DIY_EFI Digest Monday, 3 June 1996 Volume 01 : Number 154 In this issue: General Motors ECM Re: General Motors ECM L-Jetronic EFI for Mazda Rotary Engine Re: L-Jetronic EFI for Mazda Rotary Engine Re: L-Jetronic EFI for Mazda Rotary Engine Re 2: General Motors ECM Ignition systems Re: Ignition systems See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: pfenske@xxx.ca (peter paul fenske) Date: Sun, 02 Jun 1996 09:17:45 -0700 Subject: General Motors ECM Hello everyone: Just wondering if anyone else is working on reverse engineering gm ECM. I have so far decripted spark timing, IAC, prom id, fan control and tcc. I am wondering if anyone else has decripted info on fuel control. I am guessing WOT is based on base PW modified by rpm vs VE chart with compensation for battery volt and temp. Still there are a great deal of lookup tables. CL also appears to be modified by block learn tables. Also does anyone have info on transient enrichment done by tps and map. I have prom dumps for 85 corvette, 87 iroc, 92 gm truck if anyone needs em. If any one has other prom dumps would appreciate them. In addition my HCll package has a hard time decripting 6801 code Does anyone know where a 01 dissembler can be found. Yess I could spend a day writing it in basic but. If anyone wants to help they can email me directly if they want. Thanks everyone Peter: pfenske@xxx.ca ------------------------------ From: arthurok@xxx.com (ARTHUR OKUN ) Date: Sun, 2 Jun 1996 19:30:25 -0700 Subject: Re: General Motors ECM how about the binary code for a 1988 buick regal both speed density and mass airflow i think the car uses a 68hc11 micro ? ------------------------------ From: Rob Skala Date: Mon, 03 Jun 1996 10:52:21 +0000 (WST) Subject: L-Jetronic EFI for Mazda Rotary Engine Hi All, It's time for me to ask for some advice and help. I recently obatined a replacement EFI controller for my 12A turbo rotary. I think its an L-Jetronic system from what I can work out. Anyway I need some help to identify some of the connections, I've managed to work most of them out using a copy of the wiring diagram from a Japanese workshop manual, but several of them still elude me...... I've included a list of the pins on the two connectors below. Hopefully someone out there may be able to help me out !!!! PIN ID: Connection PIN ID: Connection +B Power thru ign switch IGN ? (possibly coil ??) E2 Earth connection E1 Earth Connection Vc Airflow sensor Vs Airflow sensor Vb Airflow sensor Ox Oxygen sensor STA Starter switch Rv TPS Tau ??????? #10 Injector #1 Tl TPS #20 Injector #2 THA Air temp sensor E01 Ground Connection THW Coolant Temp sensor E02 Ground Connection +BF +12V for injectors Second Connector: TH ??????? IDL ??????? VF ??????? I think these connections are something to do PW ??????? with the emmission control system T ??????? LLD ??????? FC1 ??????? FC2 ??????? As you can see I've got most of them, it just the Tau and IGN pins. Anyone have any ideas ???? Thanks for all your help in advance...... Regards, Rob Robert D Skala Materials Research Group School of Physical Science Curtin University of Technology GPO Box U1987 Perth 6001 WESTERN AUSTRALIA Telephone: +61 9 351 2331 Fax: +61 9 351 2377 email: skala_rd@xxx.au ------------------------------ From: lambs@xxx.au (Stephen Lamb) Date: Mon, 3 Jun 1996 14:46:00 +1000 Subject: Re: L-Jetronic EFI for Mazda Rotary Engine > +B Power thru ign switch IGN ? (possibly coil ??) >As you can see I've got most of them, it just the Tau and IGN pins. >Anyone have any ideas ???? IGN almost certainly goes to the -ve terminal of the coil to provide the timing 'pulses' for the ECU. Sorry, can't help with the other. Cheers Stephen Lamb Dept. of Defence DSTO, AMRL 506 Lorimer Street Fishermans Bend VIC 3207 Australia Tel: +61 3 9626 7525 Fax: +61 3 9626 7089 IZCC #180 ------------------------------ From: Craig Pugsley Date: Mon, 3 Jun 1996 16:13:54 +1000 (EST) Subject: Re: L-Jetronic EFI for Mazda Rotary Engine > It's time for me to ask for some advice and help. I recently obatined a > replacement EFI controller for my 12A turbo rotary. I think its an > L-Jetronic system from what I can work out. I think they were L jet based, made by Nippon Denso. The 'Gregorys' fixing EFI books have wiring diagrams in them, many of the connections have the same name as in your list, so maybe a 626 turbo might have the same computer? http://proffa.cc.tut.fi/~k124476/vehicles/3T-GTEfi.html might be able to shed some light on some of the connections (this is a toyota 1.8l injected turbo computer) > PIN ID: Connection PIN ID: Connection > +B Power thru ign switch IGN ? (possibly coil ??) ^^^^^^^^^^^^ Yep. > E2 Earth connection E1 Earth Connection ^^^^^ for air flow meter ^^^^^ Main computer earth > Tau ??????? #10 Injector #1 ^^^^^^^ (GUESSING.. Maybe a boost switch?) > THW Coolant Temp sensor E02 Ground Connection ^^^^^^ return for injectors. > Second Connector: > > IDL ??????? ^^^^^^^ Idle contacts in throttle position switch > VF ??????? ^^^^^^^ This is supposedly a "Test socket" (What it's function is unknown, as these are analog computers - maybe an injector on-time control voltage) It seems that a lot of the connectors on the ND Ljet are similar (I have a 2 litre 929 Ljet unit with a lot of what you have listed). The turbo units with trapdoor sensors don't seem to need a MAP input, but the 3TGTEU has two pressure switches (one for boost enrichment, the other for boost limiting) Cheers, Craig. pugsley@xxx.au ------------------------------ From: pfenske@xxx.ca (peter paul fenske) Date: Sun, 02 Jun 1996 22:57:49 -0700 Subject: Re 2: General Motors ECM >how about the binary code for a 1988 buick regal both speed >density and mass airflow i think the car uses a 68hc11 micro ? >Hi >Would be an interesting look. Sure. Part of my initial look >was to spy on the GNs. Know most of the old code. But the 88 >was a P4 ecm(hc11 variant). Probably a 3.8 with sequential. >Interesting. >Tnx Peter ------------------------------ From: "SANDY" Date: Mon, 3 Jun 1996 09:01:47 UTC-2 Subject: Ignition systems I was reading a book on tuning by A Graham Bell (no, not the inventor of the telephone). He seems to highly recommend the Scintilla Vertex magneto ignition system. Apparently it was used in airplane engines in the 1950s. It was the first I'd heard about it. Does anyone have any experience of the system? This guy seems to think it's better than the electronic systems??? But then he also semms to think carbs are better than efi....... Sandy ====================================================================== DR. S.M. WELTAN DEPT OF PHYSIOLOGY Tel. No: (021) 406-6507 UNIVERSITY OF CAPE TOWN Fax No: (021) 47-7669 MEDICAL SCHOOL SOUTH AFRICA e-mail:sweltan@xxx.za ====================================================================== ------------------------------ From: arthurok@xxx.com (ARTHUR OKUN ) Date: Mon, 3 Jun 1996 01:51:58 -0700 Subject: Re: Ignition systems bendix is scintilla "allied signal" and versions of that magneto are still being used in present day light air craft engines "lycoming " and "continental most aircraft use 2 mags and 2 plugs per cylinder. what do you think lawnmower type ignition systems are just permanent magnet magnetos . the newer ones just use solid state stuff to get rid of the points and condenser. the faa likes it because it dosent require a working electrical system to keep the engine running. ------------------------------ End of DIY_EFI Digest V1 #154 ***************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. 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