DIY_EFI Digest Tuesday, June 15 1999 Volume 04 : Number 359 In this issue: Re: o2 sensor Re: Dual fuel PFI rails.... RE: Subject: Not diy_efi....how to disable a computer carb Re: Dual fuel PFI rails.... Re: o2 sensor Re: [Fwd: diy_efi_www] RE: o2 sensor Re: o2 sensor RE: Subject: Not diy_efi....how to disable a computer carb Re: Dual fuel PFI rails.... Locating maps in an ECU Re: o2 sensor Re: Dual fuel PFI rails.... Re: ECU files Re: Dual fuel PFI rails.... Re: ECU files Re: Subject: Not diy_efi....how to disable a computer carb Re: o2 sensor Re: Dual fuel PFI rails.... Re: o2 sensor Re: Subject: Not diy_efi....how to disable a computer carb Subject: Not diy_efi....how to disable a computer carb or put in tbi Re: Dual fuel PFI rails.... Re: Dual fuel PFI rails.... FS: 1227748 WTB: 1227747 Re: Dual fuel PFI rails.... Re: Dual fuel PFI rails LCD thing Re: Dual fuel PFI rails.... dis and timming See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Tue, 15 Jun 1999 19:45:47 +1000 From: "Geffro" Subject: Re: o2 sensor Nigel wrote >Get hold of a copy of the data sheet of the LM3914 off the web. It shows >you how to connect it up in various ways. > Got an address please ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ Geoff Richards mha@xxx.com My learning curve seems to start way over my head ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ------------------------------ Date: Tue, 15 Jun 1999 06:05:22 -0400 From: Shannen Durphey Subject: Re: Dual fuel PFI rails.... Barry Tisdale wrote: > > Something got lost in translation here, I think. (BTW, was using my wife's account for the original message - I'm back home again). > > DUAL fuel; I'd need *two* parallel holes drilled the length of the bar. Cross-drilling the two longitidinal holes where the injectors will be placed, plugging the access opening to the outside of the rail. This results in two parallel holes, connected by cross-holes where the injectors will go. Drill the injector feeds into this hole, between the long parallel holes, so's one injector can be fed by either of the two 'logs'. One log would carry pump gas, the other, the fuel of your choice, probably avgas. Two separate circuits, tanks, pumps, regualtors, etc. It would take about 0.2 sec for the fuel transition to occur; the volume of 'old' fuel to be flushed out of the common volume before the injector saw 'new' fuel. > > Only problem is the drilling of two parallel holes in, say, a 1" x 3/4" bar, about 9" long - say, 5/16" holes & cross-drillings. Is this do-able?? > > Assembling out of tubing & welding all the fittings would be tedious, at best, and surely beyond my skills. If I had the 9" bars drilled, I could probably take it from there. > > Technically, any comments? Surely, this isn't the first time anyone has thought of this; anybody done something similar? Probably ideal is a manifold w/ 2 injectors per intake port, but this is *really* beyond my capabilities. > > Sincere thanks for any feedback - Barry You'll want to use something to shut off the fuel system that isn't in use, to prevent dilution and the transferring of fuel from one tank to the other. Once you've done this, there's no reason you can't run a single rail system. To reduce the time required to switch fuels, tee the lines directly before and after the rails, and install the isolation valves there. To reduce the amount of tubing used, tee the lines back at the tank and install the isolation valves there. Design the system so hot soak conditions don't put the injectors under extreme pressures and cause leakage. Look through the archives, Greg Hermann has described an ideal fuel rail design. I'd try to set it up so isolation system failure doesn't mean a dead car. One set of valves is normally open, one set is normally closed. Shannen ------------------------------ Date: Mon, 14 Jun 1999 15:26:24 -0500 From: Don.F.Broadus@xxx.com Subject: RE: Subject: Not diy_efi....how to disable a computer carb I would still check the M/C solenoid. The solenoid controls the primary metering rods buy moving them up and down at a duty cycle controlled by the ECM and its inputs. My 82 T/A did the same thing your olds is doing , running extremely rich. The Q-Jet runs rich because a spring on the metering rods pulls them completely out of the primary jets. The M/C solenoid when energized pushes the rods down into the jets leaning out the mixture. The only way to bypass the M/C solenoid is to convert back to the vac type metering rods if this is possible . Fix the carb or go to a non electronic Q-Jet and non computer HEI, of course the ECM now has nothing to do. Don > -----Original Message----- > From: ken mayer [SMTP:mayerk@xxx.net] > Sent: Sunday, June 13, 1999 11:56 AM > To: diy_efi@xxx.edu > Cc: ARoss10661@xxx.com > Subject: Subject: Not diy_efi....how to disable a computer carb > > > > Date: Sat, 12 Jun 1999 21:35:03 EDT > > From: ARoss10661@xxx.com > > > > I need help. The computer carb on my 83 Olds 98 (307) has decided to > send so > > much fuel into the mixture that it pumps gas fumes out the tailpipe. Is > > > there a way to disable it safely??? Any help is appreciated > > If the carb float is original, it has probably absorbed fuel and gained > weight. That's what typically causes flooding on these cars. Replace the > float. Be careful handling the TPS as its easily broken. > > Ken > :-) ------------------------------ Date: Tue, 15 Jun 1999 08:01:19 est From: "Charles Brooks" Subject: Re: Dual fuel PFI rails.... Why not "T" into the supply line before the fuel rail and use the existing fuel rail? You could use two solenoid valves, one on the supply line and one on the return line so that you don't mix the two fuels you're trying to run. It would take a bit longer for the alternate fuel to get to all the injectors but it would be MUCH simpler to plumb. Charles Brooks - ---------- Original Message ---------------------------------- From: Barry Tisdale Reply-To: diy_efi@xxx.edu Date: Mon, 14 Jun 1999 21:02:05 -0400 >Something got lost in translation here, I think. (BTW, was using my wife's account for the original message - I'm back home again). DUAL fuel; I'd need *two* parallel holes drilled the length of the bar. Cross-drilling the two longitidinal holes where the injectors will be placed, plugging the access opening to the outside of the rail. This results in two parallel holes, connected by cross-holes where the injectors will go. Drill the injector feeds into this hole, between the long parallel holes, so's one injector can be fed by either of the two 'logs'. One log would carry pump gas, the other, the fuel of your choice, probably avgas. Two separate circuits, tanks, pumps, regualtors, etc. It would take about 0.2 sec for the fuel transition to occur; the volume of 'old' fuel to be flushed out of the common volume before the injector saw 'new' fuel. Only problem is the drilling of two parallel holes in, say, a 1" x 3/4" bar, about 9" long - say, 5/16" holes & cross-drillings. Is this do-able?? Assembling out of tubing & welding all the fittings would be tedious, at best, and surely beyond my skills. If I had the 9" bars drilled, I could probably take it from there. Technically, any comments? Surely, this isn't the first time anyone has thought of this; anybody done something similar? Probably ideal is a manifold w/ 2 injectors per intake port, but this is *really* beyond my capabilities. Sincere thanks for any feedback - Barry ------------------------------ Date: Tue, 15 Jun 1999 21:34:45 +1000 From: "Geffro" Subject: Re: o2 sensor Roseanna rbt1@xxx.com wrote AND - >you can set the "window" of observed values to anywhere, any resolution, by >choosing the proper values for REF HI and REF LO on the chip. How ? Cheers Geoff Richards ------------------------------ Date: Tue, 15 Jun 1999 21:35:22 +1000 From: "Geffro" Subject: Re: [Fwd: diy_efi_www] Steve Steve.Ravet@xxx.com wrote Had a question about starting an IRC channel for diy_efi or gmecm. Any >interest? > Was gonna suggest that myself the other day but didn't cause I only got questions :) BUT I would LOVE to see it happen Cheers Geoff Richards ------------------------------ Date: Tue, 15 Jun 1999 13:39:14 +0100 From: "Robertson, Nigel" Subject: RE: o2 sensor http://www.national.com and enter lm3914 in the search box then follow it from there. Nigel > -----Original Message----- > From: Geffro [SMTP:geoffsue@xxx.au] > Sent: 15 June 1999 10:46 > To: diy_efi > Subject: Re: o2 sensor > > > > > > > Nigel wrote > > >Get hold of a copy of the data sheet of the LM3914 off the web. It shows > >you how to connect it up in various ways. > > > Got an address please > > ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ > Geoff Richards > mha@xxx.com > My learning curve seems to start way over my head > ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ > > ------------------------------ Date: Tue, 15 Jun 1999 08:56:03 -0400 From: "Peter D. Hipson" Subject: Re: o2 sensor Uh, huh! There are search engines for this, you know... Check out http://www.euronet.nl/users/fo_elmo/afdisplay.htm for an interesting implementation. BTW, Lycos will give you the mfgr's page where you can D/L a PDF file with the data sheet. At 07:45 PM 6/15/99 +1000, you wrote: > > > > > >Nigel wrote > >>Get hold of a copy of the data sheet of the LM3914 off the web. It shows >>you how to connect it up in various ways. >> >Got an address please > >~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ >Geoff Richards >mha@xxx.com >My learning curve seems to start way over my head >~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ > > > > > Thanks, Peter Hipson (founder, NEHOG) 1995 White NA Hummer Wagon ------------------------------ Date: Tue, 15 Jun 1999 06:16:07 -0700 From: neilaura@xxx.com Subject: RE: Subject: Not diy_efi....how to disable a computer carb At 03:26 PM 6/14/99 -0500, you wrote: >I would still check the M/C solenoid. The solenoid controls the primary >metering rods buy moving them up and down at a duty cycle >controlled by the ECM and its inputs. My 82 T/A did the same thing your olds >is doing , running extremely rich. The Q-Jet runs rich because a spring on >the metering rods pulls them completely out of the primary jets. The M/C >solenoid when energized pushes the rods down into the jets leaning out the >mixture. The only way to bypass the M/C solenoid is to convert back to the >vac type metering rods if this is possible . Fix the carb or go to a non >electronic Q-Jet and non computer HEI, of course the ECM now has nothing to >do. >Don That's only part of it Don. When the solenoid pulls the needles down and closes off the jets it, also opens an air bleed valve to further lean out the mixture. Possible options are. Physically hold the needles half way in/out of the jets. Or use a 555 as a base for a generating a 50% square wave, and disconnect the engine check light. Neil ------------------------------ Date: Tue, 15 Jun 1999 08:48:10 -0400 From: Barry Tisdale Subject: Re: Dual fuel PFI rails.... Fredrick - Looks like you advise me on another project! The video work went by the board for two months while I tracked down a 'lousy running' problem that turned out to be a plugged cat converter. How's your quad LCD project going? Anyhow, what I envision isn't 2 injectors per cylinder, but two rails feeding a single injector (already in place) w/ two different fuels. Would have to fab a complete manifold for my Sy to mount two injectors per cylinder, *definitely* something I don't want to get into! Machining the six needed Al blocks wouldn't be hard, but all the fittings might be. Each block (holding one injector) would have two fuel inlets & 2 outlets. That's four connections per block, a total of 24 connections to make for a V6. Probably isn't physical space for such a thing, and a leak *somewhere* seems inevitable; plumber's nightmare! I'm still not sure I'm getting my idea across. Lets say you have three pipe Tees, of a size the injector will fit into. Place the injector into the upright leg of one Tee; then, take the other two tees and connect their base leg (upright leg) into the two ends of the crossleg of the tee containing the injector. You now have two tees feeding one, which then feeds the sole injector for one cylinder. Common volume would be too large to allow rapid switching of fuels w/ this arrangement, but that's the idea. Question comes down to: can two parallel holes of 5/16" dia. be drilled in a 1" x 3/4" block, 9" long? Guess I just need to try it; Al stock available locally, I have 9" metal lathe, just need a *long* 5/16" drill. Guess the question *really* is, can *I* do it; probably very do-able by a pro! This letter turned out to be "thinking out loud" - guess I'll just have to tool up & try it; will fill those long winter months coming soon....... I just thought someone, somewhere, must have done this & could offer tips & advice. Thanks - Barry ------------------------------ Date: Tue, 15 Jun 1999 09:29:01 est From: "Charles Brooks" Subject: Locating maps in an ECU I was looking over some of the stuff on the site and I've got an idea. If I simply plot EVERYTHING in the ECU I should be able to see all of the 2D/3D maps right? They should look like ramps or some sort of regular waveform. I'm not sure if that's right or not but I'll go ahead and try it and let you guys know what I get. Yesterday I was unable to find a serial cable long enough to get to the Data I/O PROM reader we have here at work, but I have one now :) I'll dump the PROM at lunch and import the data to Excel and see what I can see. Oh yeah, I zipped the Astrovan stuff and I'll send it out tonight to everyone who has requested it. Charles Brooks ------------------------------ Date: Tue, 15 Jun 1999 23:39:25 +1000 From: Peter Gargano Subject: Re: o2 sensor National Semiconductor is a good guess for a lot of LM numbered devices... http://www.national.com/search/search.cgi/main?keywords=lm3914 Geoff Richards wrote: > Got an address please ? - -- Peter Gargano ------------------------------ Date: Mon, 14 Jun 1999 16:51:56 -0600 From: "Kevin Yachimec" Subject: Re: Dual fuel PFI rails.... Frederic Breitwieser wrote: > ntisdale wrote: > > > Was just thinking a dual fuel setup, via various methods. Dual injectors > > would be ideal, but would be a lot of work which I'm not equipped to do > > (maybe now's the time to learn....). Proposed vehicle is 4.3l Syclone. > > Making an additional fuel rail is really not that complex. The key is > making it simple enough to machine out using fairly common tools. > The following page outlines the construction of a fuel rail out of square 3/4" stock steel: http://www.sdsefi.com/tech.html It has good pictures of the construction. The page also shows you the construction of an intake manifold for a Mazda RX-7. Kevin Yachimec Cybertech Automation Inc. Edmonton Alberta Canada keviny@xxx.ca ------------------------------ Date: Tue, 15 Jun 1999 10:05:03 est From: "Charles Brooks" Subject: Re: ECU files Thanks for the info Dave. I'm going to try to import the PROM image into Excel and plot the whole thing. Hopefully I'll see at least some of the tables as repeating shapes. Come to think of it, CarPROM screen shots look kind of like that. The Arizona Speed and Marine site has a couple screen shots of CarPROM interpretations of PROM images. It looks like a simple graph of the entire PROM image. Does anybody on the list have CarPROM? Is that how it works? Charles Brooks - ---------- Original Message ---------------------------------- From: "David A. Cooley" Reply-To: diy_efi@xxx.edu Date: Mon, 14 Jun 1999 21:23:04 -0400 >At 09:08 PM 6/14/99 -0400, you wrote: >Thanks Steve, I found it :) > >OK, assuming I'm able to identify a series of blocks as a table (Big >assumption :) How do I find out what type of table it is? i.e. VE fuel, >acceleration enrichment, spark advance etc... ? > Usually by trial and error... modify a table and try it, monitor it with Diacom or similar and see what changed. >It looks like the data points in Promedit are scaled 0-255, is that for all >tables or do some tables use a different scale? Would be totally wrong to >assume that all the data points consist of three places? i.e. 001-255 (Or >whatever the scale is) All values in the chip (raw) go 0-255 (00-FF hex). some are scaled to be - -127 to +127... very few actually mean what the number is raw in the chip ie: a timing value in the chip may be AC hex, but would mean 35 in actual timing degrees... Each table has a formula associated with it, and each ECM/PCM and cal may have different formulas for the same type of table. Best bet is look at the .ecu file that comes with promedit and see how that chip is laid out... look at the tables, and look at them in the raw chip image. Most have a pattern that is recognizable. ------------------------------ Date: Tue, 15 Jun 1999 07:36:59 -0700 (PDT) From: Squash Subject: Re: Dual fuel PFI rails.... - --- Barry Tisdale wrote: > Question comes down to: can two parallel holes of > 5/16" dia. be drilled in a 1" x 3/4" block, 9" long? > Guess I just need to try it; Al stock available > locally, I have 9" metal lathe, just need a *long* > 5/16" drill. Guess the question *really* is, can > *I* do it; probably very do-able by a pro! 9" long? If you know someone who has a 4-jaw chuck for your lathe or someone else's it should be a cake-job. If you use rectangular AL, you can also drill it in a drill press w/o fancy brackets (for the injector holes). But wouldn't it be the same concept if you just switched in the alternative fuel where the fuel feeds into the rails? Or are you going for a mixture of the two? > This letter turned out to be "thinking out loud" - > guess I'll just have to tool up & try it; will fill > those long winter months coming soon....... I just > thought someone, somewhere, must have done this & > could offer tips & advice. Long winter months coming soon? You must live in wisconsin. We go from constuction right into winter. Squash _________________________________________________________ Do You Yahoo!? Get your free @xxx.com ------------------------------ Date: Tue, 15 Jun 1999 07:41:44 -0700 (PDT) From: Squash Subject: Re: ECU files - --- Charles Brooks wrote: > Thanks for the info Dave. I'm going to try to import > the PROM image into Excel and plot the whole thing. > Hopefully I'll see at least some of the tables as > repeating shapes. Come to think of it, CarPROM > screen shots look kind of like that. The Arizona > Speed and Marine site has a couple screen shots of > CarPROM interpretations of PROM images. It looks > like a simple graph of the entire PROM image. Does > anybody on the list have CarPROM? Is that how it > works? I got a peice of software that someone from this list wrote (or referred me to). It is a free-ware windoze program that allows you to specify a start and end address for a table (or the whole bin) and then graph them. I can't remember the name or URL, but i'll look it up for ya. SqUaSh _________________________________________________________ Do You Yahoo!? Get your free @xxx.com ------------------------------ Date: Tue, 15 Jun 1999 11:10:53 -0400 From: Shannen Durphey Subject: Re: Subject: Not diy_efi....how to disable a computer carb neilaura@xxx.com wrote: > > At 03:26 PM 6/14/99 -0500, you wrote: > >I would still check the M/C solenoid. The solenoid controls the primary > >metering rods buy moving them up and down at a duty cycle > >controlled by the ECM and its inputs. My 82 T/A did the same thing your olds > >is doing , running extremely rich. The Q-Jet runs rich because a spring on > >the metering rods pulls them completely out of the primary jets. The M/C > >solenoid when energized pushes the rods down into the jets leaning out the > >mixture. The only way to bypass the M/C solenoid is to convert back to the > >vac type metering rods if this is possible . Fix the carb or go to a non > >electronic Q-Jet and non computer HEI, of course the ECM now has nothing to > >do. > >Don > > That's only part of it Don. > When the solenoid pulls the needles down and closes off the jets it, also > opens an air bleed valve to further lean out the mixture. > Possible options are. Physically hold the needles half way in/out of the > jets. Or use a 555 as a base for a generating a 50% square wave, and > disconnect the engine check light. > > Neil Been there, done that. Physically balancing the two works great at idle, but lousy on the road. There's no deceleration enleanment, no richening of mixture under load. I suspect the reason the carb goes to full rich is to give some semblance of driveability, especially in the underpowered, highway geared barges they were first used on. I've run these carbs with the m/c solenoid disconnected, leaning the rich stop some. Don't hope to pass an emissions test though, especially if it requires off idle testing. Also, make sure the AIR pump isn't pumping O2 into the manifolds or cat when you're running rich, else you'll end up with a nice warm glow from the exhaust system. Feedback carbs take some real skill, IMO, and the time you invest in them could easily be replaced with time in a junkyard pulling parts for a tbi swap. Bruce P can tell ya stories about those carbs, I've just started working on them in the last few years. Shannen ------------------------------ Date: Tue, 15 Jun 1999 11:14:59 est From: "Charles Brooks" Subject: Re: o2 sensor http://www.national.com/pf/LM/LM3914.html Geoff, here's a link to one of National Semiconductor's LM3914 pages. National also has a tech support address that you can send questions about products to. They've been very helpfull with some of my past projects. Charles Brooks - ---------- Original Message ---------------------------------- From: "Geffro" Reply-To: diy_efi@xxx.edu Date: Tue, 15 Jun 1999 21:34:45 +1000 > Roseanna rbt1@xxx.com wrote AND - >you can set the "window" of observed values to anywhere, any resolution, by >choosing the proper values for REF HI and REF LO on the chip. How ? Cheers Geoff Richards ------------------------------ Date: Tue, 15 Jun 1999 10:45:08 -0400 From: Barry Tisdale Subject: Re: Dual fuel PFI rails.... Hey, thanks for the reply! What I had in mind is very like what you suggest, with solenoid valves to block the return line of the fuel *not* in use; one NO (normally open), one NC. Both switched to follow their appropriate pumps; analagous to ORing them. Reason for the *two* rails is to minize the switchover time; the more volume common to the two fuel circuits, the greater the time to purge the 'old' fuel and the longer the time before the injector sees the 'new' fuel. I'd like the system to be transparent, switching at, say, 1 psi of boost to the higher octane fuel. With two rails of 5/16" diameter, 1/4" common bores feeding the injector, switchover time should be 0.3 seconds or better. Seems to be just a mechanical problem, like what to make the assembly out of & how to fit it into the space available, same mounting setup, etc. I'll check the archives as you suggested. Thanks for the advice; certainly appreciate it! - Barry At 06:05 AM 6/15/99 -0400, Shannen Durphey wrote: >You'll want to use something to shut off the fuel system that isn't in >use, to prevent dilution and the transferring of fuel from one tank to >the other. Once you've done this, there's no reason you can't run a >single rail system. To reduce the time required to switch fuels, tee >the lines directly before and after the rails, and install the >isolation valves there. To reduce the amount of tubing used, tee the >lines back at the tank and install the isolation valves there. Design >the system so hot soak conditions don't put the injectors under >extreme pressures and cause leakage. Look through the archives, Greg >Hermann has described an ideal fuel rail design. I'd try to set it up >so isolation system failure doesn't mean a dead car. One set of >valves is normally open, one set is normally closed. >Shannen > > ------------------------------ Date: Tue, 15 Jun 1999 10:56:46 -0400 From: Barry Tisdale Subject: Re: o2 sensor Feed them thru a voltage dividing pot (10-12 turn is good) to whatever voltages you want. If you set REF lo to 0.9v and REF hi to 1.0v, you resolve the range between them. Chip contains a divider that makes 10 steps between the hi & lo volts. At 09:34 PM 6/15/99 +1000, Geffro wrote: >Roseanna rbt1@xxx.com wrote > >AND - >>you can set the "window" of observed values to anywhere, any resolution, by >>choosing the proper values for REF HI and REF LO on the chip. > >How ? > >Cheers >Geoff Richards > > > > > > > > > ------------------------------ Date: Tue, 15 Jun 1999 12:01:23 EDT From: ARoss10661@xxx.com Subject: Re: Subject: Not diy_efi....how to disable a computer carb Thanks for all the info guys, I did some cking yesterday and found a HUGE vacuum leak in a line connecter (3/16 hole). The car had been partially de-smogged by a incompetent mechanic some time in the past and it is a vacuum line nightmare im cking now to see how it runs with the vacuum lk sealed. BTW love the 555 squarewave idea. Al ------------------------------ Date: Tue, 15 Jun 1999 12:03:29 EDT From: ARoss10661@xxx.com Subject: Subject: Not diy_efi....how to disable a computer carb or put in tbi In a message dated 6/15/99 10:13:48 AM Central Daylight Time, shannen@xxx.com writes: << Been there, done that. Physically balancing the two works great at idle, but lousy on the road. There's no deceleration enleanment, no richening of mixture under load. I suspect the reason the carb goes to full rich is to give some semblance of driveability, especially in the underpowered, highway geared barges they were first used on. I've run these carbs with the m/c solenoid disconnected, leaning the rich stop some. Don't hope to pass an emissions test though, especially if it requires off idle testing. Also, make sure the AIR pump isn't pumping O2 into the manifolds or cat when you're running rich, else you'll end up with a nice warm glow from the exhaust system. Feedback carbs take some real skill, IMO, and the time you invest in them could easily be replaced with time in a junkyard pulling parts for a tbi swap. Bruce P can tell ya stories about those carbs, I've just started working on them in the last few years. Shannen >> OK hers a question for everyone who thinks a tbi swap might be worth the trouble like off of a 305 chevy?? Al ------------------------------ Date: Tue, 15 Jun 1999 12:24:52 -0400 From: Frederic Breitwieser Subject: Re: Dual fuel PFI rails.... Howdy Barry, > Looks like you advise me on another project! The video work went by the board for two months while I tracked down a 'lousy running' problem that turned out to be a plugged cat converter. Ouch,that sucks! I killed yet another junkyard 318 in my truck, though I did paint it recently, and it came out acceptable for a backyard paintjob. http://www.xephic.dynip.com/dodge/dodge.html >How's your quad LCD project going? Its not... I pushed it aside for later efforts... too much "garage" stuff to do while its hot out. I have the following projects going: 1. weld mid-engine chassis together. 2. install 383-->431 twinturbo stroker into truck. 3. install EEC-IV or GM730 ecm into truck upon 383 stroker. 4. install new suspension on my Lincoln (higher priority) 5. install dually rear onto truck. 6. fabricate dually fenders for truck (and install). 7. rewire truck. 8. continue experiments with 12V in PC switching power supply. I have a 70 continental to sand, derust, and paint, as well as a early 60's suicide door continental to sand, derust, weld, paint, and repair pretty much everything :) Feel free to come visit and pitch in :) The 4-LCD display thing is kinda on the back burner. Been trying to find an ISA card that does the same thing, making it much simpler than building a video card from scratch. Slowly, as time permits. > Anyhow, what I envision isn't 2 injectors per cylinder, but two rails feeding a single injector (already in place) w/ two different fuels. Would have to fab a complete manifold for my Sy to mount two injectors per cylinder, *definitely* something I don't want to get into! Well, the only concern I have with two fuel rails and one injector, is what happens if the line pressure on one fuel deteriorates? Then the second fuel will push back through the other fuel rail and end up in the tank, reducing overall fuel pressure, and mixing the fuels. Having two injectors per cylinder, irregardless of the fuel choices, ensures a failsafe mechanism whereas you can limp home using the other set of fuel rail/inejctors if you have some neat programming in the ECM :) > Machining the six needed Al blocks wouldn't be hard, but all the fittings might be. Each block (holding one injector) would have two fuel inlets & 2 outlets. That's four connections per block, a total of 24 connections to make for a V6. Probably isn't physical space for such a thing, and a leak *somewhere* seems inevitable; plumber's nightmare! On the Buick V6, we had three injectors per cylinder, two for gas and one for an 80/20 mix of isopropol and distilled water, all running in parallel. We had 10-12" of space on the runners on the intake, so there was room for all of this "stuff". >injector for one cylinder. Common volume would be too large to allow rapid switching of fuels w/ this arrangement, but that's the idea. Two rails, one gas, one alcohol, with a "T" between, feeding on injector. Got it. This allows cross-flow of the fuels if the pressure drops, and you'll mix. two injectors I think are a better solution, but I haven't experimented with your idea, so I can't say for sure. You'd need some kind of check valve either at the "T" joints or maybe back at the start of the fuel rail where the fuel lines feed into, thus preventing mix and contamination. Also realize by mixing before the injector, you have much less control of the ratio between regular fuel versus special fuel. Just some random thoughts. >need a *long* 5/16" drill. Guess the question *really* is, can *I* do it; probably very do-able by a pro! I made my own fuel rails. if I can do it, anyone can :) - -- Frederic Breitwieser Bridgeport CT 06606 1993 Supercharged Lincoln Continental 1989 HWMMV w/turbocharged 500cid Caddy 1975 Dodge D200 Club Cab soon to have 431 stroker + turbos 2000 (I hope) Buick GTP (Mid-Engined Sports Car) ------------------------------ Date: Tue, 15 Jun 1999 12:30:28 -0400 From: Frederic Breitwieser Subject: Re: Dual fuel PFI rails.... Howdy Barry, > Looks like you advise me on another project! The video work went by the board for two months while I tracked down a 'lousy running' problem that turned out to be a plugged cat converter. Ouch,that sucks! I killed yet another junkyard 318 in my truck, though I did paint it recently, and it came out acceptable for a backyard paintjob. http://www.xephic.dynip.com/dodge/dodge.html >How's your quad LCD project going? Its not... I pushed it aside for later efforts... too much "garage" stuff to do while its hot out. I have the following projects going: 1. weld mid-engine chassis together. 2. install 383-->431 twinturbo stroker into truck. 3. install EEC-IV or GM730 ecm into truck upon 383 stroker. 4. install new suspension on my Lincoln (higher priority) 5. install dually rear onto truck. 6. fabricate dually fenders for truck (and install). 7. rewire truck. 8. continue experiments with 12V in PC switching power supply. I have a 70 continental to sand, derust, and paint, as well as a early 60's suicide door continental to sand, derust, weld, paint, and repair pretty much everything :) Feel free to come visit and pitch in :) The 4-LCD display thing is kinda on the back burner. Been trying to find an ISA card that does the same thing, making it much simpler than building a video card from scratch. Slowly, as time permits. > Anyhow, what I envision isn't 2 injectors per cylinder, but two rails feeding a single injector (already in place) w/ two different fuels. Would have to fab a complete manifold for my Sy to mount two injectors per cylinder, *definitely* something I don't want to get into! Well, the only concern I have with two fuel rails and one injector, is what happens if the line pressure on one fuel deteriorates? Then the second fuel will push back through the other fuel rail and end up in the tank, reducing overall fuel pressure, and mixing the fuels. Having two injectors per cylinder, irregardless of the fuel choices, ensures a failsafe mechanism whereas you can limp home using the other set of fuel rail/inejctors if you have some neat programming in the ECM :) > Machining the six needed Al blocks wouldn't be hard, but all the fittings might be. Each block (holding one injector) would have two fuel inlets & 2 outlets. That's four connections per block, a total of 24 connections to make for a V6. Probably isn't physical space for such a thing, and a leak *somewhere* seems inevitable; plumber's nightmare! On the Buick V6, we had three injectors per cylinder, two for gas and one for an 80/20 mix of isopropol and distilled water, all running in parallel. We had 10-12" of space on the runners on the intake, so there was room for all of this "stuff". >injector for one cylinder. Common volume would be too large to allow rapid switching of fuels w/ this arrangement, but that's the idea. Two rails, one gas, one alcohol, with a "T" between, feeding on injector. Got it. This allows cross-flow of the fuels if the pressure drops, and you'll mix. two injectors I think are a better solution, but I haven't experimented with your idea, so I can't say for sure. You'd need some kind of check valve either at the "T" joints or maybe back at the start of the fuel rail where the fuel lines feed into, thus preventing mix and contamination. Also realize by mixing before the injector, you have much less control of the ratio between regular fuel versus special fuel. Just some random thoughts. >need a *long* 5/16" drill. Guess the question *really* is, can *I* do it; probably very do-able by a pro! I made my own fuel rails. if I can do it, anyone can :) - -- Frederic Breitwieser Bridgeport CT 06606 1993 Supercharged Lincoln Continental 1989 HWMMV w/turbocharged 500cid Caddy 1975 Dodge D200 Club Cab soon to have 431 stroker + turbos 2000 (I hope) Buick GTP (Mid-Engined Sports Car) ------------------------------ Date: Tue, 15 Jun 1999 11:39:46 -0500 From: steve ravet Subject: FS: 1227748 WTB: 1227747 Subject says it. I have a 1227748 ECM for sale, remanufactured. Comes complete with everything I've been able to learn about it (ha ha ha). This is a P4 ECM, 8192 baud ALDL that has a bare PROM socket instead of a MEMCAL. It was in Fieros, Sunbirds, probably some others. I'd like to trade for a 747 ECM if anyone has one to offer, or I'll buy your spare 747. - --steve - -- Steve Ravet steve.ravet@xxx.com Advanced Risc Machines, Inc. www.arm.com ------------------------------ Date: Tue, 15 Jun 1999 12:51:35 -0400 From: "SPECTRO COATING CORP." Subject: Re: Dual fuel PFI rails.... Anyhow, what I envision isn't 2 injectors per cylinder, but two rails feeding a single injector (already in place) w/ two different fuels. Would have to fab a complete manifold for my Sy to mount two injectors per cylinder, *definitely* something I don't want to get into! (snip) Shannen aluded to the single rail 2 valve but perhaps it wasn't clear, perhaps i can offer a better explanation. First - drilling the parallel holes rails is indeed possible as you - however - 5/16'' id will be marginal for size with the flows i suspect you'll need. Second your going to get some drill drift at that length. If you have some one that gundrills nearby then they could easily do it, but i think that you don't want to proceed in this manner. Here's why - when you are running regular fuel - say tank 1 you've filled your dual fuel setup with the regular fuel - as you shift to race fuel (tank 2) you'll have to purge the entire system - including the tank 1 fuel rail before you get a true shot of the good stuff. However (as Shannen said) if you were to run a single rail (fed from the normal tank and from the race tank but isolated by valves at inlet and outlet you could operate it this way - poor art Tank 1 ----check valve 1 -----rail------ valve 2 ----- return to tank 1 / \ tank 2 ---- check valve 3 ---/ \--- valve 4 return to tank 2 say your running on tank 1 as normal driving (valves 1 & 2 are open and 3 & 4 are shut) and want to switch to the good stuff then start the pump on tank 2 and shut tank 1 pump off (make before break switch or timed relay) this allows the race fuel to purge that pump gas into tank one. after so many seconds (purge complete) then open valve 4 and shut valve 2 - this prevents "wasting" your expensive race gas by dumping it into the pump gas tank to shift back open valve 2 shut 4 and then start pump 1 and stop pump 2 i think this is pretty much how the dual fuel tank pickup trucks shift there fuel supply - someone here can probably confirm that just my $.02 worth - Jason ------------------------------ Date: Tue, 15 Jun 1999 12:53:29 -0400 (EDT) From: "Clive Apps Techno-Logicals 416 510 0020" Subject: Re: Dual fuel PFI rails LCD thing check out matrixorbital.com Clive ------------------------------ Date: Tue, 15 Jun 1999 10:13:16 -0700 (PDT) From: Squash Subject: Re: Dual fuel PFI rails.... - --- Frederic Breitwieser wrote: > Having two injectors per cylinder, irregardless of > the fuel choices, > ensures a failsafe mechanism whereas you can limp > home using the other > set of fuel rail/inejctors if you have some neat > programming in the > ECM :) I agree. You could also mount 2 larger injectors into the TBI area of your manifold, possibly. Not the best, but still would work. SQuaSH _________________________________________________________ Do You Yahoo!? Get your free @xxx.com ------------------------------ Date: Tue, 15 Jun 1999 13:26:31 -0400 (EDT) From: Pat Ford Subject: dis and timming Hi all: does anyone here have details on the way timming is adjusted on a dis ignition. What i know 1) dis module sends out a signal, (refference pulse) and gets a signal back from the ecu 2) the ecu drives another line when it takes over timming control from the dis module 3) the dis module drives a line when a certain rmp is exceeded (500 RPM?) What I'd like to do is make a small controller that I can down load a timming map to. what does the ecu output to the dis to modify the timing. what does the waveform look like.. any help appreciated - -- Pat Ford email: pford@xxx.com QNX Software Systems, Ltd. WWW: http://www.qnx.com (613) 591-0931 (voice) mail: 175 Terrence Matthews (613) 591-3579 (fax) Kanata, Ontario, Canada K2M 1W8 ------------------------------ End of DIY_EFI Digest V4 #359 ***************************** 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".