) like step 2 is 3 times more air than step 1, and step 3 is 3 times more than step 2, etc. I have also looked at replacing the velocity meter on my car, but it's rather difficult. I can get a VPC from HKS, which switches the car over to speed density, but it costs about $1000 US. If you were to wire the meter to the throttle body, (assuming you keep the thermistor in the intake air stream), you would be forcing a linear relationship between air flow and throttle body opening. This would probably cause some bogs and surges, and wouldn't work at all with a turbocharged vehicle. A somewhat better solution might be to hook up a vacuum pot to the intake manifold, and use the engine vacuum to move the wiper. By using different spring rates in the can (look at an old vacuum secondary carburetor or distributor advance unit) you could move the flapper door. This would be a sort of mechanical speed density system. It would also build in a little bit of lag, which the computer would expect. If you're more ambitious, you could always build a circuit using one of the non-restrictive Hitachi MAF sensors, use a Pic16 or 68HC11 and a D/A converter to map the MAF output to the meter output, build a table and then send it to the computer. Since the MAF already adjusts for temp, you could then use a potentiometer on the thermistor leads, giving the ability to tune the entire fuel curve by making the ECU think the air is colder (richer) or warmer (leaner). If anyone has any other solutions, I'd like to hear them as well. Terry ------------------------------ From: "Dan J. Declerck" Date: Thu, 10 Oct 1996 12:53:07 -0500 (CDT) Subject: Re: Re[2]: Using pc parts > > > So here's a thing. I remember one of those irritating Infiniti commericals > about a year ago when the the Infiniti poster boy was talking about an > in-car lan. I know nothing about it. Does anyone? Is there something we > can salvage from it? What was on it? Are the transcievers cheap? > > Thanks, > Dan There's a number of people whom make these car Lan transceivers. The CAN bus is primarily used by BMW, I think they get their parts from Seimens but I am not sure. I (squared)C is another bus type. I am not sure who uses this. The point is: there is NO standard for automotive communication busses. If automakers could get together and create a standard bus, the price of the parts would come down due to economy of scale. SAE ought to start a standards process to get the ball rolling. In telecom we do this all the time. - -Dan - -- => Dan DeClerck | EMAIL: declrckd@xxx.com <= => Motorola Cellular CSD | <= =>"The truth to CDMA... is spreading" | Phone: (847) 632-4596 <= - ---------------------------------------------------------------------------- ------------------------------ From: "Brian Warburton, c/o Turbo Systems Ltd" Date: Thu, 10 Oct 1996 19:31:34 Subject: Re: ignition reference >But, back to the problem, you can easily get a laser cut wheel made of steel >(or plastic) that can be made to your fancy. The cost will be < $50.00 QTY >1. All you need is a DXF file from your CAD program, and you have it, dosent >matter what shape or size. > >Sandy Two quick points here, firstly I'm pretty certain that a VRS sensor won't trigger with a plastic wheel, it must be made of steel. Secondly, you may find that the type of wheel that will interface sucessfully with any given ECU in terms of teeth thickness, teeth size, inter-teeth gap and mark-space ratio, is a function of the VRS input circuitry in that ECU. For example, if the teeth are too close together you may fail to detect a good clear zero crossing at high RPM. In essence, I'd be very surprised if it didn't matter what shape and size the wheel is. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Brian Warburton, "Still searching for the perfect curve....." email: bwarb@xxx.net Advanced Automotive Electronics Ltd, Van-Nuys House, Scotlands Drive, Farnham Common, England. SL2-3ES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ------------------------------ From: Joel Amundson Date: Thu, 10 Oct 1996 12:43:40 -0700 (PDT) Subject: Signoff Can smeone help me figre out how to signoff this list? An help would be much appreciated! ------------------------------ From: "Peter Orban" Date: Thu, 10 Oct 1996 15:50:59 -0400 Subject: Which TBI system to use? > From: cloud@xxx.edu (tom cloud) > Date: Wed, 9 Oct 1996 07:49:21 -0500 > Subject: Re: Using pc parts > ... > > That's why, in another post on a diff. thread (I think), I asked for > discussion about modifying OEM EFI controllers. Seems like that may > be the most efficient, quickest, satisfying way to go. I am also thinking about putting an EFI system on one of my older cars. It is a carburated Renault 18. I would think that a TBI system would be the easiest to adapt (for port injection I would need the hemi head from an 18i). I am also more familiar with Motorola microcontrollers. So what car should I scavenge at a junk yard, with about same size engine (1.7L), TBI, and Motorola based controller? Thanks, Peter - -- - -- Peter E. Orban National Research Council of Canada e-mail: peter.orban@xxx.ca ------------------------------ From: Mark Reichert Date: Thu, 10 Oct 1996 16:13:21 -0400 Subject: Re: Which TBI system to use? Hi Peter, > I am also thinking about putting an EFI system on one of my older > cars. It is a carburated Renault 18. If the engine is an 843 (crossflow head, 1.6L). Then you should be able to find the parts for a Bosch L-Jet injection system. These were available on some R18's. Also, some other cars with very similar systems would be the R17 and Fuego. The R-17 setup doesn't use an oxygen sensor. I've put one of these on a renault engine in my Lotus Europa. I think of it as a good testbed for future DIY improvements - all the pieces are there, and they just bolt right up (well, you might have to tap a fitting for a temperature sensor). If I can be of any help, feel free to ask. Mark Reichert markr@xxx.com ------------------------------ From: Terry Sare Date: 10 Oct 96 15:05 CDT Subject: Re[4]: Using pc parts Actually, there are some standards being worked upon. The SAE does have class of vehicle-multiplexing system, A, B, and C. Class D is being worked on. I don't know a lot about any of this but CAN is Class C and J1850 is Class B. This is from article in Circuit Celler April 96 on Vehicular Control Multiplexing. Combine the two and you get something complex. Motorola has some chips for this also. Arcnet is a 2.5 Mbit/s hardware link used primarly in factories now. It was one of the first PC networks, etc. before being replaced by Ethernet. SMC makes an 8051 with a built in ARcnet controller and they also make a stand alone controller. They have modified the spec to 5 Mbit/sec. The avantage to Arcnet is that the packet times are determistic AND the protocal is handled in hardware. Other than mapping the network, you get an intruppt if the message is for you, otherwise your micro never knew about it. Uses RS485 for a link. Nice and simple for embedded micros. TS - ----- > > > So here's a thing. I remember one of those irritating Infiniti commericals > about a year ago when the the Infiniti poster boy was talking about an > in-car lan. I know nothing about it. Does anyone? Is there something we > can salvage from it? What was on it? Are the transcievers cheap? > > Thanks, > Dan There's a number of people whom make these car Lan transceivers. The CAN bus is primarily used by BMW, I think they get their parts from Seimens but I am not sure. I (squared)C is another bus type. I am not sure who uses this. The point is: there is NO standard for automotive communication busses. If automakers could get together and create a standard bus, the price of the parts would come down due to economy of scale. SAE ought to start a standards process to get the ball rolling. In telecom we do this all the time. - -Dan - -- => Dan DeClerck | EMAIL: declrckd@xxx.com <=> Mo torola Cellular CSD | <=>"The tru th to CDMA... is spreading" | Phone: (847) 632-4596 <--------------- - ------------------------------------------------------------- ------------------------------ From: Gordon Couger Date: Thu, 10 Oct 1996 16:59:30 -0500 Subject: Re: ignition reference >From a previous life in the printing industry I recall that the undercut cut etching processes was countered with dragon's blood. Resin if I recall correctly. Any text on etching from the first half of the century should address this. In fact I think the problem is addressed as early as the 17th century by artist. Good luck Gordon > >> >We were going to make soft copper head gaskets for high compression >> >conversions for older off-beat engines that there are no kits for >> >by using sign writing vinyl which can be cut to 0.25 mm accuracy >> >without any trouble. We have a set of vinyl masks which would >> >be about right for a chainsaw but have not had time to try out the >> >setup. With copper it is easier, you take some ferric chloride >> >and sulphuric acid and then REVERSE electroplate the holes into the >> >sheet with the vinyl mask protecting the gasket. >> >> If anyone cares, I can elaborate on pros and cons of each. Don't >> have much success with anything very thick (that requires spraying >> the etching solution to lessen 'undercut'). > Gordon Couger Senior Software Specialist Biosystems & Agricultural Engineering Dept. Oklahoma State Univ. 114 Ag Hall Stillwater, OK 74075 gcouger@xxx.edu ------------------------------ From: "Orin Harding" Date: Fri, 11 Oct 96 00:23:38 UT Subject: RE: Which TBI system to use? Peter, I've tried both Ford and GM throttle bodies on my MGB EFI project and while both work ok I like the Ford one because of it's "packaging". It was easier to mount, connect air filter ducting to, etc. The GM one is like an old carb. with an injector stuck in it. When selecting one forget about engine displacement, think about the HP you assume your engine will produce with EFI. Find an engine that produces about the same HP and use that throttle body. As an example, the MGB's engine is 1.8L and I'm using a throttle body off a 2.5L engine. The Ford 2.5L only produced about 88 HP and the MGB can produce 100+. I've been able to use the smaller injector by increasing the fuel pressure from the factory 15.5 PSIG to 20 PSIG. Not the best solution but it works. Good luck..Orin - ---------- From: owner-diy_efi@xxx.edu on behalf of Peter Orban Sent: Thursday, October 10, 1996 3:50 PM To: diy_efi@xxx.edu Subject: Which TBI system to use? > From: cloud@xxx.edu (tom cloud) > Date: Wed, 9 Oct 1996 07:49:21 -0500 > Subject: Re: Using pc parts > ... > > That's why, in another post on a diff. thread (I think), I asked for > discussion about modifying OEM EFI controllers. Seems like that may > be the most efficient, quickest, satisfying way to go. I am also thinking about putting an EFI system on one of my older cars. It is a carburated Renault 18. I would think that a TBI system would be the easiest to adapt (for port injection I would need the hemi head from an 18i). I am also more familiar with Motorola microcontrollers. So what car should I scavenge at a junk yard, with about same size engine (1.7L), TBI, and Motorola based controller? Thanks, Peter - -- - -- Peter E. Orban National Research Council of Canada e-mail: peter.orban@xxx.ca ------------------------------ From: derek_deeter@xxx.COM (Derek Deeter) Date: Thu, 10 Oct 1996 18:15:00 -0700 Subject: Re: Signoff > Can smeone help me figre out how to signoff this list? > An help would be much appreciated! > Just in case you hadn't gotten this already: ==================================================================== >From owner-diy_efi-outgoing@xxx.edu Sun Sep 1 03:15:03 1996 Date: Sun, 1 Sep 1996 06:10:07 -0400 From: jsg@xxx.edu (John S Gwynne) Subject: [admin] List services (automated monthly post) This message is post monthly as a reminder of the available list services. For help: Send "help" to Majordomo@xxx. To post: Send to "[list name]@xxx.edu" To subscribe: Send to Majordomo@xxx.edu subscribe [list name] [your email address *only* if different than your "From" address] To unsubscribe: Send to Majordomo@xxx.edu unsubscribe [list name] [your *registered* email address if different than your "From" address] The archive to each mailing list is available through the following sources: 1) WWW. http://efi332.eng.ohio-state.edu/ 2) ftp. ftp://efi332.eng.ohio-state.edu/ 3) Majordomo. Send "index [list name]" to Majordomo@xxx. You will find a file "archive_date_index" whose contents show the period covered by each of the archive files "archive_num_*". Digest mode is available for each mailing list. Send "lists" to Majordomo for a listing a mailing lists served. To switch to the digest mode, unsubscribe from the regular list and then subscribe to the digest version (i.e., diy_efi-digest). WWW sites: archive http://efi332.eng.ohio-state.edu/ diy_efi http://www.cpsc.ucalgary.ca/~fridman/diy_efi efi332 http://www.iris.swin.edu.au/~aden/efi332/ Other related sites: http://devserve.cebaf.gov/~bowling/ http://spbted.gtri.gatech.edu:80/hpe/hpe.html Please send information to be added to this posting to jsg@xxx. John =========================================================================== - -- Derek Deeter derek_deeter@xxx.com Mentor Graphics Corp. (503) 685-7916 8005 S.W. Boeckman Rd., Wilsonville, OR 97070-7777 ------------------------------ From: "Jeffrey Engel" Date: Thu, 10 Oct 1996 20:04:46 +600 Subject: Re: Air Flow Meter Modification There was an earlier discussion along the lines of AFM vs MAF. At the time I was interested in replacing my AFM with a MAF unit. To replace the AFM with a MAF would involve absolute air pressure, temperature and velocity. Since the BAP and air temp sensor are there anyway, you should be able to use them as inputs along with the MAF to output an AFM signal to the computer. Somewhere along the way I decided to put up with the AFM restriction, but if there is interest in making a convertor include me in. An alternative would be to reprogram the ECU to accept MAF values directly. However, I can't get the 8061/5 op-code description. . . > From: "Terry McLane 312.630.0533" > The L-Jetronic transmits a "wave" pattern, as the air opens. > Interestingly enough, if you look at the specs for a particular car, > (All-Trac Turbo for example), it says when the air meter is closed, > resistance should be 400-600 ohms. When wide open it should be 20-2000 > ohms! There are (as I remember) about 8 different gradations in the > meter, with a linear resistance in between. Supposedly, each gradation > is a fixed multiplier of air (logarithmic) like step 2 is 3 times more > air than step 1, and step 3 is 3 times more than step 2, etc. > > > If you're more ambitious, you could always build a circuit using one of > the non-restrictive Hitachi MAF sensors, use a Pic16 or 68HC11 and a > D/A converter to map the MAF output to the meter output, build a table > and then send it to the computer. Since the MAF already adjusts for > temp, you could then use a potentiometer on the thermistor leads, > giving the ability to tune the entire fuel curve by making the ECU > think the air is colder (richer) or warmer (leaner). > > If anyone has any other solutions, I'd like to hear them as well. > Terry ------------------------------ From: hoss karoly Date: Wed, 09 Oct 1996 09:29:40 +0200 Subject: Re: drive-by-wire dzorde@xxx.au wrote: > > Could you elaborate on this, it sounds like a brilliant idea, but how > does it interface to the original system ? and what is the original > system ? Does the pump operate a slave cylinder that operates the > release arm in the gearbox ? > > I can see the idea, but I can't picture how the pump connects to the > system and operates. > it's VERY simple (so even I can make it) :) the orig sys is a cable operated one so the cable is PULLED by the lever my cylinder PUSHES the release arm thus lowering the force on the cable it's not connected to the arm so if it's out of order everything worx fine the only problem I can see is the speed if it's fast it can start oscillating if it's slow the whole thing does nothing when really needed bye charley ------------------------------ From: pantera@xxx.com (David Doddek) Date: Thu, 10 Oct 1996 22:25:52 -0500 Subject: Re: Using pc parts much deletion >That's why, in another post on a diff. thread (I think), I asked for >discussion about modifying OEM EFI controllers. Seems like that may >be the most efficient, quickest, satisfying way to go. > > >Tom Cloud > > Modifying an oem controller would be easy with the opcode list, processor info and schematic. Do you happen to have that for any particular manufacture? If you do then I could give you some ideas on what to do. David J. Doddek |pantera@xxx.com Owner SGD Electronics & Development Engr for Caterpillar |h 309 685-7965 Formula SAE Team Sidewinder 94-95 |w 309 578-2931 89 T-bird SC, 69 Fairlane w/SGD EFI |fx 217 428-4686 74 Pantera w/Electromotive Tec-II Twin turbos and Nitros | Hey, If you are going to go fast, go REEEAAL FAST. | ------------------------------ From: pantera@xxx.com (David Doddek) Date: Thu, 10 Oct 1996 22:25:58 -0500 Subject: PC efi All of the talk about PC based efi systems is interesting. Buy a data acuisition card, $300, buy an industrial timing card or 2, $400, or build one $? + much time, get a whole pc with lcd monitor or a single board pc with an lcd monitor, >$500 and then program in whatever language you like, C,+,+, basic, fortran, pascall, forth, dbase, prolog, pearl, etc. Then you have to find a place to mount it and buy a power converter $100. Or you could just buy a controller board that uses a zilog, motorola, intel or whatever type of 8, 16 or 32 bit controller. The board will have a serial port, a keyboard port, a timing unit, analog and time inputs, memory, an lcd interface, be able to run high level languages, and run on a single supply. The size is about 6 by 4 inches and will cost less than $500. Or you could take the tight wad approach like I did and buy a single chip like an HC11 or 8051, a couple of cherry injector drivers, and start building. By using a micro that had everything built in, including enough EEPROM to write the program in and a stock ignition and magnetic distributor, I made a fuel control with ignition for about 100 samolies that is simple, reliable, and was quick enough to build that while the people on this list have been trying to decide what to do, I have been driving my car. Lets just pick something and start building. I would like to see some discussions about problems encountered when putting engines in gear with hot cams, problems at different temps, starting problems, and how these problems are solved. Lets have some efi systems running out there. EFI is fun on a car and a great thrill when the key is turned for the first time and the engine goes: err err err put put sputter sputter bang pop varoom ruddin rudding. Just a pennies worth, can't affort any more, I am an engineer. David J. Doddek |pantera@xxx.com Owner SGD Electronics & Development Engr for Caterpillar |h 309 685-7965 Formula SAE Team Sidewinder 94-95 |w 309 578-2931 89 T-bird SC, 69 Fairlane w/SGD EFI |fx 217 428-4686 74 Pantera w/Electromotive Tec-II Twin turbos and Nitros | Hey, If you are going to go fast, go REEEAAL FAST. | ------------------------------ From: pantera@xxx.com (David Doddek) Date: Thu, 10 Oct 1996 22:25:54 -0500 Subject: Re: ignition reference >All this talk of making/using an encoder, just use a steel wheel with a VR >pickup, like most everybody else is doing. If you like you could also use a >hall effect pickup. One thing again, is that if you are getting timing from >the distributer, it will be subjected to a bunch of error, many from chain >(belt) stretch, and other cam related jitter. Ask someone how their >electromotive distributer pickup works! (have has several bad stories) > >But, back to the problem, you can easily get a laser cut wheel made of steel >(or plastic) that can be made to your fancy. The cost will be < $50.00 QTY >1. All you need is a DXF file from your CAD program, and you have it, dosent >matter what shape or size. > >Sandy > > > Try this. Go to a machine parts store. Buy a gear for chain with the number of teeth that you want, ie 36. Take it to a local machine shop and have them cut off just a fraction of the teeth to make the ends flat and wa-la, a timing wheel with highly accurate spacing. Or of you want more teeth, then try a regular gear, but that may cost a little more. With a gear for small enough chain, you should be able to get even a 60 tooth gear. David J. Doddek |pantera@xxx.com Owner SGD Electronics & Development Engr for Caterpillar |h 309 685-7965 Formula SAE Team Sidewinder 94-95 |w 309 578-2931 89 T-bird SC, 69 Fairlane w/SGD EFI |fx 217 428-4686 74 Pantera w/Electromotive Tec-II Twin turbos and Nitros | Hey, If you are going to go fast, go REEEAAL FAST. | ------------------------------ End of DIY_EFI Digest V1 #308 ***************************** 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".