DIY_EFI Digest Sunday, 24 November 1996 Volume 01 : Number 359 In this issue: Hello...short introduction... Re: Air flow measurement Re: Hello...short introduction... RE: winmail.dat attachments Oliver's ALDC converter...was Re: Hello...short introduction... See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: "Curt Martin" Date: Sat, 23 Nov 1996 11:17:26 -0500 Subject: Hello...short introduction... Hi, Just wanted to introduce myself, I just joined this list. I've been tinkering with cars for a while and want to learn more about how engine management systems work. My "toy" is an '87 V6 MPFI Camaro thats been a project. (currently being retrofitted with a V8 TPI ) I've just started working with a ALDC to RS-232 converter made by Oliver Scholz (from the Fiero e-mail list) to start figuring out the serial output of the GM computer. Now, if y'all don't mind, l'd like to hang out and listen. Curt Martin (cmartin@xxx.com) Ormond Beach, Florida http://www.america.com/~cmartin/ ------------------------------ From: Mazda Ebrahimi Date: Sat, 23 Nov 1996 13:17:54 -0500 Subject: Re: Air flow measurement To Tom Cloud (and everybody else): I want to put up another aspect of using TPS and delta P and IAT for flow measurement. As the gentelman from Orbital (forgive me for not remembering your name, but I erased all my message files...) pointed out, air flow reversion causes an error in MAF systems. Wouldn't these same dynamic flow characteristics cause an error with the TPS method (especially at WOT)? Also, a while ago I read (somewhere) about a flapper system being tested for introduction on some Cadillac engines. Each intake runner would have a flapper in it (near the intake valve) that prevented flow from comming back into the plenum. I believe at the time the system had met their durability requirements, but they were concerned about additional noise because of their luxury line of cars. Has anyone else heard anything about this? Not only will this flapper possibly allow more valve openning duration, but it would minimize pressure pulses in the manifold. Judging from our discussions so far, no matter what kind of measurement system is used, the results would be more accurate using this system. Right? Best Regards, Mazda Ebrahimi ------------------------------ From: "John Faubion" Date: Sat, 23 Nov 1996 22:14:53 -0600 Subject: Re: Hello...short introduction... > Just wanted to introduce myself, I just joined this list. I've been Welcome to the list! > I've just started working with a ALDC to RS-232 converter made by Oliver > Scholz (from the Fiero e-mail list) to start figuring out the serial output > of the GM computer. Curt could you give some more information about this converter? I'm interested in building a similar device myself. I'd appreciate any info I can get. John Faubion jfaubion@xxx.net ------------------------------ From: Doug Rorem Date: Sat, 23 Nov 1996 23:43:40 -0600 Subject: RE: winmail.dat attachments >> >>>> Can someone guide me to descramble this? >> >>>i tried xferpro,(a mail-format de-scrambler, a must when transferring >>>thru some services) all formats with no luck. sorry. >> >>I've resent the message you're trying to unscramble. >> >>It looked to me like the scrambled version was uuencoded. >>(If you're on a Unix machine, check the man pages for >>uuencode and uudecode.) That format was entirely >>unintentional on my part. I'm trying for straight ASCII. >> >>Anthony Tsakiris >> >>begin 600 WINMAIL.DAT >>M>)\^(C,-`0:0" `$```````!``$``0>0!@`(````Y 0```````#H``$(@ <` >> 23-nov-96 Anthony, Microsoft Exchange appends this stuff apparently by default (you have to explicitly shut it off for each email address you send to).... It apparently is a duplicate of the clear text (ASCII) email, except in uuencoded Microsoft RTF [Rich Text Format] which is unusable to people not using Microsoft mailers. Microsoft has a page that deals with this specific problem "XFOR: Preventing WINMAIL.DAT Sent to Internet Users" http://www.microsoft.com/kb/articles/q138/0/53.htm - -- Doug Rorem University of Illinois at Chicago (312)-996-5439 [voice] EECS Department RM 1120 (312)-413-1065 [fax] 851 S. Morgan Street (708)-996-2226 [pager] Chicago, IL 60607-7053 rorem@xxx.edu ------------------------------ From: "Curt Martin" Date: Sun, 24 Nov 1996 02:57:50 -0500 Subject: Oliver's ALDC converter...was Re: Hello...short introduction... > > I've just started working with a ALDC to RS-232 converter made by Oliver > > Scholz (from the Fiero e-mail list) to start figuring out the serial > output > > of the GM computer. > > Curt could you give some more information about this converter? I'm > interested in building a similar device myself. I'd appreciate any info I > can get. > > John Faubion John, (and also Scott Feaver and Martin Scarr who asked the same question) Oliver's ALDC to RS232 converter is a simple microcontroller that plugs into pins A,B, and E of the ALDC port on the GM wiring harness. It takes the 160Hz bits and formats them as 8,N,1 ASCII at 4800bps. Then pumps that out a 9-pin d-sub for use with PC serial ports. The converter has several output modes. One converts the data to readable form (i.e. the RPM bits are converted to an string like "2800") with commas seperating each data value. A second mode grounds pin B and dumps the error codes out. The third mode is a "raw" format (no conversion except framing the bits into the 8,N,1 format so the PC port can see them as characters.) Oliver is into Fiero's, so naturaly, the only two motor/ecm combos that it decodes completely are the VIN "9" 2.8L V6 and the VIN "R" 2.5L L4 I've hooked it up to my VIN "S" '87 Camaro and it does decode most of the values (rpm, IAC, coolant temp, TCC, integrator, TPS, O2 rich/lean, Loop, etc.) Some of the values that don't decode or I question are the MAT, MAF (not suprised, the Fiero is a MAP system), and AC settings. The car is 10 years old and has a flaky idle to start with, so I may have a few bad sensors... I still have to go through the system sensor by sensor. I'm not getting an SES light or error codes, so nothing has failed completely. Oliver's web page is... http://www.franken.de/users/degobah/luke/scantool.html hope this helps, ------------------------------ End of DIY_EFI Digest V1 #359 ***************************** 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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