DIY_EFI Digest Wednesday, 10 September 1997 Volume 02 : Number 313 In this issue: Re: Propane on Fuel Injected Cars Propane Injection Injector Pulse Time Schematic Wanted and O2 Meter comments Re: O2 sensor location Re: Injector Pulse Time Schematic Wanted and O2 Meter comments Re: O2 Sensor Location Re: O2 sensor location Re: O2 sensor location Re: Fuel Pressure.....what to use ? Re: O2 sensor location Map sensor RE: why is rich better for power ?? Re: O2 sensor location Re: Propane on Fuel Injected Cars Re: Fuel Pressure.....what to use ? OBD II - fuel trims (adaptives) Re: Propane on Fuel Injected Cars More females?? [none] See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: clsnyde@xxx.net (Clare Snyder) Date: Tue, 9 Sep 1997 12:50:20 GMT Subject: Re: Propane on Fuel Injected Cars >Greg Wood: > >> I'm kind of curious on this also. Can I use the same >> ECM and just change to propane injectors?? > >Not very likely. If you simply want to use the gasoline computer in >your vehicle you will have a lot of trouble making propane injection >work. Almost universally, propane is utilized in it's vapour phase. As >such, the pulse widths required to inject a stoichiometric amount of >fuel are considerably longer than gasoline. > >Additionally, there aren't any "propane" injectors avaliable, that I >know of. However, natural gas injectors, like those made by Bosch for >Chrysler do work. You will need complete access to the ECM though to >optimize fuel delivery, etc. > >Ideally you would like to inject propane as a liquid into the cylinder, >and gain the effects of charge cooling. However, liquid phase propane >injection is a whole different ball of wax, one that even the propane >industry is reluctant to touch. > >> Are their >> any books written detailing conversions and whats involved? >> I guess thats basically what i'm lookin for. A "How to" book >> that would explain all the pitfalls etc. that are involved in a >> conversion of this type. > >There are books avaliable on converting a vehicle to run on vapour >propane carburation, however information of propane FI is limited at >best (scarce to nil might be a better explination). The propane >industry is presently lagging behind the gasoline industry by a great >many years, and as such there is limited information, parts, and >technical help avaliable for developing propane fuel injection. > >An actual propane conversion is not too difficult. However, if you want >to make it a fuel injection system it will complicate the matter. > >If you've got more questions, fire away. > > >Neall >-- >********************************** >Neall Booth >Bi-Phase Technologies >Development & Applications Engineer >nbooth@xxx.net >********************************** > Contact GFI Control Systems 100 Hollinger Cr Kitchener Ont. Canada (519)576-4270 They are, I believe, responsible for the Chrysler propane injection system, and are number one in that field. ------------------------------ From: J W Hodgson Date: Tue, 9 Sep 1997 09:04:45 -0400 (EDT) Subject: Propane Injection DOE has sponsored a propane vehicle competition in which several university teams converted Chysler products to run on propane. Some teams used gas mixers with O2 sensor feedback, some used gaseous propane injection, and some used liquid propane injection. Simply using gasoline injectors can get you in trouble becasue the lubricity of the propane is not good. For gaseous injection we used Bosch injectors designed for natural gas use. For more detailed info, e-mail me directly and I could send you a technical report or two. Name: J. W. Hodgson Address: Mechanical Engineering Dept e-mail: jhodgson@xxx.edu 414 Dougherty Hall The University of Tennessee voice: (423) 974-5294 Knoxville, TN 37996-2210 fax: (423) 974-5274 ------------------------------ From: David Hoerl Date: Tue, 9 Sep 1997 12:26:01 -0400 (EDT) Subject: Injector Pulse Time Schematic Wanted and O2 Meter comments I recently built the O2 Meter shown in the Projects page. This has been of enormous help in understanding what my BMW Motronics system is up to. However, I find I'd also like to know what is going on in terms of injector pulses under different circumstances. I know there are some commercial LED meters that show low to high injector pulsing. Does anyone have a schematic for such a thing? If its on the 'net somewhere, please let me know by direct email. I highly recommend building that O2 meter! I went to Radio Shack and got a small black box with a circuit card inside for about $2, then bought a cigarette lighter plug which I used to get power. On the signal side (going to the O2 sensor) I put two spade lugs (on male, one female), then ran two wires from inside the car to my O2 sensor location, also with two spade lugs (m&f). (Note - I have the one wire O2 sensor). By attaching the O2 sensor and its ECU wire to the wires going into my passenger compartment, I can now easily connect both spade lugs to the O2 meter and see what the ECU does during closed loop (ie, O2 sensor connected to the ECU and to the meter) and open loop performance (O2 sensor just connected to the meter, the ECU open circuit, in which case the ECU biases the line to stochiometric 0.6 volts, and basically provides standard, unmodified settings. David Hoerl dfh@xxx.com ------------------------------ From: Todd King Date: Tue, 09 Sep 97 09:53:00 PDT Subject: Re: O2 sensor location <<< On a home-built Turbo/EFI performance system using an aftermarket ECU, should the O2 sensor be located before the turbo or after ? If after >>> Do like the oem's do- put it before the turbo. The stock loc on mine is about 2" before the turbo. Todd todd_king@xxx.com ------------------------------ From: Bruce Bowling Date: Tue, 09 Sep 1997 13:32:32 EDT Subject: Re: Injector Pulse Time Schematic Wanted and O2 Meter comments > > I recently built the O2 Meter shown in the Projects page. This has been > of enormous help in understanding what my BMW Motronics system is up to. > > However, I find I'd also like to know what is going on in terms of injector > pulses under different circumstances. I know there are some commercial > LED meters that show low to high injector pulsing. Does anyone have a > schematic for such a thing? > > A few weeks ago, I posted info on how to make an analog gauge version of a pulse width meter from a PIC processor. I also posted the code which ran it. I offered to post the schematic (it is very simple) but then my network connection was lost for a few weeks and so I am not sure if anyone wants the info. The circuit could be adapted to an LED, or better yet maybe an intelligent LCD (Hitachi-controlled). The analog gauge is nice in that it is cheap and will easily show trends. I used a 1 milliamp movement, but any movement will probably work. - - Bruce - -- - ----------------------------------------------------- <<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> - ----------------------------------------------------- Bruce A. Bowling Staff Scientist Thomas Jefferson National Accelerator Facility 12000 Jefferson Ave - Newport News, VA 23606 (804) 249-7240 bowling@xxx.gov/~bowling - ----------------------------------------------------- <<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> - ----------------------------------------------------- ------------------------------ From: Seth Date: Tue, 9 Sep 1997 12:25:52 -0700 (PDT) Subject: Re: O2 Sensor Location On Mon, 8 Sep 1997, Michael Manry wrote: > I would appreciate input on the following qusetion: > > On a home-built Turbo/EFI performance system using an aftermarket ECU, > should the O2 sensor be located before the turbo or after ? If after the > turbo, how far after ? > > Thanks in advance > > Mike M. > Just after the turbo, so when it starts to fall apart, it doesn't take out the turbine wheel. Seth Allen ------------------------------ From: Seth Date: Tue, 9 Sep 1997 12:35:10 -0700 (PDT) Subject: Re: O2 sensor location On Tue, 9 Sep 1997, Todd King wrote: > <<< > On a home-built Turbo/EFI performance system using an aftermarket ECU, > should the O2 sensor be located before the turbo or after ? If after > >>> > > Do like the oem's do- put it before the turbo. The stock loc on mine > is about 2" before the turbo. > > Todd todd_king@xxx.com > Haven't really thought to look at several turbo cars for this feature, but Mitsu eclipses and Audi turbos have them after the turbo, so perhaps there is no universal law for placement... Seth Allen ------------------------------ From: "Christopher G. Moog" Date: Tue, 09 Sep 1997 16:25:31 -0400 Subject: Re: O2 sensor location Todd King wrote: > Do like the oem's do- put it before the turbo. The stock loc on mine > is about 2" before the turbo. > > Todd todd_king@xxx.com Put it after the turbo as my OEM is (Merkur XR4Ti). ------------------------------ From: James Weiler Date: Tue, 9 Sep 1997 13:45:44 -0700 (PDT) Subject: Re: Fuel Pressure.....what to use ? On Tue, 9 Sep 1997, Simon Quested wrote: > ...it's an old system it has 7 pots for the rev range and a pot > to set up the on time at WOT and a master mix pot, so if the 4 > injectors can't supply enough I'll add a 5th injector. cool, I'm jealous. > > Wanting to run 10 - 20 psi on pump gas not proper fuel.... the gas in > the new unleaded is shit if it was in the states it would be banned, > 47% airomatics =-( full of benzine now Should be great for octane rating but must suck for gumming up injectors. Why that formulation I wonder? ......I'd rather have the > lead .....is it true that in America all fuel pumps must have > extractors on the nozzel to suck the fumes away?? Wouldn't know, I'm in Canada. :) good luck guy, sounds like alot of fun jw ------------------------------ From: Michael J Weber Date: Tue, 09 Sep 1997 16:36:49 -0500 Subject: Re: O2 sensor location At 12:35 PM 9/9/97 -0700, you wrote: >On Tue, 9 Sep 1997, Todd King wrote: > >> <<< >> On a home-built Turbo/EFI performance system using an aftermarket ECU, >> should the O2 sensor be located before the turbo or after ? If after >> >>> >> >> Do like the oem's do- put it before the turbo. The stock loc on mine >> is about 2" before the turbo. >> >> Todd todd_king@xxx.com >> >Haven't really thought to look at several turbo cars for this feature, >but Mitsu eclipses and Audi turbos have them after the turbo, so perhaps >there is no universal law for placement... > >Seth Allen > All the Grand Nationals and Turbo Regals have the sensor in the downpipe after the turbo. Mike Weber mweber@xxx.com ------------------------------ From: Simon Quested Date: Wed, 10 Sep 1997 09:55:24 +1200 Subject: Map sensor Hi Everybody out there in list land After having no joy finding a motorola MPX4250 (a place in Auckland will sell me a min. of 20) all I could find was a bosch 0261 230 006 for about US$40 =-( But anyway I now have a map sensor that a friend gave me but I haven't been able to find out anthing about it.... This is the markings OB3 Data System DSM-10 Japan Can anyone give me some info on it? all I need is the pin out. Cheers Simon +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Simon Quested (E-mail questeds@xxx.nz) Computer Technician, Silicon Graphics & Windows NT Support Centre for Computing and Biometrics LINCOLN UNIVERSITY OF NEW ZEALAND Phone (64)(03) 3252811 Ext. 8087 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ http://www.lincoln.ac.nz/ccb/techs/simon/default.htm +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ When the chips are down, the cow is empty. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ------------------------------ From: James Boughton Date: Tue, 9 Sep 1997 19:39:35 -0400 Subject: RE: why is rich better for power ?? Tom, There are a couple of reasons why richer is better if it is power output you are interested in. Let me start with the torque output. According to Heywood (everyone familiar with him?), the indicated mean effective pressure (imep) of an engine is proportional to the fuel conversion efficiency multiplied by the equivalence ratio. Since fuel conversion efficiency falls off with increasing equivalence ratio you end up with a peak between the equivalence ratios of 1.0 to 1.1. If you are unfamiliar with equivalence ratio it is the ratio of fuel/air to stoichiometric fuel/air, thus an equivalence ration of 1.1 is 10% rich. The imep turns out to be proportional to torque output (approx.) and since at any rpm an increase in torque is a subsequent increase in power you end up with more power on the rich side of stoichiometric. Please note that combustion efficiency is not an argument of the above discussion. However, if we think a little about the combustion process we will also find some improvements in power due to statistics. Think about 50 men and 50 women blindfolded in a room together. Now if we tell them to all find a partner of the opposite sex and give them only a minute to do it you will find a few people left without partners (How do you like this game so far?). So lets say, for arguments sake that 4 people were left over. This would be an efficiency of 96%. This is similar to what goes on in the combustion chamber as fuel molecules are wandering around (blindfolded) looking for oxygen molecules. So we ask ourselves, how can we make more couples in the same amount of time? We could add more males and females. This would be the equivalent of turbocharging. But in our case we are going to be stuck with the same number of females (50) regardless:-( So let's try increasing the number of males (more fuel!) Now if we give everyone a minute we are more likely to find that the females are all used up. This is the statistics portion of the power improvement. It also explains why even at stoichiometric air-fuel ratios we have oxygen left over in the exhaust, albeit very little. Here is another cool benefit. By adding more males we also get more females! This would be due to the charge cooling effect of fuel as seen in the case of methanol fueled CART cars. I hope this helps answer your question. Jim Boughton boughton@xxx.net - ---------- From: Tom Cloud[SMTP:cloud@xxx.edu] Sent: Friday, September 05, 1997 10:57 AM To: diy_efi@xxx.edu Subject: why is rich better for power ?? can anyone out there tell me why stoich doesn't make the best power ?? Tom Cloud it IS as bad as you think and they ARE out to get you !! ------------------------------ From: Terry Martin Date: Tue, 09 Sep 1997 17:33:50 -0700 Subject: Re: O2 sensor location Michael J Weber wrote: > > At 12:35 PM 9/9/97 -0700, you wrote: > >On Tue, 9 Sep 1997, Todd King wrote: > > > >> <<< > >> On a home-built Turbo/EFI performance system using an aftermarket ECU, > >> should the O2 sensor be located before the turbo or after ? If after > >> Do like the oem's do- put it before the turbo. The stock loc on mine > >> is about 2" before the turbo. > >> > >> Todd todd_king@xxx.com > >> > >Haven't really thought to look at several turbo cars for this feature, > >but Mitsu eclipses and Audi turbos have them after the turbo, so perhaps > >there is no universal law for placement... > > > >Seth Allen > > > All the Grand Nationals and Turbo Regals have the sensor in the downpipe > after the turbo. > > Mike Weber > mweber@xxx.com It depends on the ECM/PCM/OBC/ECU/VCM-A calibration, (whichever you prefer, computer geeks like alphabet soup), among other things. Pre-turbo results in a different O2 reading than after turbo, simply because the turbo a) adds more time in the exhaust stream, and extracts energy, and, b) because of the delayed sensor reading, post turbo results in a cooled, energy deficient, oxygen used, exhaust stream being measured. If nothing else, O2 measurements are temperature dependant because of the partial pressures of the various gasses. Terry ------------------------------ From: Neall Booth Date: Tue, 09 Sep 1997 20:43:14 -0700 Subject: Re: Propane on Fuel Injected Cars Clare Snyder wrote: > Contact GFI Control Systems > 100 Hollinger Cr > Kitchener Ont. Canada > (519)576-4270 > > They are, I believe, responsible for the Chrysler propane injection system, > and are number one in that field. No, Chrysler developed it's own liquid phase propane fuel injection system. GFI markets a suedo-vapour injection system which is more like throttle body injection than multiport vapour injection. Neall - -- ********************************** Neall Booth Bi-Phase Technologies Development & Applications Engineer nbooth@xxx.net ********************************** ------------------------------ From: Johnny Date: Tue, 09 Sep 1997 19:09:49 -0700 Subject: Re: Fuel Pressure.....what to use ? > On Tue, 9 Sep 1997, Simon Quested wrote: > ......I'd rather have the > > lead .....is it true that in America all fuel pumps must have > > extractors on the nozzel to suck the fumes away?? Ya, the new ones just pour the stuff on the ground instead. - -j- ------------------------------ From: "Joe Chiasson" Date: Tue, 9 Sep 1997 20:58:29 -0500 Subject: OBD II - fuel trims (adaptives) If any one could unravel the mystery behind OBD II short and long term fuel trims (adaptives) it would be greatly appreciated. My interpretation was that short term fuel trims dealt with the short term fuel delivery (i.e. computer increasing or reducing pulsewidth to reach a stoich O2 sensor reading). My interpretation of long term fuel trims is how out of whack the fuel delivery to the engine is, either over an OBD II driving cycle or over the entire driving life of the vehicle, until the ecm is diconnected that is. This is what I thought (now please correct me if I am wrong) untill I ran into this senario with a 1997 Ford F-150 automatic 4.6 L V-8. Under cruising speeds of 55 mph the short term fuel trim was +5% and the long term fuel -7%. Under WOT conditions the short term fuel trim was +33% and the long term -21%. Now under my intial interpretations on how fuel trims were calculated I assumed that at WOT the ecm was increasing the fuel delivery by 33% to reach stoich. But then why would the long term fuel trim decrease? Well this has confused the hell out of me. If anybody can clue me on on what the fuel trims actually mean, and how they are determined (i.e. referenced off the front O2, the rear O2, or no O2 at all) help would be appreciated. J. ------------------------------ From: "Joe Chiasson" Date: Tue, 9 Sep 1997 21:46:51 -0500 Subject: Re: Propane on Fuel Injected Cars > From: Clare Snyder > To: diy_efi@xxx.edu > Subject: Re: Propane on Fuel Injected Cars > Date: Tuesday, September 09, 1997 7:50 AM > > > Contact GFI Control Systems > 100 Hollinger Cr > Kitchener Ont. Canada > (519)576-4270 > > They are, I believe, responsible for the Chrysler propane injection system, > and are number one in that field. > Nope! Chrysler developed their own liquid injection system. GFI's is a vapour system, which technically is not an injected system, atleast on the wavelength we are talking here. The new Ford F-150 dual fuel pick-ups run the GFI system however. As for GFI being number one in that field, maybe its not my place to comment, but I beg to differ. J. ------------------------------ From: A70Duster@xxx.com Date: Wed, 10 Sep 1997 00:52:45 -0400 (EDT) Subject: More females?? In a message dated 97-09-09 19:55:50 EDT, you write: << By adding more males we also get more females! >> I try that my parties, but only get more empty beer cans. :-} See ya, Mike ------------------------------ From: Hannes_Aumueller@xxx.at Date: Wed, 10 Sep 1997 10:03:01 +0200 Subject: [none] Does anyone know where i can find a EPROM File for ECU I want to make a TUNINGCHIP for my FIAT 176 PUNTO 55s MOD VER 1.1 ------------------------------ End of DIY_EFI Digest V2 #313 ***************************** 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".