DIY_EFI Digest Monday, March 20 2000 Volume 05 : Number 114 In this issue: Newbies, and archives Re: hall sensor simple questions Re: hall sensor simple questions Re: hall sensor simple questions Re: hall sensor simple questions Hall sensor Re: Newbies, and archives Re: Hall sensor I another new guy..... Re: I another new guy..... Nissan JECS ECU RE: I another new guy..... Re: Nissan JECS ECU RE: I another new guy..... Re: DIY_EFI Digest V5 #112 Re: DIY_EFI Digest V5 #112 Re: Chip burning 101? (Or, newby questions II) Re: hall sensor simple questions Re: hall sensor simple questions Re: Nissan JECS ECU RE: I another new guy..... Re: Hall sensor K-Jet on the water (well, maybe not) See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Mon, 20 Mar 2000 08:13:28 -0500 From: "nacelp" Subject: Newbies, and archives If you want to start catching up on your reading, and figuring out EFI, here are the archives in downloadable form. Might as well just start reading the DIY and GMECM stuff from the beginning there is a ton of good info here. I've been reading them for several years, and I'll be darned if someone doesn't keep adding new stuf into the old areas. While these aren't up to date the the DIY is 12 Meg of must read stuff. I just downloaded all 3 to see what it takes to do, less than an hour at 4-4.5Kb/sec 56 Modem. Cheers Grumpy ftp://diy-efi.org/incoming/GM_ECMArchives.zip ftp://diy-efi.org/incoming/DIY_EFIArchives.zip ftp://diy-efi.org/incoming/EFI332Archives.zip - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Mon, 20 Mar 100 22:20:48 +0800 (WST) From: Bernd Felsche Subject: Re: hall sensor simple questions Toby Atwater writes: >As I understand it, a hall sensor can detect a metal mass approaching the >sensor i.e. a distributor cam rotating and a hall sensor sensing the lobes. The Hall sensor picks up a chnage in the magnetic field. It can be used to sense the position of a camshaft drive gear tooth. "Reluctance" sensore are also used commonly. A reference signal to identify a particular tooth on the gear wheel is used so that the absolute position of the camshaft can be determined. If you're using an encoder wheel, the most accurate (but also more costly) method, then a "missing tooth" is quite a common method of identifying one particular position. >Crank shaft sensors can determine the position of the piston and therefore >give the ECU a timing reference inorder to inject fuel at the right time. The sensors are used to sense the position of the crankshaft, not the piston. The crankshaft detrmines the relative locations of the pistons. >How many sensors do you need around the crank inorder to get a resolution >that is useful? Is this multiplied by each cylinder as well? or can the ECU >calculate where one piston is compared to another's location? You *need* none at all. Basic engine timing can be determined from the camshaft position, with a TDC and BDC signal required as a minimum. The ECU can interpolate intermediate positions given the elapsed time between TDC and BCD. >Crank shaft sensors seem hard to implement on an old engine with no stock >electronics what so ever. I was thinking about using the distributor's cam >with a hall sensor in order to get spark timing and as well as Fuel >Injection timing and thereby doing away with crank sensors completely. Is >this possible? are the hall sensors accurate enough to not only detect a >lobe peak but the lobe's approach and exit? The common method is to use a magnet with an "interruptor" wheel. Edges of the openings are treated (nominally) as the TCD position for each cylinder - the Hall sensor is accurate if the distributor does not have any advance mechanism. Such a method has in the past been employed successfully by VW's Digifant, which integrates fuel injection and ignition. More accuracy is possible with camshaft and/or crankshaft sensing to detect transitions in engine speed more easily and reliably; as well as allowing sequential injection and other goodies. - -- Real Name: Bernd Felsche Email: nospam.bernie@xxx.au http://www.perth.dialix.com.au/~bernie - Private HP - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Mon, 20 Mar 2000 09:32:06 -0500 From: "nacelp" Subject: Re: hall sensor simple questions > >As I understand it, a hall sensor can detect a metal mass approaching the > >sensor i.e. a distributor cam rotating and a hall sensor sensing the lobes. > > The Hall sensor picks up a chnage in the magnetic field. It can be > used to sense the position of a camshaft drive gear tooth. ?. What signifigance is a camshaft drive tooth. Camshaft posistion sensor, yes, the two thou are entirely different, the posistion sensor is to find a relative TDC, or sync for a specific cylinder. The only thing constant about camshaft gear teeth is that there is an even number. > "Reluctance" sensore are also used commonly. A reference signal to > identify a particular tooth on the gear wheel is used so that the > absolute position of the camshaft can be determined. If you're using > an encoder wheel, the most accurate (but also more costly) method, > then a "missing tooth" is quite a common method of identifying one > particular position. Actually a missing notch is best. Take a steel wheel, and cut several notches into it. Those are easiest to find. Specially at cranking speeds. > >Crank shaft sensors can determine the position of the piston and therefore > >give the ECU a timing reference inorder to inject fuel at the right time. > The sensors are used to sense the position of the crankshaft, > not the piston. The crankshaft detrmines the relative locations of > the pistons. > >How many sensors do you need around the crank inorder to get a resolution > >that is useful? Is this multiplied by each cylinder as well? or can the ECU > >calculate where one piston is compared to another's location? > You *need* none at all. Basic engine timing can be determined from > the camshaft position, with a TDC and BDC signal required as a > minimum. The ECU can interpolate intermediate positions given the > elapsed time between TDC and BCD. If your implying just two distributor reference pulses good luck. I'd imagine real hard starting in cold weather when the cranking speed is erratic. I'd use at least one notch for every two cylinders if crank, and 1 per cylinder distributor, as mins. > >Crank shaft sensors seem hard to implement on an old engine with no stock > >electronics what so ever. I was thinking about using the distributor's cam > >with a hall sensor in order to get spark timing and as well as Fuel > >Injection timing and thereby doing away with crank sensors completely. Is > >this possible? are the hall sensors accurate enough to not only detect a > >lobe peak but the lobe's approach and exit? > > The common method is to use a magnet with an "interruptor" wheel. > Edges of the openings are treated (nominally) as the TCD position > for each cylinder - the Hall sensor is accurate if the distributor > does not have any advance mechanism. ???, the sensor in it's operation don't care if there is an advance mechanism. If there is a timing problem in the advance mechanisms, then timing will be erratic. Just the same as if there were points, IR detector or anything else triggering off of the distributor shaft. > Such a method has in the past been employed successfully by VW's > Digifant, which integrates fuel injection and ignition. More > accuracy is possible with camshaft and/or crankshaft sensing to > detect transitions in engine speed more easily and reliably; as well > as allowing sequential injection and other goodies. ??. Accuracy (at least in the mechanical sense), is a function of the number of references, not number of sensors. You can do equally well with crank or cam, the only time you need both is in SEFI (meaning timing or fuel). If you want to measure crankshaft accleration rates accurately then you need a crank sensor, since there is always "gearing" for the distributor, and that alllows for slow, and erratic signaling for that level of resolution, needed. You can get by with dissy, but the resolution of input, and filtering gets more complex, and hence more room for error. > > -- > Real Name: Bernd Felsche > Email: nospam.bernie@xxx.au > http://www.perth.dialix.com.au/~bernie - Private HP > -------------------------------------------------------------------------- - -- > To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) > in the body of a message (not the subject) to majordomo@xxx.org > - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Mon, 20 Mar 2000 09:58:11 -0500 From: "Swayze" Subject: Re: hall sensor simple questions so, if using a dissy for the timing pulse, you would still need a TDC reference (either missing or extra tooth(notch) or extra sensor(crankshaft?) byE Mike Swayze mswayze@xxx.com kswayze@xxx.net .................... > ??. Accuracy (at least in the mechanical sense), is a function of the number > of references, not number of sensors. You can do equally well with crank or > cam, the only time you need both is in SEFI (meaning timing or fuel). If > you want to measure crankshaft accleration rates accurately then you need a > crank sensor, since there is always "gearing" for the distributor, and that > alllows for slow, and erratic signaling for that level of resolution, > needed. You can get by with dissy, but the resolution of input, and > filtering gets more complex, and hence more room for error. > > .... - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Mon, 20 Mar 2000 10:30:51 -0500 From: "nacelp" Subject: Re: hall sensor simple questions GM has used the distributor pulse (only) for EFI for hundreds if not thousands of applications. They set the intial timing at say 6d BTDC, so that in a faliure mode there is enough timing for the engine to at least sorta run to get you home. They use a matching number of distributor reference pulses to the number of cylinders. (also, since it's reluctor style there is some self advancing characteristics that help with that). Now for SEFI (timing or fuel control), then you need an addition sensor to sync things to number 1, or what ever your reference cylinder is (not all engines are built on number one, is why I mention that). Now for individual cylinder timing control in a feedback system (ie knock sensor), then you even to sync the knock sensor to cylinder, and/or measure crank shaft accleration rates. Which means a very high resolution sensor. Grumpy - ----- Original Message ----- From: Swayze To: Sent: Monday, March 20, 2000 9:58 AM Subject: Re: hall sensor simple questions > so, if using a dissy for the timing pulse, you would still need a TDC > reference (either missing or extra tooth(notch) or extra > sensor(crankshaft?) > byE > Mike > Swayze > mswayze@xxx.com > kswayze@xxx.net > .................... > > ??. Accuracy (at least in the mechanical sense), is a function of the > number > > of references, not number of sensors. You can do equally well with crank > or > > cam, the only time you need both is in SEFI (meaning timing or fuel). If > > you want to measure crankshaft accleration rates accurately then you need > a > > crank sensor, since there is always "gearing" for the distributor, and > that > > alllows for slow, and erratic signaling for that level of resolution, > > needed. You can get by with dissy, but the resolution of input, and > > filtering gets more complex, and hence more room for error. > > > > .... > > -------------------------------------------------------------------------- - -- > To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) > in the body of a message (not the subject) to majordomo@xxx.org > - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Mon, 20 Mar 2000 09:47:47 -0800 (PST) From: Carter Shore Subject: Hall sensor An FYI, just in case, since it was not specifically stated. Hall effect sensors change state when magnetic field density reaches an internally set threshold. So make sure you use a ferrous metal to interrupt a biasing magnetic field (reluctor), or magnets. Some Hall sensors are built with magnet already in the package, easy to check with a piece of steel. Hate for anyone to go to the trouble of machining a shutter or timing wheel in aluminum, only to see it not work properly. Carter __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Mon, 20 Mar 2000 10:13:47 -0800 From: Doug Dayson Subject: Re: Newbies, and archives Thanks Grumpy...appreciate it... Doug nacelp wrote: > > If you want to start catching up on your reading, and figuring out EFI, here > are the archives in downloadable form. Might as well just start reading the > DIY and GMECM stuff from the beginning there is a ton of good info here. > I've been reading them for several years, and I'll be darned if someone > doesn't keep adding new stuf into the old areas. > While these aren't up to date the the DIY is 12 Meg of must read stuff. > I just downloaded all 3 to see what it takes to do, less than an hour at > 4-4.5Kb/sec 56 Modem. > Cheers > Grumpy > > ftp://diy-efi.org/incoming/GM_ECMArchives.zip > ftp://diy-efi.org/incoming/DIY_EFIArchives.zip > ftp://diy-efi.org/incoming/EFI332Archives.zip > > ---------------------------------------------------------------------------- > To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) > in the body of a message (not the subject) to majordomo@xxx.org - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Mon, 20 Mar 2000 12:56:36 -0600 From: MysticZ Subject: Re: Hall sensor Carter Shore wrote: > > Hate for anyone to go to the trouble of machining a > shutter or timing wheel in aluminum, only to see it > not work properly. In that case you get to use the same setup as the distributor in my Camaro: optical. Unfortunately the setup tends to go straight to hell in 30-80k miles :( - -- Steve 97 Chevy Camaro Z28, Mystic teal, A4, not stock 90 Kawasaki EX500A4, black, M6, not even CLOSE to stock! lt1_z28@xxx.net/~lt1_z28 Aluminum, steel, carbon fiber, titanium, and two cast iron balls. McMillan Motorsports- http://www.mmsbikes.com - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Mon, 20 Mar 2000 13:12:14 -0600 From: "BOWEN, SCOTT M. (JSC-CC)" Subject: I another new guy..... I just wanted to say hello to the DIY_EFI list. My name is Scott Bowen and I am looking to modify the Nissan/JECS system instead of paying Jim Wolf Technologies $700 to do it and $100 for each change I want done after that. By purchasing their system, I will not learn anything.... I have been going through the archives in search of any information with the JECS system, but have yet to find any. If anyone has any information on this system, could you please get in touch with me? Thanks, Scott Bowen Bastard Motorsports Engineering Houston, TX - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Mon, 20 Mar 2000 15:34:16 -0500 From: "nacelp" Subject: Re: I another new guy..... If anyone sees hears smells of any editors for the Nissan, Toyo, Madsa, I'd like to hear about it. Seems like there is utter silence on these ecms Grumpy > I just wanted to say hello to the DIY_EFI list. > My name is Scott Bowen and I am looking to modify the Nissan/JECS system > instead of paying Jim Wolf Technologies $700 to do it and $100 for each > change I want done after that. By purchasing their system, I will not learn > anything.... > I have been going through the archives in search of any information with the > JECS system, but have yet to find any. > If anyone has any information on this system, could you please get in touch > with me? > Thanks, > Scott Bowen > Bastard Motorsports Engineering > Houston, TX - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Mon, 20 Mar 2000 15:12:37 -0600 From: "BOWEN, SCOTT M. (JSC-CC)" Subject: Nissan JECS ECU RE: I another new guy..... Well... My Nissan/JECS setup is out of a 1991 240SX with the KA24DE engine [2.4l DOHC] and I have found out a few things. The ECU, with board #A12-001 B52, has a 40 pin port on the board just right for a ribbon harness connector... It has one 84 pin processor with a JECS part number[M3M7790STJ], but they don't make it [of course] and they will not tell me who does [Oh, sorry, Nissan owns that information], a JECS chip is a 68 pin [M6M72561J-I] and a NEC 44 pin [D65012L(A)904]. Jim Wolf has informed me that the JECS 84 pin is the processor and the JECS 68 pin is the FLASH/A-D converter/microprocessor start up chip. The NEC helps with whatever the 64 pin JECS chip can't handle. Jim wolf has figured out how to input it's own program by using a daughter board that connects via the 40 pin port, and can you believe the guy's won't give me any ore info than that? I have not given up yet! That is why I found this list... I have also found a freeware program for editing Nissan EPROMS that works great on the '89-'90 KA24E 12valve motor ECU as it has an EPROM [27C256]. If anyone wants it, I will send it to them.... Scott Bowen Bastard Motorsports Engineering Houston, TX 281-244-9669 - -----Original Message----- From: nacelp [mailto:nacelp@xxx.net] Sent: Monday, March 20, 2000 2:34 PM To: diy_efi@xxx.org Subject: Re: I another new guy..... If anyone sees hears smells of any editors for the Nissan, Toyo, Madsa, I'd like to hear about it. Seems like there is utter silence on these ecms Grumpy - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Mon, 20 Mar 2000 17:41:37 -0500 From: "Swayze" Subject: Re: Nissan JECS ECU RE: I another new guy..... had a little free time ,part# search at ST Micro on one of the chips mentioned yielded an MCU ST7250. don't know if its relevant or not. I can send you the .pdf if you want it. the other numbers only gave serial transmisiion/encoder stuff with partial relevance. Dogpile kept throwing up virtual interface architecture on any of the ECCS searches byE Mike Swayze mswayze@xxx.com kswayze@xxx.net - ----- Original Message ----- From: "BOWEN, SCOTT M. (JSC-CC)" To: Sent: Monday, March 20, 2000 4:12 PM Subject: Nissan JECS ECU RE: I another new guy..... > Well... > > My Nissan/JECS setup is out of a 1991 240SX with the KA24DE engine [2.4l > DOHC] and I have found out a few things. > > The ECU, with board #A12-001 B52, has a 40 pin port on the board just right > for a ribbon harness connector... > > It has one 84 pin processor with a JECS part number[M3M7790STJ], but they > don't make it [of course] and they will not tell me who does [Oh, sorry, > Nissan owns that information], a JECS chip is a 68 pin [M6M72561J-I] and a > NEC 44 pin [D65012L(A)904]. > ......... - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Tue, 21 Mar 2000 08:02:09 -0800 From: Todd Israels Subject: Re: DIY_EFI Digest V5 #112 At 08:32 PM 3/19/00 -0800, you wrote: >DIY_EFI Digest Sunday, March 19 2000 Volume 05 : Number 112 > > > >Date: Sun, 19 Mar 2000 09:18:50 -0500 >From: "Swayze" >Subject: Re: Subject: Re: water into efi system before injectors. > >I have a manual on the dual fuel 90-91 lumina, seems it had some sort of >sensor on the fuel line to determine the percentage of alchohol in the >fuel. any idea how it would work? >byE >Mike >Swayze >mswayze@xxx.com >kswayze@xxx.net I read a paper on that just before the car went into production. Fuzzy recollection says it was done with a light beam and a sensor that measured the light refraction, don't know if it went in to production that way or it was just an idea that they were working with. Todd Israels - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Tue, 21 Mar 2000 07:58:38 -0800 From: Todd Israels Subject: Re: DIY_EFI Digest V5 #112 At 08:32 PM 3/19/00 -0800, you wrote: >DIY_EFI Digest Sunday, March 19 2000 Volume 05 : Number 112 > > > >Date: Sun, 19 Mar 2000 09:18:50 -0500 >From: "Swayze" >Subject: Re: Subject: Re: water into efi system before injectors. > >I have a manual on the dual fuel 90-91 lumina, seems it had some sort of >sensor on the fuel line to determine the percentage of alchohol in the >fuel. any idea how it would work? >byE >Mike >Swayze >mswayze@xxx.com >kswayze@xxx.net I read a paper on that just before the car went into production. Fuzzy recollection says it was done with a light beam and a sensor that measured the light refraction, don't know if it went in to production that way or it was just an idea that they were working with. Todd Israels - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Mon, 20 Mar 2000 20:20:44 -0600 From: "Dave & Irina Eicher" Subject: Re: Chip burning 101? (Or, newby questions II) Hi Steve, I resonate with you wholeheartedly on that one! I'm putting an LS1 from a 1998 Camaro in my 1964 Impala SS, hoping to figure out how to tune it, want to add a blower at some point. Don't know of anyone who can program them except places like EIS who charge several hundred dollars. I plan to work on hacking my way into the thing once I get it running but figure I'll be a very old man before I figure it out. dave 1964 Impala SS - ----- Original Message ----- From: MysticZ To: Sent: Sunday, March 19, 2000 10:31 PM Subject: Re: Chip burning 101? (Or, newby questions II) > nacelp wrote: > > > > pick up, rather then a 98 camaro pcm, least around here. > > If someone figures out how to reprogram a 98 (actually 97) Camaro ECM, > PLEASE let me know! I have the schematics and stuff for messing with 94 > and 95, but 96+ is OBDII and next to impossible to fiddle with :( > -- > Steve > 97 Chevy Camaro Z28, Mystic teal, A4, not stock > 90 Kawasaki EX500A4, black, M6, not even CLOSE to stock! > lt1_z28@xxx.net/~lt1_z28 > Aluminum, steel, carbon fiber, titanium, and two cast iron balls. > McMillan Motorsports- http://www.mmsbikes.com > -------------------------------------------------------------------------- - -- > To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) > in the body of a message (not the subject) to majordomo@xxx.org > > - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Tue, 21 Mar 100 10:50:00 +0800 (WST) From: Bernd Felsche Subject: Re: hall sensor simple questions nacelp writes: >> >As I understand it, a hall sensor can detect a metal mass approaching the >> >sensor i.e. a distributor cam rotating and a hall sensor sensing the >lobes. >> The Hall sensor picks up a chnage in the magnetic field. It can be >> used to sense the position of a camshaft drive gear tooth. >?. What signifigance is a camshaft drive tooth. >Camshaft posistion sensor, yes, the two thou are entirely different, the >posistion sensor is to find a relative TDC, or sync for a specific cylinder. >The only thing constant about camshaft gear teeth is that there is an even >number. The camshaft position is indicative of the piston "position" and the "stroke" (i.e. if it's induction or power for example). As it rotates at half the crank speed, you can identify for example which injector and plug to fire with a solid-state ignition. >> "Reluctance" sensore are also used commonly. A reference signal to >> identify a particular tooth on the gear wheel is used so that the >> absolute position of the camshaft can be determined. If you're using >> an encoder wheel, the most accurate (but also more costly) method, >> then a "missing tooth" is quite a common method of identifying one >> particular position. >Actually a missing notch is best. Take a steel wheel, and cut several >notches into it. Those are easiest to find. Specially at cranking speeds. >> You *need* none at all. Basic engine timing can be determined from >> the camshaft position, with a TDC and BDC signal required as a >> minimum. The ECU can interpolate intermediate positions given the >> elapsed time between TDC and BCD. >If your implying just two distributor reference pulses good luck. I'd >imagine real hard starting in cold weather when the cranking speed is >erratic. > I'd use at least one notch for every two cylinders if crank, and 1 per >cylinder distributor, as mins. There is one "mark" for every TDC in a four-cylinder engine - which if it's a conventional layout. So you get two pulses per crankshaft revolutions, just like in a Kettering ignition. >> >Crank shaft sensors seem hard to implement on an old engine with no stock >> >electronics what so ever. I was thinking about using the distributor's >cam >> >with a hall sensor in order to get spark timing and as well as Fuel >> >Injection timing and thereby doing away with crank sensors completely. Is >> >this possible? are the hall sensors accurate enough to not only detect a >> >lobe peak but the lobe's approach and exit? >> The common method is to use a magnet with an "interruptor" wheel. >> Edges of the openings are treated (nominally) as the TCD position >> for each cylinder - the Hall sensor is accurate if the distributor >> does not have any advance mechanism. >???, the sensor in it's operation don't care if there is an advance >mechanism. If there is a timing problem in the advance mechanisms, then >timing will be erratic. Just the same as if there were points, IR detector >or anything else triggering off of the distributor shaft. The sensor may not car, but your ECU is going to have a big problem trying to determine precise times for ignition and injection. The ECU would have to reverse-map the mechanical advance and overlay the vacuum advance/retard as well. The variable-advance distributors also introduce an amount of jitter if you have to rely solely on the distributor signal for timing. >> Such a method has in the past been employed successfully by VW's >> Digifant, which integrates fuel injection and ignition. More >> accuracy is possible with camshaft and/or crankshaft sensing to >> detect transitions in engine speed more easily and reliably; as well >> as allowing sequential injection and other goodies. >??. Accuracy (at least in the mechanical sense), is a function of the number >of references, not number of sensors. You can do equally well with crank or I think I said that. The Digifant architecture (similar to L-Jetronic) has only the pulses from the Hall sensor in the distributor as a timing reference. Digifant's "cousin", Motronic, has crank-angle (and optionally camshaft) position sensing. >cam, the only time you need both is in SEFI (meaning timing or fuel). If >you want to measure crankshaft accleration rates accurately then you need a >crank sensor, since there is always "gearing" for the distributor, and that >alllows for slow, and erratic signaling for that level of resolution, >needed. You can get by with dissy, but the resolution of input, and >filtering gets more complex, and hence more room for error. I think I said that. I apologise for not explaining it in sufficient detail. - -- Real Name: Bernd Felsche Email: nospam.bernie@xxx.au http://www.perth.dialix.com.au/~bernie - Private HP - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Tue, 21 Mar 100 10:55:34 +0800 (WST) From: Bernd Felsche Subject: Re: hall sensor simple questions Swayze writes: >> ??. Accuracy (at least in the mechanical sense), is a function of the >number >> of references, not number of sensors. You can do equally well with crank >or >> cam, the only time you need both is in SEFI (meaning timing or fuel). If >> you want to measure crankshaft accleration rates accurately then you need >a >> crank sensor, since there is always "gearing" for the distributor, and >that >> alllows for slow, and erratic signaling for that level of resolution, >> needed. You can get by with dissy, but the resolution of input, and >> filtering gets more complex, and hence more room for error. >so, if using a dissy for the timing pulse, you would still need a TDC >reference (either missing or extra tooth(notch) or extra >sensor(crankshaft?) No. The position signal from the distributor is sufficient. It can provide a reliable "TDC" reference. You can run an engine well on that. You can run an engine _better_ with higher resolution sensing via crank/cam position. - -- Real Name: Bernd Felsche Email: nospam.bernie@xxx.au http://www.perth.dialix.com.au/~bernie - Private HP - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Mon, 20 Mar 2000 21:27:25 -0800 From: Ludis Langens Subject: Re: Nissan JECS ECU RE: I another new guy..... "BOWEN, SCOTT M. (JSC-CC)" wrote: > > My Nissan/JECS setup is out of a 1991 240SX with the KA24DE engine [2.4l > DOHC] and I have found out a few things. > > It has one 84 pin processor... A neighbor and I popped open the ECU of an '85 or so 300ZX engine. It used a Motorola 6802 along with several other 40 pin DIPs. It appeared to have a mask ROM or an OTP PROM. There was no unplugable EPROM. - -- Ludis Langens ludis (at) cruzers (dot) com Mac, Fiero, & engine controller goodies: http://www.cruzers.com/~ludis/ - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Mon, 20 Mar 2000 20:08:32 +0000 From: Ade + Lamb Chop Subject: Re: Hall sensor At 09:47 20/03/00 -0800, Carter Shore wrote: >An FYI, just in case, since it was not specifically >stated. Hall effect sensors change state when magnetic >field density reaches an internally set threshold. > >So make sure you use a ferrous metal to interrupt a >biasing magnetic field (reluctor), or magnets. >Some Hall sensors are built with magnet already in the >package, easy to check with a piece of steel. > >Hate for anyone to go to the trouble of machining a >shutter or timing wheel in aluminum, only to see it >not work properly. So Hall effect sesors don't need a magnet on the thing that is moving? It just has to be ferous... Ade - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ Date: Tue, 21 Mar 100 16:14:00 +0800 (WST) From: Bernd Felsche Subject: K-Jet on the water (well, maybe not) Ken Thompson writes: >From: >Kevin Jaeger (Ken's Associate) >Bernd, >I apologise for my apparent heaviness of comment in relation to your >statement "K-Jet would be OK for boat". ... Apology accepted. We all have our "hot points". You touched one of mine when you called K-Jet a "diabolical mouse-trap". :-) It does appear that you read too much into what I wrote - I did actually express concerns about corrosion resistance (I thought it was zinc used for the flow-meter body and have been subsequently corrected). >All pleasure boats induct the spray of salt water (ocean going), it is the >nature of the beast. ... Salt corrosion could be the big problem. Although the systems have to cope with a small amount of salt in the air, the airborne amounts in the spray are more persistent than the seasonal rituals experienced in the the colder parts of the world. Excluding the spray would be difficult. The system simply has to be tolerant of it and/or require greater maintenance. >I am sure you could do a great job rigging up a K-Jet that would function >wonderfully on the water (the first day). Two weeks later, I will bet the >second days fun will not be as much fun. One can construct well designed air >boxes, centrifuges etc and salt spray is still going to be induced. Seizure >of the actuator, the arm roller etc is likely to be a problem (air valve >arm). Might be fine the day of commissioning, but put it away and come back >in two weeks, rust will be a problem. Benz' and others you mentioned have >got pretty good air filtration systems, but I do not see one system in >amongst them, that could double as a watercraft water excluder (for want of >a more suitable description). What is in a car would be largely unsuitable to exclude the spray. I've never designed an air induction and filtration system for such a task; I'd be tempted to do it in a couple of stages, starting with the inlet tube - directed to minimise spray induction. A cyclonic arrangement can then be used to get rid of most of the larger water droplets carrying the salt. The air would then be ducted to a large box around the exhaust manifold to evaporate the remaining droplets followed by another "cyclone" (a couple of sharp bends should do the trick) and filter to capture before a "charge cooler" and the final air filter leading to the metering unit. Most of that stuff doesn't need to weigh much; it just takes space. Before you put the boat "to bed" after a run, open up a trap-door in in the duct to the metering unit and give it a squirt of WD spray with the engine revving. >Who cares if Lucas' A/F ratio is not perfect, never said it was. It can be >set up pretty good www.kinsler.com Lucas was used in Formula One on down, >was very big in boats. A pleasure boat is more like a performance engine >than a street trim BMW. Not much stop start driving or gear changes. If 3000 >RPM is where it will be driven, would be nice to tune for max torque there. No arguments here. But BMW owners might have frowns on their brows ;-) >The Lucas (Triumph) bodies do lend themselves to simple set up for tuned >length runners. After a day on the water, give the each port a spray with >non waxing, dewatering compound. The Triumph runners would have plenty of >velocity to purge any water that would be inducted. The velocity in the >nooks and crannies inside the K-Jet main box (I call it this, for those not >familiar with K-Jet) would not be great, based on the cross section area of >parts of it. You know what happens when a carburettor induction manifold is >badly designed? Fuel separation, uneven combustion etc (carbie V8s now), I don't understand what the carb discussion has to do with K-Jet. Maybe I missed something. >sump dilution, bla, bla, bla. You have seen the crap that collects inside >K-Jet's air / fuel reg. with normal driving? Not much if you have an adequate filter. Most of the gunk comes from the engine side. What is left under the fuel-metering unit, which is the space I think you're talking about, is in a low-velocity region - - it's a stagnant area. The main corrosion problem which I understand would arise is with the pivot and base of the control plunger. One could reduce the stagnant volume by drawing air in from that side, instead of the sensor-plate end. i.e the air would run in the direction of the sensor-plate lever. That would be an "unusual" arrangement. >How / where will air / fuel reg be mounted on boat? Far enough away (perhaps separated by a thermal barrier) from the engine and a "long way" from the air inlet. One should try to get it as close as possible to the inlet tracts - the total duct length of meter to manifold is less than one metre in most cars. >At what temp will it operate at? Hopefully, about 25 to 30 C. That's the desired inlet air temperature. The metering unit may in part be 10 degrees hotter but the cooling effect of fuel and air flow should mean that it's somewhat cooler than the surrounding environment. >Under the bonnet, it operates at under bonnet temp, less what ever cooling >effect may come from fresh air, depending on where air is tapped. Remote The "air box" with metering unit often have provision for accepting pre-heated air. >mounting on Clair's motor would be an interesting exercise. Check operating Don't know. Haven't seen the engine, nor the engine compartment. >temp of box in the car, then on the boat. This will play a part as to how >quick the thing will rust out. ... How hot doesn the engine compartment get on a boat? Over 120C? >I stand by what I have said, no amount of 250,000 trouble free km over the >road will convince me that K-Jet will function perfectly on water on it's >second trip out. >Try this : >Pull the air cleaner off your Merc. Jam the throttle at 2,500 RPM. Stand It's a VW. It doesn't have K-Jet. >back with a kero cleaning gun with the pick up hose in a 205 litre drum of >salt water. Direct the spray toward the engine and run the experiment for >half an hour. Shut everything down and come back in two weeks. Pull the air >valve box apart and inspect all parts. Why on earth would I want to destroy an engine like that? Experience tells me that you can't run an engine for any length of time without an airfilter _on the road_ without severe damage. That's what I told the SBG Rally team when they brought their cars into WA in 1997. They ignored me and the engine failed to start on the second-last day because they had NO compression. The thing had been re-bored by the dust - total competitive running time at that point was about 3 hours. They had filters in the following year. >The LUCAS throttle bodies on the other hand consist of a butterfly and shaft >and ram tubes if one has opted for tuned length runners. A rev and a squirt >with CRC down each throat would be the sum total of post service required on >our Lucas system, but I think with K-Jet user would always find himself / >herself reaching for his / her tool box. I wouldn't run K-Jet without adequate filtering. If the Lucas system copes with it, then good. >My previous comments were all about reliability on the water = safety. Now all you have to do is to stop them running out of fuel, or getting the fuel contaminated. >The pic is not a Lucas system, it is Autronic. The turbos are >Garrett ball bearing type, which by the way reduces back pressure >for a given boost on the same compressor. This should be a factor >to consider, with the on going discussion on turbo charging and >water injection. And you have nothing to say about the low mounting of the alternator? :-) - -- Real Name: Bernd Felsche Email: nospam.bernie@xxx.au http://www.perth.dialix.com.au/~bernie - Private HP - ---------------------------------------------------------------------------- To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes) in the body of a message (not the subject) to majordomo@xxx.org ------------------------------ End of DIY_EFI Digest V5 #114 ***************************** 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".