DIY_EFI Digest Monday, 14 October 1996 Volume 01 : Number 313 In this issue: Re: Ignition Project... or..."That dog don't hunt" Using GM Controllers Ford Knock Sensor and Spark Control Re: Thermocouple for EGT Re: Volume of fuel injected Re: Thermocouple for EGT Forwarded: Re: Air Flow Meter Modification re: L-Jet Re:Re: Thermocouple for EGT,Gm contollers Re Gm contollers See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: LotusM50@xxx.com Date: Sun, 13 Oct 1996 13:07:50 -0400 Subject: Re: Ignition Project... or..."That dog don't hunt" In a message dated 96-10-12 14:12:14 EDT, jma2@xxx.com (Jim Armstrong) writes: << And it's amazing how much more reliable those cute little cars become when you remove any part, with possible exception of lamps, having to do with Lucas and replace it with OEM Bosch or Delco. This includes all ignition including the ballast resistor which should be replaced with part & value designed for the Coil. >> Having a couple of British car, I can claim consideralbe experience with Lucas, Price of Darkness. What he says is quite correct. It is quite amazing how much better my Jensen runs with an MSD ignition (albeit using a late model (1990) Lucas (magnetically triggered) distributor, that does nothing but spin, with the timing controlled by a simple MSD timing "computer". I beleive that a Mallory distributor is available for the Spitfire combine that with a Accell 300+ ignition box and coil (or the MSD stuff) and I beleive you will be quite pleased with the difference. Of course, that won't be as much fun as doing the project you described. (On I secretly would like to do for the Jensen when I have the time - which i don't even have to finish my 1975 Lotus Elite Electromotive FI conversion). If all you want is efficiency and reliability, then go for the Mallory /Accell/MSD stuff, If you want a real challenge, your project sounds like a good, interesting one. I for one, will be intently listening to how it progresses. Cheers, Bonn ------------------------------ From: peter paul fenske Date: Sun, 13 Oct 1996 08:46:22 -0700 Subject: Using GM Controllers Hi FOLKS There have been some requests on using OEM controllers for FI. If you have a V8 perferably a chev normally aspirated the task is relatively easy. Order of things to do. Find a 730 Broadcast GM ECm. 87 up GM v6 to 92, 90-92 F body. Usually cost me 80$ canadian with harness and sensors. Buy a calpak for a 90-92 GM fbody # 16151348 Cost is 50$ canadian. You will have to build the VATS defeat with a 555. You need 30 hz, open collector op, 50% duty cycle( as close as you can get) Or save the eprom contents, change byte 0016H from 10 to 00 and change byte 8008 from 8D to AA. then reprogram , , this chip is a 27C256 ie 12.5 volts program. Use a 91 camaro wiring diagram to wire up using the J body harness. Also you need the sensors ie map, knock tps ect. On the tps you may have to rewire the plug. You dealer sells the camaro plug if you can't find one. You don't need the V6 coilpak. Just wire in a HEI module from a late model V8 application or use a gm distributer if possible. The hei module can be driven by any magnetic trigger, ford,chyrco,nissan ect. Block learn will adjust the fuel curve to stoich +- 10% this give a bit of tolerance. If you run out of block learn you can adjust the fuel pressure. If you need more idle speed you can adjust idle to 650 rpm. The computer controlled idle speed is 550. Unless the idle is at 150 rpm over set point there will be no error code set. This tsb fix tends to aleviate the oscillation in idle you get with a hotter engine. Anyways I can't give out fuel curves timing ect ect ect. Just too much flak my way. Anyways hope this helps: peter ------------------------------ From: mustang@xxx.edu (Jeff Webb) Date: Sun, 13 Oct 1996 15:16:55 -0400 Subject: Ford Knock Sensor and Spark Control I've noticed that there's been a lot of discussion about electronic ignition and spark control systems recently, so I thought some of you might be interested in my current project. I plan on designing an electronic spark control system for my '65 289 V8 Ford Mustang. My plan is to start out by simply monitoring engine parameters, and then work my way up to ignition control and electronic fuel injection. This summer, two of my friends and I designed an instrumentation system for my car that monitors manifold pressure, throttle position, air temp, engine temp, spark advance, spark dwell, and engine rpm. (I have info and calibration data on the Ford MAP, ECT, and ACT sensors if anyone is interested.) The system uses a 68HC11 to display the data in real time on an LCD display, or log the data to memory in a battery-backed SRAM for downloading to a PC. My next project is to interface a knock sensor to the system. From what I understand, Ford uses two types of knock sensors: one for smaller engines with knock frequencies of about 6 Khz, and one for larger 4.9L/5.0L engines that knock at about 9.5 Khz. The sensors put out a small voltage signal (about 1V) that changes with the frequency of engine vibration. (All of this info is from Ford Fuel Injection & Electronic Engine Control by Charles Probst.) I plan to sample the sensor signal with an A/D converter, and then analyze the data to figure out exactly how I can determine when engine knock occurs. Does anyone have any other information on these sensors? Is the output essentially a frequency to voltage converter, or is the signal a sine wave with a changing frequency, or is it a raw signal that requires extensive DSP? I have purchased a knock sensor for a 1990 Ford Bronco 5.0L for use on my Mustang. My first problem is mounting the sensor. I have no information on the stock mounting location for this sensor, or how critical the mounting location is. What other engine sounds might occur at the knock frequency? I would greatly appreciate any information on this subject. Thanks, Jeff Webb mustang@xxx.edu ------------------------------ From: dzorde@xxx.au Date: Mon, 14 Oct 96 08:16:16 Subject: Re: Thermocouple for EGT Didn't someone mention that there is one mounted on the GM TPI EGR unit, or is that only a temperature activated switch ? Dan dzorde@xxx.au ______________________________ Reply Separator _________________________________ Subject: Thermocouple for EGT Author: diy_efi@xxx.edu at INTERNET Date: 10/11/96 8:19 PM I'm also interested in this, as are probably quite a few others on this list. Please would anyone replying to the above question also send it to the list and not just a private reply. Thanks. 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: pkb00523@xxx.edu (Len Hochendoner) Date: Sun, 13 Oct 1996 21:41:04 -0400 Subject: Re: Volume of fuel injected I'm very interested the design of the injector drive circuit. Does anyone have a design they would like to share? Has anyone seen the design Ed Lansinger had in his September 95 Circuit Cellar INK article? (i.e. TIP120 power Darlingtons) If so, what do you think about that? >At 07:03 PM 10/8/96 +0100, you wrote: >>>Here's my problem. I'm trying to calculate the volume per burst for a >>>typical fuel injector. I've downloaded some specifications, but I'm at >>>a loss to break them down. > > > Ok, here's my understanding of injectors - the flow rate (cc/min or >lb/min) is rated at 100% duty cycle. As for other duty cycles you need to >do a little testing, but it helps to understand how the injector works. > FI are little solenoids. When you first apply the voltage, it takes some >time to built up enough current (and magnetic feild -> force) to start the >valve opening. This is dead time and can be corrected for easily (add it to >the required 'on' time). The valve then starts to open and assume the flow >increases linearly until it is wide open (and has reached its 'rated' flow). >At this point you can reduce the voltage on the injector to save power and >off time - more on this later. You leave it on for some desired time at >rated flow - this is about the only linear part of the curve. When you go >to turn off the injector, you do something to try and stop the magnetic >field holding the valve open. Disconnect it. The problen is that the >injector is a coil of wire around magnetic stuff and has inducance so the >current (and the magnetic field) wont go to zero instantaneously (would take >infinite negative voltage). Dont know if your an EE, but there is this rule >that goes V=di/dt... Anyway, thats why you usually need some sort of clamp >to keep from killing your drive circuit. So, after some time delay the >magnetic field drops below that required to hold the valve open and the >valve starts to close (due to that little spring and maybe fuel pressure). >Again assume some linear curve (which I again doubt - but hey, these are >supposed to be negligible times right;) And finally the valve is closed. > So the things to acct for are: > 1) delay until beginning of turn on > 2) time required to turn on the injector (some fixed amt of fuel >will be squirted during this period. If you assume linear flow increase, >this amt is quadratically (or worse) related to this time.) > 3) actual time the FI delivers 'rated' flow > 4) delay from when you remove power until valve starts closing >(again some twisted relationship of flow vs time) > 5) the valve actually closes. > >At high duty cycles, period 3 should swamp all others and you can assume >'linear'. Time 1 is easy to figure out. See how small of an injector pulse >delivers NO flow (it never gets to open). The other times might be taken >into account (although I dont know of anyone who does this, but its >possible) if you plot flow vs. on time. This is probably only interesting >at very low flow rates. > > Hope this helps. If anything here is too complicated, just ask. We build >things that drive inductors and actuators all the time and sometimes I >confuse myself. If you want more detail, ask and Ill scare you w/ math;) >(albeit simple calculus) > >SMD > > > ------------------------------ From: peter paul fenske Date: Sun, 13 Oct 1996 18:36:17 -0700 Subject: Re: Thermocouple for EGT Sorry only a temp switch: Later: peter At 08:16 AM 10/14/96, you wrote: > > Didn't someone mention that there is one mounted on the GM TPI EGR > unit, or is that only a temperature activated switch ? > > Dan dzorde@xxx.au > > >______________________________ Reply Separator _________________________________ >Subject: Thermocouple for EGT >Author: diy_efi@xxx.edu at INTERNET >Date: 10/11/96 8:19 PM > > >I'm also interested in this, as are probably quite a few others on >this list. Please would anyone replying to the above question also >send it to the list and not just a private reply. > >Thanks. > >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: RABBITT_Andrew@xxx.au Date: Mon, 14 Oct 1996 11:51:32 est Subject: Forwarded: Re: Air Flow Meter Modification Most of the US EEC4 MAFs use a Hitachi bypass design. I know it's fitted to the 4-cyl Zetec - Mondeo/Contour, the 3.0L V6 from the previous Taurus, and (judging from photos in Probst), also the 5.0L Mustang. Probably still being used on most of the latest versions of all of these, but since I'm not in the US, I can't say for sure. Looking down-stream from the up-stream side of the meter, you will see two bores, one large one with nothing in it, a small one (the bypass) with the hotwire probe in it. The housing is an aluminium casting (or aluminum if it's made in the US) From: (Stephen Dubovsky) dubovsky@xxx.edu:smtp Date: ## 10/11/96 13:06 ## ... > 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 ... MAF - mass air flow? Like a hot wire sensor? If so, what are their part numbers? Am looking for a hot wire sensor. Was thinking of getting one from a junkyard (anyone know of a car that uses them?) and modifying it instead of going through the hassle of building one w/ precision thermistors/thermocouples. Tnx, SMD ------------------------------ From: RABBITT_Andrew@xxx.au Date: Mon, 14 Oct 1996 11:55:08 est Subject: re: L-Jet >hot-wire is the most accurate but also the most expensive (read >hi-tech), reverse for manifold pressure (MAP)) I disagree, Honda is using MAP for their ULEV Accord, and saying things like 'accurate A/F ratio control' in the same breath. ------------------------------ From: Jennifer Rose Date: Sun, 13 Oct 1996 21:59:18 -0700 Subject: Re:Re: Thermocouple for EGT,Gm contollers >From: dzorde@xxx.au >Date: Mon, 14 Oct 96 08:16:16 >To: diy_efi@xxx.edu >Subject: Re: Thermocouple for EGT >Sender: owner-diy_efi@xxx.edu >Reply-To: diy_efi@xxx.edu > > > Didn't someone mention that there is one mounted on the GM TPI EGR > unit, or is that only a temperature activated switch ? > > Dan dzorde@xxx.au > > >______________________________ Reply Separator _________________________________ >Subject: Thermocouple for EGT >Author: diy_efi@xxx.edu at INTERNET >Date: 10/11/96 8:19 PM > > >I'm also interested in this, as are probably quite a few others on >this list. Please would anyone replying to the above question also >send it to the list and not just a private reply. > >Thanks. > >Andrew >Dr A. N. Bosch >Physiology Department/ Sports Science Institute >University of Cape Town Medical School >P. O. Box 115 >Newlands 7700 >South Africa > Hate to give an answer and ask a question in one e-mail, but... in GM TPI EGR unit there is temp switch use to detect hot exhuaust gas under certain conditons. Trouble code 32. Paul, is the 86-89 ECM 1227165 calpak 16151348 eprom contents similar? if not what are the differences? Thanks Vance ------------------------------ From: peter paul fenske Date: Sun, 13 Oct 1996 23:13:03 -0700 Subject: Re Gm contollers Hi Vance The 165 Ecm is different, two plugs instead of three, uses a 27c128 instead of a 277c256. Generally used in Maf applications. Although do have one map driven calpak for a 2.5 tbi. If you are talking about 89 application with Vats I don't have the file so I am not sure. I have some for 87-88 without vats and they are some differences from the 90-92 730 application. Although the 165 uses an external knock amplifier while the calpak of the 730 contains the knock amp and controller. GL: peter >Paul, is the 86-89 ECM 1227165 calpak 16151348 eprom contents similar? if >not what are the differences? > >Thanks Vance > > > > > ------------------------------ End of DIY_EFI Digest V1 #313 ***************************** 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".