From owner-diy_efi Thu Dec 15 04:24:33 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA00524; Thu, 15 Dec 94 04:24:33 GMT Received: from localhost.eng.ohio-state.edu by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA00519; Wed, 14 Dec 94 23:24:30 -0500 Message-Id: <9412150424.AA00519@coulomb.eng.ohio-state.edu> To: diy_efi Subject: admin: new archive structure Date: Wed, 14 Dec 94 23:24:30 -0500 From: John S Gwynne Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI -------- I've broken up the previous excessively large single archive file into small manageable files. archive_num_*: archive files of about 500 lines (26k bytes). archive_date_index: file showing the start date of each of the above files. archive_current: the most recent/current postings. John S Gwynne Gwynne.1@osu.edu _______________________________________________________________________________ T h e O h i o - S t a t e U n i v e r s i t y ElectroScience Laboratory, 1320 Kinnear Road, Columbus, Ohio 43212, USA Telephone: (614) 292-7981 * Fax: (614) 292-7292 ------------------------------------------------------------------------------- From owner-diy_efi Thu Dec 15 15:11:28 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA01436; Thu, 15 Dec 94 15:11:28 GMT Received: from wotan.compaq.com by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA01431; Thu, 15 Dec 94 10:11:25 -0500 Received: from twisto.eng.hou.compaq.com by wotan.compaq.com with smtp (Smail3.1.28.1 #12) id m0rIHq0-000vIoC; Thu, 15 Dec 94 09:11 CST Received: from bangate.compaq.com by twisto.eng.hou.compaq.com with smtp (Smail3.1.28.1 #10) id m0rIHpu-000uIkC; Thu, 15 Dec 94 09:11 CST Message-Id: Received: by bangate.compaq.com with VINES ; Thu, 15 Dec 94 09:10:43 CST Date: Thu, 15 Dec 94 09:09:50 CST From: Steve=Ravet%Prj=Eng%PCPD=Hou@bangate.compaq.com Subject: re: admin: new archive structure To: diy_efi Cc: Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI John S Gwynne Wrote: | | | -------- | | I've broken up the previous excessively large single | archive file into small manageable files. Can these be retrieved via anonymous ftp? Or is mailer request the only way? --steve From owner-diy_efi Thu Dec 15 15:13:59 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA01450; Thu, 15 Dec 94 15:13:59 GMT Received: from spectre.uunet.ca by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA01445; Thu, 15 Dec 94 10:13:50 -0500 Received: from gateway.prior.com ([142.77.252.4]) by spectre.uunet.ca with SMTP id <33759>; Thu, 15 Dec 1994 10:12:47 -0500 Received: by gateway.prior.com (4.1/SMI-4.1) id AA16293; Thu, 15 Dec 94 10:08:34 EST Received: from odin.prior.com(192.139.238.33) by gateway.prior.com via smap (V1.3) id sma016291; Thu Dec 15 10:08:11 1994 Received: from ivan.prior.com by odin.prior.com (4.1/SMI-4.1) id AA01002; Thu, 15 Dec 94 10:06:19 EST Received: by ivan.prior.com (931110.SGI/930416.SGI) for @odin.prior.com:DIY_EFI@coulomb.eng.ohio-state.edu id AA16426; Thu, 15 Dec 94 10:18:52 -0500 Date: Thu, 15 Dec 1994 10:18:52 -0500 From: MSargent@gallium.com (Michael F. Sargent) Message-Id: <9412151518.AA16426@ivan.prior.com> To: DIY_EFI Subject: Re: admin: new archive structure Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI Thanks you! Thank you! Thank you! Mike +--------------------------------------------------------------------------+ | Michael F. Sargent | Net: msargent@gallium.com | Phone: 1(613)721-0902 | | Gallium Software Inc.| | FAX: 1(613)721-1278 | +--------------------------------------------------------------------------+ From owner-diy_efi Thu Dec 15 15:42:29 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA03209; Thu, 15 Dec 94 15:42:29 GMT Received: from localhost.eng.ohio-state.edu by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA03204; Thu, 15 Dec 94 10:42:26 -0500 Message-Id: <9412151542.AA03204@coulomb.eng.ohio-state.edu> To: DIY_EFI Subject: Re: admin: new archive structure In-Reply-To: Your message of "Thu, 15 Dec 94 09:09:50 CST." Date: Thu, 15 Dec 94 10:42:26 -0500 From: John S Gwynne Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI -------- In message , you write: | Can these be retrieved via anonymous ftp? Or is mailer request the only way? Email is the only way to do it from Coulomb (I don't really want to open this machine up to anonymous ftp...). If someone volunteers an ftp site for this purpose, I'm sure we could work something out. John S Gwynne Gwynne.1@osu.edu _______________________________________________________________________________ T h e O h i o - S t a t e U n i v e r s i t y ElectroScience Laboratory, 1320 Kinnear Road, Columbus, Ohio 43212, USA Telephone: (614) 292-7981 * Fax: (614) 292-7292 ------------------------------------------------------------------------------- From owner-diy_efi Fri Dec 16 13:27:30 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA11462; Fri, 16 Dec 94 13:27:30 GMT Received: from knuth.mtsu.edu by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA11457; Fri, 16 Dec 94 08:27:26 -0500 Received: by knuth.mtsu.edu (Smail3.1.28.1 #21) id m0rIceV-000CvzC; Fri, 16 Dec 94 07:24 CST Message-Id: From: lusky@knuth.mtsu.edu (Jonathan R. Lusky) Subject: Re: admin: new archive structure To: DIY_EFI Date: Fri, 16 Dec 1994 07:24:55 -0600 (CST) In-Reply-To: <9412151542.AA03204@coulomb.eng.ohio-state.edu> from "John S Gwynne" at Dec 15, 94 10:42:26 am X-Mailer: ELM [version 2.4 PL24alpha3] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 780 Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI John S Gwynne writes: > > -------- > > In message , you write: > > | Can these be retrieved via anonymous ftp? Or is mailer request the only way? > > Email is the only way to do it from Coulomb (I don't > really want to open this machine up to anonymous > ftp...). If someone volunteers an ftp site for this > purpose, I'm sure we could work something out. Once I get a new drive I could probably put stuff up at work... sometime after the 1st of the year. -- Jonathan R. Lusky lusky@knuth.mtsu.edu http://frank.mtsu.edu/~lusky/ (615) 726-8700 ------------------------------------- ------------------------------ 68 Camaro Convertible - 350 / TH350 \_/ 80 Toyota Celica - 20R / 5spd From owner-diy_efi Tue Dec 20 10:19:43 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA29467; Tue, 20 Dec 94 10:19:43 GMT Received: from hermes.intel.com by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA29462; Tue, 20 Dec 94 05:19:39 -0500 Received: from PTD.intel.com by hermes.intel.com (5.65/10.0i); Tue, 20 Dec 94 02:07:35 -0800 Date: Tue, 20 Dec 94 02:17:05 PST From: MBOSSARD@PTD.intel.com Message-Id: <9412201017.utk2304@PTD.intel.com> X-To: HERMES::"DIY_EFI@coulomb.eng.ohio-state.edu" Subject: Fuel Injector Positioning To: DIY_EFI Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI In fitting an intake manifold for injectors, what angle and position of the injector yields the best results? I'm guessing that the injector should point towards the valve. How far should the injector portrude into the runner? MJB From owner-diy_efi Tue Dec 20 22:50:40 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA02931; Tue, 20 Dec 94 22:50:40 GMT Received: from shiva.trl.OZ.AU by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA02926; Tue, 20 Dec 94 17:50:35 -0500 Received: by shiva.trl.OZ.AU id AA04530 (5.65c/IDA-1.4.4 for DIY_EFI@coulomb.eng.ohio-state.edu); Wed, 21 Dec 1994 09:50:27 +1100 From: Craig Pugsley Message-Id: <199412202250.AA04530@shiva.trl.OZ.AU> Subject: Injector supply voltage & positioning. To: DIY_EFI Date: Wed, 21 Dec 1994 09:50:26 +1100 (EST) X-Mailer: ELM [version 2.4 PL20] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 1027 Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI Hi there, I was discussing EFI in general the other day with a mechanic freind and couldn't convince him that it is best to run the injectors from full battery voltage, and use a compensation in the opening time of the injector for lower voltages. He thought it would be more logical to run the injectors from a fixed voltage source (eg 8 volts), then you wouldn't have to worry about compensating. I said it's comparable to using the starter motor at 8 volts - if you've got the power on hand, why not use it? Does this seem like a reasonable reply to his question? Also, the person who asked about injector positioning, I'd suggest selecting a location where the spray least collides with the side walls (eg on the 'elbow' of the manifold bend, pointing into the port). I supposed technically speaking you'd want it where the most turbulance is, however you're not easily going to find that. Take a look at some workshop manuals on EFI cars, that should give a few ideas for your specific situation. Merry Xmas, Craig. From owner-diy_efi Wed Dec 21 14:04:41 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA01138; Wed, 21 Dec 94 14:04:41 GMT Received: from geni10.arl.mil by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA01133; Wed, 21 Dec 94 09:04:33 -0500 Received: by lamp0.arl.army.mil (5.65/DEC-Ultrix/4.3) id AA17179; Wed, 21 Dec 1994 09:04:22 -0500 Date: Wed, 21 Dec 1994 09:04:22 -0500 Message-Id: <9412211404.AA17179@lamp0.arl.army.mil> X-Sender: faustini@geni10.arl.army.mil Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: DIY_EFI From: faustini@lamp0.arl.army.mil (Lou Faustini) Subject: Re: Injector supply voltage & positioning. X-Mailer: Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI >Hi there, > >I was discussing EFI in general the other day with a mechanic freind and >couldn't convince him that it is best to run the injectors from full >battery voltage, and use a compensation in the opening time of the >injector for lower voltages. > >He thought it would be more logical to run the injectors from a fixed >voltage source (eg 8 volts), then you wouldn't have to worry about >compensating. I said it's comparable to using the starter motor at 8 >volts - if you've got the power on hand, why not use it? Does this seem >like a reasonable reply to his question? > Aren't injectors a binary-type thing? ... Either they are on, or they are off right?. I thought there was some mechanical hysteresys built in. I assume if you were to drive them at very low voltages you might find a point where they are in a semi-open state, but I assume that that voltage would probly be around 5 or less volts. I know that Toyota corp actually puts a 2-ohm resistor in serise with their injectors. They are also low-side swithced. Question.. What fuel pressure do you folks recomend running the injectors at. I heard that the Ford-type injectors, like the ones used on the Mustang V-8, run at about 40+psi. Is this true? That sounds like a real problem for the hobyst who would like to use Trak-Auto fuel line. I know that my Holley setup runs 15psi. That is a little more reasonable to work/play with. ------ Lou Faustini From owner-diy_efi Wed Dec 21 14:58:38 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA01222; Wed, 21 Dec 94 14:58:38 GMT Received: from wotan.compaq.com by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA01217; Wed, 21 Dec 94 09:58:36 -0500 Received: from twisto.eng.hou.compaq.com by wotan.compaq.com with smtp (Smail3.1.28.1 #12) id m0rKSUr-000vIxC; Wed, 21 Dec 94 08:58 CST Received: from bangate.compaq.com by twisto.eng.hou.compaq.com with smtp (Smail3.1.28.1 #10) id m0rKSUk-000uJmC; Wed, 21 Dec 94 08:58 CST Message-Id: Received: by bangate.compaq.com with VINES ; Wed, 21 Dec 94 08:58:27 CST Date: Wed, 21 Dec 94 08:51:24 CST From: Steve=Ravet%Prj=Eng%PCPD=Hou@bangate.compaq.com Subject: re: Re: Injector supply voltage & positioning. To: diy_efi Cc: Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI faustini@lamp0.arl.army.mil (Lou Faustini) Wrote: | Aren't injectors a binary-type thing? ... Either they are on, or they | are off right?. I thought there was some mechanical hysteresys built in. | I assume if you were to drive them at very low voltages you might find a | point where they are in a semi-open state, but I assume that that voltage | would probly be around 5 or less volts. I know that Toyota corp actually | puts a 2-ohm resistor in serise with their injectors. They are also | low-side swithced. They are, except for turn on and turn-off time. At high and low duty cycles the turn on and turn off times can be significant. A higher voltage will open the injector faster. The two ohm resistor is for current limiting. The impedance of the injector coil drops exponentially while it is on, ie the instant you apply voltage, the impedance is near infinite (or at least real high). It drops quickly to whatever the resistance of the coil wire is, which is usually not much. The coil will draw too much current by itself if left on for too long, hence the resistor to limit current. A better solution would be a transistorized constant current driver. | | Question.. What fuel pressure do you folks recomend running the | injectors at. I heard that the Ford-type injectors, like the ones used | on the Mustang V-8, run at about 40+psi. Is this true? That sounds like | a real problem for the hobyst who would like to use Trak-Auto fuel line. | I know that my Holley setup runs 15psi. That is a little more reasonable | to work/play with. | ------ Lou Faustini --steve From owner-diy_efi Wed Dec 21 15:20:37 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA01361; Wed, 21 Dec 94 15:20:37 GMT Received: from spectre.uunet.ca by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA01356; Wed, 21 Dec 94 10:20:29 -0500 Received: from gateway.prior.com ([142.77.252.4]) by spectre.uunet.ca with SMTP id <34347>; Wed, 21 Dec 1994 10:19:21 -0500 Received: by gateway.prior.com (4.1/SMI-4.1) id AA24627; Wed, 21 Dec 94 10:15:04 EST Received: from odin.prior.com(192.139.238.33) by gateway.prior.com via smap (V1.3) id sma024623; Wed Dec 21 10:14:39 1994 Received: from ivan.prior.com by odin.prior.com (4.1/SMI-4.1) id AA01232; Wed, 21 Dec 94 10:12:04 EST Received: by ivan.prior.com (931110.SGI/930416.SGI) for @odin.prior.com:DIY_EFI@coulomb.eng.ohio-state.edu id AA00434; Wed, 21 Dec 94 10:25:30 -0500 Date: Wed, 21 Dec 1994 10:25:30 -0500 From: MSargent@gallium.com (Michael F. Sargent) Message-Id: <9412211525.AA00434@ivan.prior.com> To: DIY_EFI Subject: Re: Injector supply voltage & positioning. Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI The best reason I've heard for running an injector at full supply voltage (which will probably be around 14 volts when running) is that the higher voltage allows the injector to open faster, allowing better control when short pulse widths are required (idle, and light load cruising). Mike +--------------------------------------------------------------------------+ | Michael F. Sargent | Net: msargent@gallium.com | Phone: 1(613)721-0902 | | Gallium Software Inc.| | FAX: 1(613)721-1278 | +--------------------------------------------------------------------------+ From owner-diy_efi Wed Dec 21 15:27:08 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA01412; Wed, 21 Dec 94 15:27:08 GMT Received: from spectre.uunet.ca by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA01407; Wed, 21 Dec 94 10:27:05 -0500 Received: from gateway.prior.com ([142.77.252.4]) by spectre.uunet.ca with SMTP id <34774>; Wed, 21 Dec 1994 10:26:03 -0500 Received: by gateway.prior.com (4.1/SMI-4.1) id AA24647; Wed, 21 Dec 94 10:21:34 EST Received: from odin.prior.com(192.139.238.33) by gateway.prior.com via smap (V1.3) id sma024645; Wed Dec 21 10:21:13 1994 Received: from ivan.prior.com by odin.prior.com (4.1/SMI-4.1) id AA01249; Wed, 21 Dec 94 10:18:39 EST Received: by ivan.prior.com (931110.SGI/930416.SGI) for @odin.prior.com:DIY_EFI@coulomb.eng.ohio-state.edu id AA00476; Wed, 21 Dec 94 10:32:00 -0500 Date: Wed, 21 Dec 1994 10:32:00 -0500 From: MSargent@gallium.com (Michael F. Sargent) Message-Id: <9412211532.AA00476@ivan.prior.com> To: DIY_EFI Subject: Re: Injector supply voltage & positioning. Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI > Question.. What fuel pressure do you folks recomend running the > injectors at. I heard that the Ford-type injectors, like the ones used > on the Mustang V-8, run at about 40+psi. Is this true? That sounds like > a real problem for the hobyst who would like to use Trak-Auto fuel line. > I know that my Holley setup runs 15psi. That is a little more reasonable > to work/play with. The high pressure is used to ensure good fuel atomization at all engine speeds. Most (if not all) EFI systems run more than 30 PSI fuel pressure. Many use a rising rate pressure regulator to raise the fuel pressure as the manifold pressure increases (vacuum drops). This provides the same pressure differential across the injector. A few systems use a progressive fuel regulator which increases the fuel pressure at a rate faster than the manifold pressure increases. This provides more fuel flow at WOT, while still allowing the use of smaller injectors for better idle fuel control. If fuel line is your only consideration, spend $10 and get better fuel line. Mike +--------------------------------------------------------------------------+ | Michael F. Sargent | Net: msargent@gallium.com | Phone: 1(613)721-0902 | | Gallium Software Inc.| | FAX: 1(613)721-1278 | +--------------------------------------------------------------------------+ From owner-diy_efi Wed Dec 21 16:00:45 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA01626; Wed, 21 Dec 94 16:00:45 GMT Received: from merlin.nando.net by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA01621; Wed, 21 Dec 94 11:00:42 -0500 Received: by merlin.nando.net (4.1/davel-nando/june94) id AA11408; Wed, 21 Dec 94 10:59:22 EST Date: Wed, 21 Dec 1994 10:59:21 -0500 (EST) From: David Cooley To: Lou Faustini Cc: DIY_EFI Subject: Re: Injector supply voltage & positioning. In-Reply-To: <9412211404.AA17179@lamp0.arl.army.mil> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI On Wed, 21 Dec 1994, Lou Faustini wrote: > > Aren't injectors a binary-type thing? ... Either they are on, or they > are off right?. I thought there was some mechanical hysteresys built in. > I assume if you were to drive them at very low voltages you might find a > point where they are in a semi-open state, but I assume that that voltage > would probly be around 5 or less volts. I know that Toyota corp actually > puts a 2-ohm resistor in serise with their injectors. They are also > low-side swithced. True, they are in a sense binary, but the pull-in time increases as voltage drops. As pressure rises, pull in time increases also. > > Question.. What fuel pressure do you folks recomend running the > injectors at. I heard that the Ford-type injectors, like the ones used > on the Mustang V-8, run at about 40+psi. Is this true? That sounds like > a real problem for the hobyst who would like to use Trak-Auto fuel line. > I know that my Holley setup runs 15psi. That is a little more reasonable > to work/play with. > > Lou, The port FI injectors do run at a higher pressure. Most often they run at 38-45psabove manifold pressure. The regulator on a PFI system will hold this differential by referencing fuel pressure to manifold press. Typically with approx 20" vacuum, fuel pressure is 30-35 psi. In a turbo or supercharged application, fuel pressure will increase by 1 psi for every psi boost pressure. The reason for the higher PSI in a PFI application is this: The injector is only open a short time and must deliver a highly precise amount ofd fuel. The throttle body systems have much larger orifices and are typicaly open longer than the PFI injectors. The PFI system must have a good pressure to atomize the fuel as it doesn't have a lot of distance to travel to the cylinder... Anything still liquid just washes oil off the cylinder walls and is detrimental to performance and emissions. Later, Dave Cooley cooldave@nando.net From owner-diy_efi Wed Dec 21 16:14:50 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA01665; Wed, 21 Dec 94 16:14:50 GMT Received: from nrcnet.nrc.ca by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA01660; Wed, 21 Dec 94 11:14:47 -0500 Received: from DECNET-MAIL by NRCNET.NRC.CA (PMDF #12639) id <01HKWIWYFVPC8WW17U@NRCNET.NRC.CA>; Wed, 21 Dec 1994 11:08 EST Date: Wed, 21 Dec 1994 11:08 EST From: Peter Orban Subject: Re: Re: Injector supply voltage & positioning. To: DIY_EFI Message-Id: <01HKWIWYFVPC8WW17U@NRCNET.NRC.CA> X-Envelope-To: DIY_EFI@coulomb.eng.ohio-state.edu X-Vms-To: NRCNET::IN%"DIY_EFI@coulomb.eng.ohio-state.edu" Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI >They are, except for turn on and turn-off time. At high and low duty cycles >the turn on and turn off times can be significant. A higher voltage will open >the injector faster. The two ohm resistor is for current limiting. The >impedance of the injector coil drops exponentially while it is on, ie the >instant you apply voltage, the impedance is near infinite (or at least real >high). It drops quickly to whatever the resistance of the coil wire is, which >is usually not much. The coil will draw too much current by itself if left on >for too long, hence the resistor to limit current. A better solution would be >a transistorized constant current driver. > I belive that several companies make injector drivers, I remember receiving some stuff on that. Those circuits should address all those concerns. Try TI and SGS. Peter -- Peter Orban National Research Council of Canada Internet: peter.orban@nrc.ca From owner-diy_efi Thu Dec 22 03:47:24 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA04545; Thu, 22 Dec 94 03:47:24 GMT Received: from merlin.nando.net by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA04540; Wed, 21 Dec 94 22:47:20 -0500 Received: by merlin.nando.net (4.1/davel-nando/june94) id AA20902; Wed, 21 Dec 94 22:45:59 EST Date: Wed, 21 Dec 1994 22:45:59 -0500 (EST) From: David Cooley To: Peter Orban Cc: DIY_EFI Subject: Re: Re: Injector supply voltage & positioning. In-Reply-To: <01HKWIWYFVPC8WW17U@NRCNET.NRC.CA> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI On Wed, 21 Dec 1994, Peter Orban wrote: > > I belive that several companies make injector drivers, I remember > receiving some stuff on that. Those circuits should address all those > concerns. Try TI and SGS. > > Peter > -- > Peter Orban > National Research Council of Canada > Internet: peter.orban@nrc.ca > > > Peter, Harris has a full line of automotive ECM products. They are in the harris Intelligent Power Devices book. Later, Dave Cooley cooldave@nando.net From owner-diy_efi Thu Dec 22 05:04:35 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA04652; Thu, 22 Dec 94 05:04:35 GMT Received: from eigen.ee.ualberta.ca by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA04647; Thu, 22 Dec 94 00:04:32 -0500 Message-Id: <9412220504.AA04647@coulomb.eng.ohio-state.edu> Received: by eigen.ee.ualberta.ca (1.37.109.4/15.6) id AA29656; Wed, 21 Dec 94 22:04:29 -0700 From: Dale Ulan Subject: Re: Injector supply voltage & positioning. To: DIY_EFI Date: Wed, 21 Dec 94 22:04:28 MST In-Reply-To: ; from "David Cooley" at Dec 21, 94 10:59 am Mailer: Elm [revision: 70.85] Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI > On Wed, 21 Dec 1994, Lou Faustini wrote: > > a PFI application is this: The injector is only open a short time and > must deliver a highly precise amount ofd fuel. The throttle body > systems have much larger orifices and are typicaly open longer than the ____ yes ____________ **nope*** > PFI injectors. The PFI system must have a good pressure to atomize the > fuel as it doesn't have a lot of distance to travel to the cylinder... > Anything still liquid just washes oil off the cylinder walls and is > detrimental to performance and emissions. Best performance seems to occur when airflow is minimal in the intake port. I don't know why, but timed injection systems appear to avoid injecting while the intake is open. This is probably to minimize wall wetting due to reversion. TBI injectors are open for *shorter* than PFI injectors. PFI injectors have up to 720 degrees of crank rotation to complete their injection. With this amount of time, a low flow rate injector can be used, for very precise flow control. The high fuel pressure is more to do with the fact that port injectors run hotter than TBI systems, so the high fuel pressure is needed to prevent vapor formation in the fuel injectors. PFI injectors do not have the appropriate structure to vent vapors formed within.... all vapor must exit through the output port. TBI systems can run a lower pressure because they generally have a very open design, and bottom-up fuel feed. This helps control vapor venting. Lower pressure means one thing only: it's cheaper. The regulator is cheaper, as are gasket materials used everywhere. And most importantly, the fuel pump is cheaper. Take a look at the TBI paper presented by GM in 1980. Also, in a V-8 2-injector TBI, each injector must open four times in 720 degrees, or 180 degrees maximum opening time (minus closing/opening times). Thus, the TBI systems are actually open for shorter periods of time. -Dale From owner-diy_efi Thu Dec 22 07:01:26 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA04800; Thu, 22 Dec 94 07:01:26 GMT Received: from kaiwan.kaiwan.com by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA04795; Thu, 22 Dec 94 02:01:23 -0500 Received: from kaiwan009.kaiwan.com (1300@kaiwan009.kaiwan.com [192.215.30.9]) by kaiwan.kaiwan.com (8.6.9/8.6.5) with ESMTP id XAA10758 for ; Wed, 21 Dec 1994 23:01:20 -0800 *** KAIWAN Internet Access *** Received: (from patriot@localhost) by kaiwan009.kaiwan.com (8.6.9/8.6.9) id XAA15982; Wed, 21 Dec 1994 23:01:22 -0800 *** KAIWAN Internet Access *** Date: Wed, 21 Dec 1994 23:01:20 -0800 (PST) From: Nate To: DIY_EFI Subject: Re: Re: Injector supply voltage & positioning. In-Reply-To: <01HKWIWYFVPC8WW17U@NRCNET.NRC.CA> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI I was thinking... (ouch! that hurts!) -------------------!_________________________ _________________________ -------------------! ^ ^ ^ Injector Tube, heated by exhaust Now, the computer monitors the heat of the tube, so we inject liquid till the thing heats up, then after it gets hot enough (we have a program that slowley changes the injection amount as the pipe heats up) we are then injecting pure (almost) vapors. I have a 3 Cyl "Sprint" that gets 45 Mpg most of the time, so this would make it get 70 right??? Just a idea, I might just try it, but if I run it by you guys first, maybe I can save some of the trial and error. What I would do is take a spare air cleaner I have and mount this to it Horizontaly, and have the exhaust just shoot out under the hood while I try to see what works. What is a good cheap injector and pressure pump? need something for experiment type prices (like free from nice guy at junk yard?). If this works, and I make a million.... wait if this works they will be trying to shoot me wont they? maybe we should quit now???? From owner-diy_efi Thu Dec 22 18:09:47 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA06051; Thu, 22 Dec 94 18:09:47 GMT Received: from CyberSpace.CyberAuto.Com by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA06046; Thu, 22 Dec 94 13:09:40 -0500 Received: (from cmyer@localhost) by cyberspace.cyberauto.com (8.6.9/8.6.9) id NAA29651 for DIY_EFI@coulomb.eng.ohio-state.edu; Thu, 22 Dec 1994 13:00:46 -0500 Date: Thu, 22 Dec 1994 13:00:46 -0500 From: Chris Myer Message-Id: <199412221800.NAA29651@cyberspace.cyberauto.com> To: DIY_EFI Subject: Hello Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI Just wanted to make my presence known here on the list, and possibly inject (ooh, bad joke) some useful information. I didn't know if we had access to any backposts, so pardon me if I am repeating stuff that was said before I joined the list. First, I am not an EFI buff. I have more knowledge of "old school" techniques for making a car run fast. However, I do have a strong knowledge of engines in addition to my EE background. Second, is anyone familiar with AEM (Advanced Engine Management) out of LA, Cali? These guys have a TON of knowledge about fuel and engine management systems. They have developed a Throttle-Body very similar to the DCOE Weber Carb, with an injector in each intake manifold. They sell these, along with a host of engine management goodies from Motec, Electromotive, and others. If this isn't something that has already been discussed, I can provide more information. Third, I work for Harris. I am awaiting word on a transfer to the DSP applications group of their Semiconductor Sector. This group is a sister organization to the Automotive Controls group mentioned a few posts ago. _If_ my transfer is approved, I can serve as a point of contact for Harris databooks, etc. I am not too sure about part samples, but that is also a possiblity. As far as the DSP and Data Acquisition group, I would have basically a open agenda to develop new applications in this area. Obviously, I would love to use Harris DSP/DAQ parts to do new work in the EFI area. I'll let you know if this dream becomes a reality. Hope everybody has an excellent Holiday Season, and I look forward to learning (and teaching?) some new things in this group. Chris (Nifty .sig being designed...) From owner-diy_efi Thu Dec 22 20:19:38 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA06439; Thu, 22 Dec 94 20:19:38 GMT Received: from geni10.arl.mil by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA06434; Thu, 22 Dec 94 15:19:34 -0500 Received: by lamp0.arl.army.mil (5.65/DEC-Ultrix/4.3) id AA20281; Thu, 22 Dec 1994 15:19:33 -0500 Date: Thu, 22 Dec 1994 15:19:33 -0500 Message-Id: <9412222019.AA20281@lamp0.arl.army.mil> X-Sender: faustini@geni10.arl.army.mil Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: DIY_EFI From: faustini@lamp0.arl.army.mil (Lou Faustini) Subject: Re: Hello X-Mailer: Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI >Just wanted to make my presence known here on the list, and possibly >inject (ooh, bad joke) some useful information. I didn't know if we >had access to any backposts, so pardon me if I am repeating stuff >that was said before I joined the list. > >. >Hope everybody has an excellent Holiday Season, and I look forward to >learning (and teaching?) some new things in this group. > Welcome to the group. I am currently working on a replacement for the Holley Pro-jection ANALOG control computer. All of this goes into a 1980 Mercury Capri with a 302cI ballanced and blueprinted motor. It runs well now, but I have big plans for improvement. Anyway... Welcome to the group. ----- Lou Faustini From owner-diy_efi Mon Dec 26 16:03:29 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA13665; Mon, 26 Dec 94 16:03:29 GMT Received: from gw1.att.com by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA13660; Mon, 26 Dec 94 11:03:27 -0500 Received: from uscbu.ih.att.com by ig1.att.att.com id AA15939; Mon, 26 Dec 94 11:01:21 EST Received: by uscbu.ih.att.com (4.1/EMS-1.1.1 SunOS) id AA06486; Mon, 26 Dec 94 10:01:36 CST Received: from usgp1.ih.att.com by uscbu.ih.att.com (4.1/EMS-1.1.1 SunOS) id AA06429; Mon, 26 Dec 94 10:00:48 CST Received: by usgp1.ih.att.com (5.0/EMS-1.1 Sol2) id AA14835; Mon, 26 Dec 1994 10:04:17 +0600 Date: Mon, 26 Dec 1994 10:04:17 +0600 Message-Id: <9412261604.AA14835@usgp1.ih.att.com> From: bohdan@uscbu.ih.att.com (Bohdan L Bodnar) To: DIY_EFI Subject: Re: Injector supply voltage & positioning. Content-Type: text Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI There are two types of fuel injectors in use: saturated switch driven and peak-and-hold. Saturated switch injectors are either high-impedance (about 16 ohms dc) or low impedance (about 3 ohms dc). Peak-and-hold injectors are low impedance. Low impedance saturated switch injectors are always driven via resistance wire so as to limit current. Peak-and-hold injectors typically are driven at full supply voltage (less voltage drop across driving transistor) for a short time (e.g., in GM's throttle body systems, this time is 1.5 ms) and then power is drastically cut. The idea behind peak-and-hold injectors is the same as in pull-in and hold-in windings on starter solenoids: it takes more power to overcome static friction than to overcome dynamic friction. If one 'scopes a peak-and-hold injector, one will see two distinct back-emf "kicks" across the injector. I've never seen peak-and-hold injectors used for anything other than TBI systems. Saturated switch injectors are merely driven via a saturated switch ("class C amplifier" for you EE types) -- either a power MOSFET or an NPN switching transistor. Hope this helps... Regards, Bohdan Bodnar From owner-diy_efi Tue Dec 27 03:26:39 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA14317; Tue, 27 Dec 94 03:26:39 GMT Received: from knuth.mtsu.edu by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA14311; Mon, 26 Dec 94 22:26:36 -0500 Received: by knuth.mtsu.edu (Smail3.1.28.1 #21) id m0rMSYI-000CunC; Mon, 26 Dec 94 21:26 CST Message-Id: From: lusky@knuth.mtsu.edu (Jonathan R. Lusky) Subject: Re: Injector supply voltage & positioning. To: DIY_EFI Date: Mon, 26 Dec 1994 21:26:22 -0600 (CST) In-Reply-To: <9412261604.AA14835@usgp1.ih.att.com> from "Bohdan L Bodnar" at Dec 26, 94 10:04:17 am X-Mailer: ELM [version 2.4 PL24alpha3] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 1089 Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI Bohdan L Bodnar writes: > > Peak-and-hold injectors typically are driven at full supply voltage (less > voltage drop across driving transistor) for a short time (e.g., in GM's > throttle body systems, this time is 1.5 ms) and then power is drastically cut. > The idea behind peak-and-hold injectors is the same as in pull-in and hold-in > windings on starter solenoids: it takes more power to overcome static > friction than to overcome dynamic friction. If one 'scopes a peak-and-hold > injector, one will see two distinct back-emf "kicks" across the injector. > I've never seen peak-and-hold injectors used for anything other than TBI > systems. I don't know what else uses them, but I know the Buick GN and the Flex-fuel Chevy Corsicas use peak-and-hold injectors. Most racing applications use peak-and-hold too. -- Jonathan R. Lusky lusky@knuth.mtsu.edu http://frank.mtsu.edu/~lusky/ (615) 726-8700 ------------------------------------- ------------------------------ 68 Camaro Convertible - 350 / TH350 \_/ 80 Toyota Celica - 20R / 5spd From owner-diy_efi Thu Dec 29 12:54:46 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA29453; Thu, 29 Dec 94 12:54:46 GMT Received: from nrcnet.nrc.ca by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA29448; Thu, 29 Dec 94 07:54:42 -0500 Received: from DECNET-MAIL by NRCNET.NRC.CA (PMDF #12639) id <01HL7I7NKJZ48WVZR4@NRCNET.NRC.CA>; Thu, 29 Dec 1994 07:47 EST Date: Thu, 29 Dec 1994 07:47 EST From: Peter Orban Subject: VW Digifant ECU To: DIY_EFI Message-Id: <01HL7I7NKJZ48WVZR4@NRCNET.NRC.CA> X-Envelope-To: DIY_EFI@coulomb.eng.ohio-state.edu X-Vms-To: NRCNET::IN%"DIY_EFI@coulomb.eng.ohio-state.edu" Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI Merry Christmas and a Happy New Year to everyone! Has anyone dug into the Digifant FI, and its potential for modification, of VWs, 88-92 Golfs and Jettas? Currently there are no aftermarket chips available for this ECU. The architecture is a dual processor one: An intel 8039 for the fuel control, that chip has its code in a 2764 EPROM, and has a TI ADC 0809 attached to it. The other processor is a Motorola 6805 variant for the ignition control. The processor itself is marked SC 80984, and is EPROM programmable. Has anyone heard about this particular chip? Any information and discussion on the above would be much appreciated! Thanks, Peter -- Peter Orban National Research Council of Canada Internet: peter.orban@nrc.ca From owner-diy_efi Thu Dec 29 13:58:29 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA29521; Thu, 29 Dec 94 13:58:29 GMT Received: from merlin.nando.net by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA29516; Thu, 29 Dec 94 08:58:25 -0500 Received: by merlin.nando.net (4.1/davel-nando/june94) id AA17976; Thu, 29 Dec 94 08:56:58 EST Date: Thu, 29 Dec 1994 08:56:58 -0500 (EST) From: David Cooley To: Peter Orban Cc: DIY_EFI Subject: Re: VW Digifant ECU In-Reply-To: <01HL7I7NKJZ48WVZR4@NRCNET.NRC.CA> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI On Thu, 29 Dec 1994, Peter Orban wrote: > Merry Christmas and a Happy New Year to everyone! > > Has anyone dug into the Digifant FI, and its potential for modification, > of VWs, 88-92 Golfs and Jettas? Currently there are no aftermarket chips > available for this ECU. > The architecture is a dual processor one: An intel 8039 for the fuel > control, that chip has its code in a 2764 EPROM, and has a TI ADC 0809 > attached to it. The other processor is a Motorola 6805 variant for the > ignition control. The processor itself is marked SC 80984, and is EPROM > programmable. Has anyone heard about this particular chip? > Any information and discussion on the above would be much appreciated! > > Thanks, Peter > -- > Peter Orban > National Research Council of Canada > Internet: peter.orban@nrc.ca > > > > Peter, There is one company that says they have a chip for your application, but I would be kind of leery of them.. Superchips Inc. They have chips for: VW 1.8 L 16V, 2.0L 8&16V, VW VR6, and VW G60. Now the owner of this company admitted to fraud a while back on the mitsubishi eclipse. Someone asked him why he didn't change the eprom program (they read the chip before they sent it to him) in the ECM. He supplied a 5.00 aquarium air valve to use as a bleeder to increase boost, put a superchips sticker on top of the eprom, and charged 300 dollars. The rest of his chips may be the same or they may not. Later, Dave From owner-diy_efi Thu Dec 29 14:55:25 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA29610; Thu, 29 Dec 94 14:55:25 GMT Received: from geni10.arl.mil by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA29605; Thu, 29 Dec 94 09:55:12 -0500 Received: by lamp0.arl.army.mil (5.65/DEC-Ultrix/4.3) id AA25704; Thu, 29 Dec 1994 09:55:03 -0500 Date: Thu, 29 Dec 1994 09:55:03 -0500 Message-Id: <9412291455.AA25704@lamp0.arl.army.mil> X-Sender: faustini@geni10.arl.army.mil Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: DIY_EFI From: faustini@lamp0.arl.army.mil (Lou Faustini) Subject: Re: VW Digifant ECU Cc: ORBAN@nrcamt.iamt.nrc.ca X-Mailer: Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI >Merry Christmas and a Happy New Year to everyone! > >Has anyone dug into the Digifant FI, and its potential for modification, >of VWs, 88-92 Golfs and Jettas? Currently there are no aftermarket chips >available for this ECU. >The architecture is a dual processor one: An intel 8039 for the fuel >control, that chip has its code in a 2764 EPROM, and has a TI ADC 0809 >attached to it. The other processor is a Motorola 6805 variant for the >ignition control. The processor itself is marked SC 80984, and is EPROM >programmable. Has anyone heard about this particular chip? >Any information and discussion on the above would be much appreciated! > Peter, I have not dug into that FI system, but I can tell you a little about the CPU's they are using. I -think- that I remember the Intel 8039 as a real small micro-controler. Its real funny to program, if I remember corrrectly, its adress space is limited to 1k chunks. the upper adress lines are bank-switched through software. (sounds like an Intel product eh?) That means its a real pain to write lengthy code on. The factory probly kept the software very simple on this chip. They kinda had to. I bet the code isn't much moore than a look up table. The fuel injection map is probly resides in that externam eprom. I also think the 8039 has about 1k of internal EPROM. Is the EPROM socketed? If so, pull it out and read it into you're PC. I will look up the docs on the 8039 for you, and let you know where the CPU starts out of reset. (I -think- its at $0000 ) If you hand-disasemble the code at the reset-vector location, and it appears to make sense, then you are on to something. If that chip truly contains a simple program to do look up it wont be too hard to completly disassemble the code, and figure out how their fuel map works.. Hope this helped.. ------ Lou Faustini From owner-diy_efi Thu Dec 29 18:46:23 1994 Received: by coulomb.eng.ohio-state.edu (920330.SGI/920502.SGI) id AA00593; Thu, 29 Dec 94 18:46:23 GMT Received: from us.dynix.com by coulomb.eng.ohio-state.edu via SMTP (920330.SGI/920502.SGI) for /usr/local/mail/majordomo-1.92/wrapper resend -p bulk -M 10000 -l Diy_Efi -f Diy_Efi-Owner -h coulomb.eng.ohio-state.edu -s -r DIY_EFI diy_efi-outgoing id AA00588; Thu, 29 Dec 94 13:46:08 -0500 Received: from cpu.us.dynix.com by dnxjcit.us.dynix.com with SMTP id AA27943 (5.65c/IDA-1.4.4 for ); Thu, 29 Dec 1994 11:54:40 -0700 Received: by cpu.us.dynix.com (AIX 3.2/UCB 5.64/4.03) id AA50731; Thu, 29 Dec 1994 11:45:10 -0700 Date: Thu, 29 Dec 1994 11:41:48 -700 (MST) From: Jim Conforti Subject: Re: VW Digifant ECU To: Peter Orban Cc: DIY_EFI In-Reply-To: <01HL7I7NKJZ48WVZR4@NRCNET.NRC.CA> Message-Id: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-diy_efi Precedence: bulk Reply-To: DIY_EFI On Thu, 29 Dec 1994, Peter Orban wrote: > The architecture is a dual processor one: An intel 8039 for the fuel > control, that chip has its code in a 2764 EPROM, and has a TI ADC 0809 > attached to it. The other processor is a Motorola 6805 variant for the > ignition control. The processor itself is marked SC 80984, and is EPROM > programmable. Has anyone heard about this particular chip? > Any information and discussion on the above would be much appreciated! Peter .. not to speak for the group, but if you can get us access to: 1) the 8039 specs 2) The binary image of that 2764 EPROM .. We might be able to do you some good .. My partner and I have gotten a REAL good knowledge of the BOSCH Motronic systems, and I'm sure we'd be willing to tackle the Digifant .. especially if someone has an 8039 disassembler ;) (The latest Motronic was also dual proc. and Rod had to WRITE a bloody disassembler for one of the processors .. he's a serious hacker!) Jim Conforti