DIY_EFI Digest Monday, 22 January 1996 Volume 01 : Number 018 In this issue: Re: Digital Distributorless Ignition System Re: Digital Distributorless Ignition System Re: Engine Reversal and EFI Engine codes for '84 T/A Help Please!!! Re: Injectors and fuses Re: Injectors and fuses Re[2]: Engine Reversal and EFI Re: Engine codes for '84 T/A SHAMELESS EFI332 PROMOTION - was Re: ECUs Re: O2 Sensor type? previous mis-post Re: PC Based EFI See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: sian@xxx.uk (RAGHBIR SIAN) Date: Sun, 21 Jan 1996 12:57:07 GMT Subject: Re: Digital Distributorless Ignition System > >The Programmable, Digital Distributorless Ignition System is finished! Thank >God. Anyhow, all of you had expressed interest in the system sometime in the >past so I wanted to update you. > >The best way to get the articles is via my Web page at >http://spbted.gtri.gatech.edu/hpe. In the second article, I'm missing the two >equations and the table, but I hope to have them in by the time you get this >message. Also, more legible versions of the schematics will be made available >on my FTP site (same address, userid: anonymous). The DOS version of the PC >software will be place on the FTP site also. > >Please send me any comments and questions. I'm working on the 3-axis >accelerometer toy now. Let me know if you're interested. It will have a >128x128 graphic LCD in a handheld device. The accelerometers are attached to >an unsprung (hopefully close to the roll center) point on the car and a cable >will plug into the unit. Should record about a half-hour of data - great for >autocrossing. > >-tim drury > Tim .. YES YES YES ... I'm interested .. will I be able to use this setup as > a sort of "pocket dyno" for engine tuning ... I'm more concerned with linear > acceleration than the "friction circle" > > Jim Conforti > Tim.. I am interested too in the accelerometer but for the 'friction circle'. Keep me posted. Regarding the place where the sensor would go Tim you wrote: >>The accelerometers are attached to>an unsprung (hopefully close to the roll >>center) So what would you do when the roll centre of the vehicle concerned changes in relation to suspension movement.... Okay just kidding. Or may be place two of the units one at the front and one at the rear. I remember this was one of the places the formula one boys placed the sensors for high bandwidth active ride control. By the way what has happened to the article on your DDIS and your Web site. May be a slight technical glitch ya... Let me know when this site is fully operational. Regards R.S.Sian >>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<< Raghbir Sian Engine Control and Combustion Analyst "As Always A ***CONTROL*** Freak" A committee is a group of the unwilling, chosen from the unfit, to do the unnecessary.... Anonymous Life is just one damned thing after another... Joseph Heller Time spent on any item of the agenda will be in inverse proportion to the sum involved. E-mail: sian@xxx.uk >>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<< ------------------------------ From: george dailey Date: Sun, 21 Jan 1996 10:40:56 -0600 Subject: Re: Digital Distributorless Ignition System At 12:57 PM 1/21/96 GMT, you wrote: >> >>The Programmable, Digital Distributorless Ignition System is finished! Hey tim drury, I'm new to the group (and the net) but have considerable experience in retrofitting OEM EFI systems into ancient vehicles. Please tell me that you have a DDIS for small block chevys that's compatable with the exiesting CCC EST system. thanks GMD@xxx.com ------------------------------ From: Bill Lewis Date: Sun, 21 Jan 1996 12:44:47 -0500 Subject: Re: Engine Reversal and EFI Engines normally have the piston pin bores slightly offset toward the thrust side to reduce friction and piston slap. Running the engine the other direction will throw this all out of whack. Some engines also have oiling systems with the direction of rotation taken into account. For example, something spinning a certain direction slings oil off itself and onto something else to be lubricated. If I'm not mistaken, the 4.3 litre Chevy is a small block V8 chopped down. Often twin engine installations in boats run the engines in opposite directions, so you might look into SBC marine setups to see if a reverse direction engine is produced, and what they've done to support it. /Bill ------------------------------ From: ws6transam@xxx.net (Daniel R Burk) Date: Sun, 21 Jan 1996 12:55:23 -0500 Subject: Engine codes for '84 T/A Does anyone have the hexadecimal engine codes for the GM ALDL computers as used in '82 through '92? I have an '84 that I want to begin communicating with, but I do not know which addresses I need to poll to receive the engine diagnostics data. So far I have struck out in finding them via the random method. Also, the ALDL interface seems to have the pins in the wrong locations than the "official" designation. Here's what I mean: OFFICIAL: for the 12 pin ALDL port. Pin Function My Connector has these pins A Ground Pin A B ALDL Diagnostics B C C D D E 160 Baud data line F F G H 8192 Baud data line J K L M The connector pinout is arranged in this fashion: F E D C B A G H J K L M The communications protocol seems to be to pull the diagnostics line high, and send the hex command "F4" down the data line. (Your choice of baud rate.) You then release the diagnostics line and wait for your data. I base this information on old documents I found at work involving automotive data acquisition. Any help would be appreciated. - --- Dan. ------------------------------ From: "Jim Staff" Date: Sun, 21 Jan 1996 13:42:55 -0500 Subject: Help Please!!! Hello. I'm working on a system for super mileage vehicle competition, and I need to build an injection system. And I was wondering if I could get help from the people here at DIY_EFI. I'm an electronics guy and have no clue how this automotive specifics stuff works. So I'll give you a rundown on what I have to work with and if anyone could help me you could reply to DIY_EFI server or to m e personally at Staffj@xxx. Basics =============================================================================== = Engine : Briggs & stratton 3HP, 4 cycle single cylinder (Wow huh?) Intake : Carb. Ingition : Briggs & Stratton's Factory Points Ignition. Notes : Exactly the same engine you'll find in 90% of the lawn mowers in the world. It runs like a pig and is a massive gas hog. The compression ration as measures was Å8:1 and I know it runs really rich. Modification : I have a second PTO shaft that is infact the cam shaft. It provides a single RPM/Power cycle. That way I don't have to arbitrate the exhaust and power strokes. Advanced =============================================================================== = Modification 1--Tachometer. The Tachometer I'm going to use is as good as finished. I thought it was best to use a Hall Effect sensor as a pickup on the cam shaft. This is then put through a devide by 10 and a devide by 5 then it is inverted and fed as an interupt into my computer system. Modification 2--Electronic Ignition.(Or at least better ignition) Since I have to have a car battery on theis thing anyway, I want to replace the Briggs standard points ignition system. I'll replace it with a pickup coil system and a switching modual from an GM car and a ignition coil from a Ford. I think I'm trigger it with a hall sensor on the cam shaft just before the piston reaches TDC, I'll make the sensor movable so that you can adjust the spark advancement by hand. I thought alternatively I could have that sensor act as a sentinal and make the computer time it. But since I'm using a 286 PC I can only get hundreths of a second from the RTC. I was wondering if this is an OK amount of slack? Well anyway anything is a good replacement for the points system. Modification 3--EFI This is were I get completly lost. I know that injectors take Å+5V at a good chunk of amps. They run on a square wave duty cycle. I don't know how I could create this duty wave from my digital output. Since a bus cycle is a specific amount of time I can't hold the bus. And I have no clue how a real ECU does it. I could use a lot of help here. If there is any specific or general stuff you know I'd like to hear it. I do believe that on the market somewhere there has t o be an IC that turns an 8 bit binary number into a pulse width for the injector. Modification 4--Feedback for the EFI I need help in this area too. I know that an O2 sensor provides a voltage based on the amount of air present in the exhaust. I'm going to sample this wit h an analog to digital converter. Most of them are +1.2 V to +.1 V so my sources tell me. I haven't pinned down a MAF sensor yet but I believe that they are als o voltage analog signals, so I can do the same thing with this. If it's not could you please tell me what it really is and how to change it into some kind of voltage. The last thing I want to have is a temp sensor that way I can calculat e the true mass of the air going into the engine. Then I can solve the equation for x (amount of gas needed) and inject it. Mod 5--LCD display I want to use a standard 16x2 LCD line display and have it track RPM and MPG ------------------------------ From: dn Date: Sun, 21 Jan 96 13:29:49 MDT Subject: Re: Injectors and fuses > > Ah! but these injectors aren't connected directly accross 12V. > Manufacturers either use a current limiting resistor or peak and hold > drivers. > Yeah, I wasn't referring to what the driver may do to alter the current drive to the injector. That's a whole separate issue. I was assuming worst case where the driver is a dead short, having self destructed for whatever reason, thus applying battery directly to the injector. This is, after all, exactly what the fuse is for in the first place, to protect the wiring harness and, if you're lucky, the injector itself from some catastrophic failure elsewhere in the system. regards, dn - -- ------------------------------------------------------------------------- Darrell A. Norquay Internet: dn@xxx.ca Datalog Technology Inc. Bang: calgary!debug!dlogtech!darrell Calgary, Alberta, Canada Voice: +1 (403) 243-2220 Fax: +1 (403) 243-2872 @ + < __/ "Ain't no substitute for clock speed or compression ratio" ------------------------------------------------------------------------- ------------------------------ From: dn Date: Sun, 21 Jan 96 13:15:59 MDT Subject: Re: Injectors and fuses > No auto manufacturer is going to bury a fusible link in the wiring anywhere > which will totally disable the car and cannot be replaced! > I totally disagree with your above statement, 'cause I have had to replace, on several occasions, fusible links (alternator output and main power feed to the fuse panel come to mind) which are completely buried deep in the wiring harness in some inaccesible location, and without which the car would not run at all. > No fuses in the injector feeds. CPU maybe, but not injectors. I have yet to see any automobile which doesn't have fuses in ALL main power feeds throughout the electrical system. As was pointed out by another reply to this thread, the fuses are there to protect the vehicle's wiring, not whatever is connected to that wiring. Fusible links are usually used for high current feeds (say, alternator output) where it is impractical (read too expensive) to put in an 80A fuse. Note that in my original message I said "MAY BE used". In order to keep wiring complexity down, and thus the number of fuses required, auto manufacturers may group several systems together on the same power feed. Thus any given fuse in the panel may be labelled, say, "AUX", but may feed injectors, fuel pump, and cigarrette lighter from this circuit. It may not be OBVIOUS that the injector drivers are fused, but they are. regards, dn - -- ------------------------------------------------------------------------- Darrell A. Norquay Internet: dn@xxx.ca Datalog Technology Inc. Bang: calgary!debug!dlogtech!darrell Calgary, Alberta, Canada Voice: +1 (403) 243-2220 Fax: +1 (403) 243-2872 @ + < __/ "Ain't no substitute for clock speed or compression ratio" ------------------------------------------------------------------------- ------------------------------ From: dzorde@xxx.au Date: Mon, 22 Jan 96 08:57:01 Subject: Re[2]: Engine Reversal and EFI We run a Fiat 850 sport with a 127 engine, this also runs the wrong way. We could get away with just turning the pistons around on the rods and get the cam ground for the other way. This will now run at 9000 rpm all day. Dan dzorde@xxx.au ______________________________ Reply Separator _________________________________ Subject: Re: Engine Reversal and EFI Author: diy_efi@xxx.edu at INTERNET Date: 22/1/96 8:35 AM Engines normally have the piston pin bores slightly offset toward the thrust side to reduce friction and piston slap. Running the engine the other direction will throw this all out of whack. Some engines also have oiling systems with the direction of rotation taken into account. For example, something spinning a certain direction slings oil off itself and onto something else to be lubricated. If I'm not mistaken, the 4.3 litre Chevy is a small block V8 chopped down. Often twin engine installations in boats run the engines in opposite directions, so you might look into SBC marine setups to see if a reverse direction engine is produced, and what they've done to support it. /Bill ------------------------------ From: FIScot@xxx.com Date: Sun, 21 Jan 1996 20:40:54 -0500 Subject: Re: Engine codes for '84 T/A Subj: Engine codes for '84 T/A Date: 96-01-21 13:31:47 EST From: ws6transam@xxx.net (Daniel R Burk) > Does anyone have the hexadecimal engine codes for the GM ALDL computers > as used in '82 through '92? I have an '84 that I want to begin > communicating with, but I do not know which addresses I need to poll to > receive the engine diagnostics data. So far I have struck out in > finding them via the random method. Also, the ALDL interface seems to > have the pins in the wrong locations than the "official" designation. You have a slow ALDL box. It is 160 baud, and it only sends data, it does not receive. Sometimes GM did not have a separate ALDL data pin, and the data comes out on the CEL line. > Here's what I mean: OFFICIAL: for the 12 pin ALDL port. [deleted] > The connector pinout is arranged in this fashion: > F E D C B A > G H J K L M > The communications protocol seems to be to pull the diagnostics line > high, and send the hex command "F4" down the data line. (Your choice > of baud rate.) You then release the diagnostics line and wait for your > data. I base this information on old documents I found at work > involving automotive data acquisition. > Any help would be appreciated. Toss what you have been reading? That is incorrect as stated. It is part of the 8192 baud protocol to send something similar, but that has no application in your ECM. There is no easy way to reverse engineer this. One way is to get the code out of the ECM's ROM and disassemble it, and figure out what it is sending. Another is to learn all you can about what it is sending (get a factory manual) and use another scan tool and try to figure out what is what from the outside. Good luck, Scot Sealander FIScot@xxx.com ------------------------------ From: "Andrew Dennison" Date: Mon, 22 Jan 1996 15:34:28 EST+10 Subject: SHAMELESS EFI332 PROMOTION - was Re: ECUs On 19 Jan 96 at 12:33, Gavin Walker wrote: > My soldering skills are best not talked about in polite circles so > an ideal development platform would be one like. > > - ECU running a multitasking operating system > - Services available to access input and manipulate outputs > (like timing, etc). - Each service would have a local butter to > store/read data cyclicly so the optimization can be done > externally. - Persistent code/data storage such as FRAM chips. - > Laptop interface > > > So you'd have some, say Java, firmware on the FRAM and more bulky > code on the PC. Adding new drivers would create new Java objects to > manipulate them. > > Does anything close to this exist or is it all pipe dreams? > The EFI332 project is a step towards what your dreaming about - it uses a 32 bit processor and will use RTEMS - a real time multi tasking OS. The real time bits are controlled by a fancy timer system and there is FLASH memory and battery backed RAM, all you'd need to do is write the java firmware! Check out the EFI332 web page: http://www.cim.swin.edu.au/~aden/web-docs/efi332/332_index.html Andrew - ------------------------------------ Andrew Dennison - Research Associate IRIS - Industrial Research Institute - Swinburne University 545 Burwood Rd. Hawthorn Victoria 3122 Australia Phone: +61 3 9214 5033 Fax: +61 3 9214 5050 ------------------------------ From: robert dingli Date: Mon, 22 Jan 1996 16:46:01 +1100 (EST) Subject: Re: O2 Sensor type? Hi Mark, since this discussion is getting a little off the diy-efi track, I'm replying personally. > They used to be that price !!!! Perhaps there has been an upgrade?? The circuit is quite complicated. > I used the UEGO it on racing engines mainly. Tell me more.. > This engine of yours sounds interesting. Whats your BMEP and hows your NOX? The engine uses a novel Hydrogen Assited Jet Ignition (HAJI) ignition syetem which gives stable ignition out to extremely lean operating conditions. The HAJI injector fits into the spark plug hole and contains a direct injection hydrogen injector, a very small spark plug and a small prechamber. The hydrogen is only for ignition and only provides a tiny fraction of the input energy. The combustion occurs over a very short period, an order of magnitude less than conventional ignition. It may have applications in high speed racing engines (>20000 rpm). Back to your questions.. The BMEP is what you would expect at those operating conditions as apart from stable ignition, the system doesn't increase that energy output. At lambda 2, the NOx is around ambient and certainly at the lower limits of our ~$30000 NOx measuring apparatus. The system is currently being tested on a single cylinder optical CFR which has a see through piston crown for combustion analysis. We have also tested it on the same Lancia 16V 2 litre which I use for my control work. There are many more details on the HAJI www site. I don't know the address exactly, but you can find it by doing a net search on HAJI or even through the University of Melbourne, Mech Eng and then the Transport Energy Group. Robert > MRB Design PS what do MRB Deisgn do?? - -- - ---------------------------------------------------------------------- Robert Dingli r.dingli@xxx.au Power and Control Systems Thermodynamics Research Lab Electrical Engineering Mechanical Engineering (+613) 9344 7966 (+613) 9344 6728 University of Melbourne, Parkville, 3052, Victoria, AUSTRALIA - ---------------------------------------------------------------------- ------------------------------ From: robert dingli Date: Mon, 22 Jan 1996 17:17:00 +1100 (EST) Subject: previous mis-post Sorry about the previous post, I didn't intend to clutter the whole list with such a specific discussion. Of course, if anyone else is interested, please feel free to let me know. Robert Dingli - -- - ---------------------------------------------------------------------- Robert Dingli r.dingli@xxx.au Power and Control Systems Thermodynamics Research Lab Electrical Engineering Mechanical Engineering (+613) 9344 7966 (+613) 9344 6728 University of Melbourne, Parkville, 3052, Victoria, AUSTRALIA - ---------------------------------------------------------------------- ------------------------------ From: ALIPPER@xxx.com Date: Mon, 22 Jan 1996 01:28:19 -0500 Subject: Re: PC Based EFI Jim, I'm glad to see your interest in the PC-based EFI. You ask: > First. I looked at the way you decode the address >structure on the ISA bus, and how does that stop other >devices from addressing the injector. Since you only use >the first 5 address lines.... The addressing is making use of the CPU's I/O port addressing mode, NOT memory addressing. Port addressing only uses A0-A9. My design decodes A5-A9 as the address block in which the EFI will operate, then within that, it only uses A0-A4 for the locations it requires. (note the inclusion of the IOR and IOW signals in order to enable any of the devices). > Second. The circuit you use to drive the injector. Your >not drive the injector all by yourself are you? It looks >to me as though you're giving it to the cars ignition >system.. Could you clarify this. The injector may be operated in several modes (see the doc files). Ordinarily, it fires the injector(s) once every spark (as do virtually all TBI systems). In certain cicumstances (e.g. starting and rapid accelleration) this is not adequate. During these times, it may be switched to async mode where the injector fires off of on of the timer outputs at an adjustable interval. There is no need at all for interrupts in this design, thereby simplifying the implementation. As you can see, it can even be operated from BASIC. Hope this helps. - Al - ------------------------------ End of DIY_EFI Digest V1 #18 **************************** 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".