DIY_EFI Digest Saturday, 29 June 1996 Volume 01 : Number 183 In this issue: 68HC11 Disassembler and AC Delco ECMs RE: Bosch Motronic AFM => Point - Counterpoint 6811 Disassembler... Bill Boulton Replies.... Re: DIY_EFI Digest V1 #182 See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Donald Whisnant Date: Fri, 28 Jun 1996 11:15:31 -0400 Subject: 68HC11 Disassembler and AC Delco ECMs I've noticed the recent postings by several people looking for a 68HC11 disassembler. Several months ago I mentioned the 68HC11 disassembler I wrote. It is a code seeking disassembler that actively separates code from data (you just give it a starting address, like reset vectors, etc). It is directly compatible with the asXXXX assemblers writen by Alan Baldwin (I think that is his name) at Kent State University in Ohio .... i.e. output disassembly when re-assembled by the as6811 assembler will match the original binary without modification... I would be willing to share it with the list... In hopes that some of you can help with my ECM project. I am working on reverse engineering the AC Delco ECM that came with my '94 4.3L V6 CMFI engine (eprom E6 code -- that came out of a '94 AstroVan) ... I've got all of the code actually disassembled, but now I'm working on figuring out what ports are what and what tables are what --- especially things like the speed limiters (for starters) ... Any information that you have that would help would be greatly appreciated .... I've recently put the engine in my '85 Grand Prix and will eventually replace it with my own DIY computer -- but first I want to look at and evaluate GM's algorithms (since they spent so much time and money developing and perfecting them)... If you would like a copy of the assembler, email me and I'll email you a copy of it -- tell me what encoding you want for the email (i.e. uuencode, mime, binhex, etc)... Donald Whisnant dewhisna@xxx.com ------------------------------ From: "Kenneth C. King" Date: Fri, 28 Jun 1996 16:55:44 -0500 (CDT) Subject: RE: Bosch Motronic AFM => Point - Counterpoint On Wed, 26 Jun 1996, Carter Hendricks wrote: > On Wed, 26 Jun 1996 WERNER_HAUSSMANN@xxx.com wrote: > > For the Bosch systems with the air meter, when changing the > > trottle, the air meter will overshoot, the ECU will sense the rate > > of change and provide an accelerator pump action. 'Loosening the spring' > > will increase that accelerator pump action. That is kind of the intend of the > > discussion. > Accelerator pumps are evil necessities required by carburators. > --Carter ummmm, close. it is needed by *all* wet flow intake manifolds. throttle body injectors (like holly's metered leak) need compensation for the change in the ability of the air to hold the fuel particles in suspension on a throttle transient. the exact physics have escaped my brain (it *is* after 5pm on a friday, ya know :) later, kc (re-engaging lurking device) - -- "ooooh, crumbs!"if the world is nite, shine my life like a lite"live your life with PASSION"hey waiter, there's a transvestite in my soup"hey mister, are you tall?"all alone in the nite"son of a son of a sailor"John DeArmond fanclub #13 "he's dead, jim"he's not dead, he's electroencephalographically challenged" kc ------------------------------ From: Donald Whisnant Date: Fri, 28 Jun 1996 19:45:45 -0400 Subject: 6811 Disassembler... Wow!... I've had a large turn out for the 68HC11 disassembler!! At this point, all of you that have written requesting the disassembler have either received it or a message from me saying that it is on the way... If you haven't heard from me, then possibly the message got lost (our mail server has been acting a little wierd --- I've lost over 5 messages this week that I've known about, no telling how many more) ... Hope the disassembler does at least one of you some good! Donald Whisnant dewhisna@xxx.com ------------------------------ From: William Boulton Date: Sat, 29 Jun 1996 11:42:21 +1000 (EST) Subject: Bill Boulton Replies.... Sorry to have to do this to you folks, but I am having difficulty with my e-mail. Generating individual replies is not practical at this time so I have been forced to lump all into one big blob. I've separated them as best I can. Thanks from a newbie, Bill Boulton =====John S Gwynne ================================= John, You are right. Sorry, no offence meant. Comes of joining a conversation already in progress. With 32bit processing and 60 tooth sensor input, most things must be trivial. I was refering to an inch by two of analogue device with only a trigger input which does not seem to me to be a trivial exercise. Bye for now, Bill Boulton =====Paul Beam ========================================= Paul, Thanks, truely. In Oz there a number of companies offering recalibrated memory chips for the unit and I have always had my doubts about their claims. After reading your message and the one from Peter, I have little doubt that the fertilizer industry is well and thriving down under. Probably elsewhere too. Do appreciate your input. Thanks for everything, Bill Boulton =====James Weiler ================================== James, Using TPS as load sense is fairly common and is the only viable system for normally aspirated and cammy motors. Without a respectable level of manifold vacuum at low throttle, a MAP sensor is next to useless and I think the reversion in the intake system would make a MAF little better. Throttle responce with a TPS/RPM system is about as good as it gets. The only requirement for street use is to make the system sensitive enough in the idle/off-idle/low load range (0-10%). By closing up the load sites at the low end, good transition is achievable and you will have the sweetest running sleeper possible. The simplest system I have seen for v8s is the Holley Pro-Jection system. It's a TBI unit that bolts on to a four barrel manifold. They have kits for small block motors in dual throat form delivering 670cfm at 1.5" Hg accross the butterfly. That's good for about 400bhp at 6500rpm. Don't worry about having only two throats. They are about 1.75" in dia with no ventuties. Beyond that, you move into the area of systems that are more expensive than the car. It's not just the box, it's all the other bits and bobs that cost buckets. Of the units I know, Motec 3D would be the pick of the bunch for entry level. Expensive, but the backing and reputation is impressive. Most Australian Group-As use its' big brother. On the subject of sensors. It's no good having more than can be effectively utilized. A basic systems needs load (throttle, map), crank speed, engine temperature (CST) and manifold air temperature (MAT). everything else is of decreasing benefit and will require time inversely proportional to its' benefit to utilize. In other words, the more you have, the longer it takes to dial it in for maximum efficiency. In the extreme, time to do a full dial-in of a Group A v8 with all its' facilities (individual cylinder trim, end of injection timing, etc) will see 8 to 10 hors and the motor going back for a rebuild when it comes off the dyno. It won't go near the car till the next time. That's why I suggested the Holley. It is almost crude in its' simplicity but still makes a carby look like a petrol soaked rag. Don't misunderstand fuel injection. It will not give more power than is achievable with a carby of the same flow capacity. But it will allow you to extract all of the power that has been built into the engine and it will be a far more tractable with few or no bad habits. There you go. That's my two cents worth I think. It's opinion, observation but not gospel. Others will have different ideas I know. GL, Bill Boulton. =====Mark Boxsell ==================================== Mark, Now you have aroused my curiosity. Tell me all about this nifty unit of yours. Sounds impressive. About the cost of the -008 modules, Fuel-Miser do replacements at lower prices. About $70.00 RRP I think. Connectors for the Bosch units are available from Petro-Ject. OK. So they aren't cheat either, but "When You Gotta Go, You Gotta Go!". yours Bill Boulton =====The End (at last)================================================ Thats all for now. I hope to have the problems sorted out soon and I can do the job properly. Sometimes Unix is a ................ ------------------------------ From: "The Fraser's" Date: Fri, 28 Jun 1996 22:39:57 -0500 Subject: Re: DIY_EFI Digest V1 #182 > Sounds like just the unit I'm looking for. Got part #'s, car models, years > used etc. to facilitate a junkyard search? I had no idea GM was still using > a frequency output MAF. > > BTW, as far as air flow measurement, you could always dangle it out the window > of your favorite ride, and drive down the nearest interstate at 130+ MPH like > Peter Wales did! ;] Seriously, this may be a simple way to check how high > the output goes. Just go until the output equals your best previous reading, > and keep going... (Could always see if you can get a surplus JATO bottle if > your ride won't go fast enough :O) Disclaimer: This should only be > attempted by professional drivers on closed roads... > > regards > dn > > ------------ Thanks for the reply, To answer your question, the Air-Mass Sensor I mentioned is used on all 94-96 LT1 engines, as well as all 96 Vortec truck engines. It may be on more as well, but These applications come to mind. There are many ways to experimentally determine the limits of the sensor, but I was just wondering if somebody already knew.... Thanks! Brock Fraser Hypertech, Inc. ------------------------------ End of DIY_EFI Digest V1 #183 ***************************** 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".