DIY_EFI Digest Tuesday, 12 August 1997 Volume 02 : Number 270 In this issue: RE: Mono jetronic problems..... Re: Too good to let go by Re: fuel filter location Re: Mono jetronic problems..... Re: TPI Questions Treatise on intake systems Re: TPI Questions Re: TPI Questions Adjusting boost Apology Re: Where are the new concepts going to come from if this is the best there is? Re: Too good to let go by RE:80c535 as contoller Treatise on intake systems Re: Where are the new concepts going to come from if this is the best there is? Eprom switcher Re: TPI Questions Controller Questions Reality of Fuel Consumption Re: TPI Questions Re: TPI Questions RE: Reality of Fuel Consumption Re: magnetron in the column Re: TPI Questions Re: Reality of Fuel Consumption See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: "Jeno Varga (MEPCD)" Date: Tue, 12 Aug 1997 11:00:07 +0100 Subject: RE: Mono jetronic problems..... Hi Waynand, I have a very similar experience with Ford mechanics. I have solved my problem with a fault code reader and a bit of information of my car's ECU. Can you read out your car fault codes? If not I may can help you. It is easy if you have some electronics background. I have a book at home to check your system but I need your engine size and code. I think only a few mechanics up to the job to fix an EFI problem, so I think the best if you try it yourself. Jeno. > ---------- > From: > owner-diy_efi@xxx.en > g.ohio-state.edu] on behalf of Weynand > Kuijpers[SMTP:weynand@xxx.nl] > Sent: 12 August 1997 07:41 > To: diy_efi@xxx.edu > Subject: Mono jetronic problems..... > > Dear people, > > As a newbie on this mailing list I;d like to pop a question to y'all, > because the mechanics in the garage cannot help me with my problem. > This made me so frustrated that I decided to take the problem in my own hands. > > This is what's happening: > > The car I bought is a '90 Audi 80. It has the Bosch mono jetronic EFI > system > installed. The problem is that every time the cooling fluid of the > engine > hits 90 degrees C (is 363 K) I start loosing power, the motor > experiences > hick-ups, and in general does not run very smoothly. > > This short description to the Audi mechanics has resulted in over $500 > in > repair bills, and still the problem is not solved. So I started > looking > in de manuals of fuel injection systems, and read some things about > the > mono jetronic system. If I look at the problem, it seems to me that > the NTC > which measures either engine temperature, or cooling fluid temperature > is broken, and feeding the ECU withj the wrong signal. Or worse, the > ECU > is broken and ... > > Can anyone please share his thoughts with me. The garage has given me > a "card > blanche" and is willing to repair the car at no cost. This time I > want to > instruct them a little....... > > > Thanx in advance, > > Greetings, Weynand > > "Akta Gamat!" > > > Leeloo, "5th element" > > -------------------------oOOO------OOOo---------------------------- > ------ > | Weynand Kuijpers > | > | Unix Support Nederland Unix admin Fokker Space B.V. > | > | Tel. :070-3630462 Tel 071-5245262 > | > | Fax :070-3630470 Email : > unix.admin@xxx.nl| > | Email :weynand@xxx.nl > w.kuijpers@xxx.nl| > | .oooO > | > | ( ) Oooo. > | > ------------------------- \ (-----( > )---------------------------------- > \_) ) / > (_/ > ------------------------------ From: wstrass@xxx.com Date: Tue, 12 Aug 1997 07:16:48 -0400 Subject: Re: Too good to let go by To: DIY --INTERNET DIY From: Wayne Strasser (CED Polymer Development) *** Resending note of 08/12/97 05:21 _______________________________________________________________________ Subject: Re: Too good to let go by ========================================================================= > > Wait a minute. I thought hydrogen was a metal. Hydrogen is a Group 1-A element, together with lithium, sodium, etc. The "light metals" begin with lithium and beryllium, downward through the periodic table. Hydrogen is not classified as a metal because does not form a solid containing mobile electrons. A SOLID PHASE IS NOT REQUIRED TO EXIST TO BE A METAL (MOLTEN IRON IS STILL METAL), BUT I DO AGREE WITH THE CHARGE DELOCATLIZATION (MOBILE ELECTRONS). > Only under the physical parameters that make it a metal. Is glass a > solid? No, it's a supercooled liquid. It has a viscosity (very high, of course). If you measure the thickness of an old window pane, it will be measurably thicker at the bottom. It also changes its internal structure over time. New glass cuts very easily, while old glass tends to shatter. WE CALL IT A SUPERCOOLED LIQUID, BUT IT IS REALLY AN AMORPHOUS SOLID. OLD COMPOSITIONS OF WINDOW GLASS HAD THEIR GLASS TRANSITION TEMPERATURES TOO LOW. A NORMAL HOT DAY WOULD ALLOW MOLECULAR DIFFUSION AND WOULD THEREFORE SAG. I GUESS THE GLASS MANUFACTURES HAVE DONE SOMETHING (SOME KIND OF DOPE OR OTHER IMPURITY) TO ALLOW THE GLASS TO BE SLIGHTLY MORE CRYSTALLINE AND HAVE A HIGHER GLASS TRANSITION AS NOT TO SAG. THE "DOPE" OR OTHER IMPURITY WOULD ALLOW NUCLEATION SITES FOR THE COOLING GLASS DURING MANUFACTURE. THERE SEEMS TO BE ALOT OF INTEREST IN TERRY'S HYDROGEN PROPOSAL. I LOOKED IN SOME RESOURCES, INCLUDING THE WEB, AND FOUND THAT IN THE 80'S LIQUID METALLIC HYDROGEN WASNT EVEN CONSIDERED FEASIBLE...ONLY SOLID METALLIC HYDROGEN. NOW, I GUESS, WITH MORE SPACE EXPLORATION AND LAB EXPERIMENTATION, WE HAVE DISCOVERED THAT HYDROGEN DOES EXHIBIT METALLIC PROPERTIES AT 3000K AND 140GPa. --COOL-- ------------------------------ From: wstrass@xxx.com Date: Tue, 12 Aug 1997 07:21:17 -0400 Subject: Re: fuel filter location To: DIY --INTERNET DIY From: Wayne Strasser (CED Polymer Development) *** Resending note of 08/12/97 00:05 _______________________________________________________________________ Subject: Re: fuel filter location ========================================================================= On Tue, 12 Aug 1997, Simon Quested wrote: > This is what I have found out about installing your own efi..... > > 1) the fuel pump needs to be as clost to the tank as possible. Why? I'm not saying you're wrong. Just asking. Is there something about the way a pump is designed such that it would prefer to push rather than pull? YES, CAVITATION. WHEN THE PUMP IS FORCED TO PULL INSTEAD OF PUSH THE LOCAL PRESSURE FLUCTUATIONS AT THE ROTATING ELEMENT(S) IN THE PUMP DROP BELOW THE BOILING PRESSURE OF THE GASOLINE. AT THIS POINT, THE GASOLINE BEGINS TO VAPORIZE. OBVIOUSLY THIS CAN CAUSE VAPOR LOCK AND DAMAGE TO THE PUMP. THIS PHENOMENON IS EXPONENTIALLY ACCENTUATED WITH INCREASES IN ATMOSPERIC TEMPERATURES. ------------------------------ From: Mikael Andersson Date: Tue, 12 Aug 1997 14:13:24 +0200 Subject: Re: Mono jetronic problems..... Weynand Kuijpers wrote: > Dear people, > > As a newbie on this mailing list I;d like to pop a question to y'all, > because the mechanics in the garage cannot help me with my problem. > This made me so frustrated that I decided to take the problem in my > own hands. > > This is what's happening: > > The car I bought is a '90 Audi 80. It has the Bosch mono jetronic EFI > system > installed. The problem is that every time the cooling fluid of the > engine > hits 90 degrees C (is 363 K) I start loosing power, the motor > experiences > hick-ups, and in general does not run very smoothly. > > This short description to the Audi mechanics has resulted in over $500 > in > repair bills, and still the problem is not solved. So I started > looking > in de manuals of fuel injection systems, and read some things about > the > mono jetronic system. If I look at the problem, it seems to me that > the NTC > which measures either engine temperature, or cooling fluid temperature > > is broken, and feeding the ECU withj the wrong signal. Or worse, the > ECU > is broken and ... > > Can anyone please share his thoughts with me. The garage has given me > a "card > blanche" and is willing to repair the car at no cost. This time I > want to > instruct them a little....... > > Thanx in advance, > > Greetings, Weynand > > > "Akta Gamat!" > > > > Leeloo, "5th element" > > > -------------------------oOOO------OOOo---------------------------------- > > | Weynand > Kuijpers | > | Unix Support Nederland Unix admin Fokker Space > B.V. | > | Tel. :070-3630462 Tel > 071-5245262 | > | Fax :070-3630470 Email : > unix.admin@xxx.nl| > | Email :weynand@xxx.nl > w.kuijpers@xxx.nl| > | > .oooO | > | ( ) > Oooo. | > ------------------------- \ (-----( > )---------------------------------- > \_) ) / > (_/ Try contact cleener in the tps connector, located on the rear side of the throttlebody. This has helped in a lot of cases. Mike. (Audi mech) ------------------------------ From: dzorde@xxx.com (dzorde) Date: Tue, 12 Aug 1997 06:10:15 -0700 (PDT) Subject: Re: TPI Questions I'm lost, for a performance engine, do you want egr or not ? When I built my tpi 350, I pulled the egr valve and stuck a blanking plate over the hole instead, oh, I also put the little metal plates in the manifold gaskets where the egr is meant to breathe through. Was this a mistake (I don't care about economy, only power)? Dan dzorde@xxx.com >> Thanks for the help. >> >> This P/N thing is confusing. I have the JTR book (and a bunch others) >and >> most say not to ground this pin. >> If I remember correctly something to do with idle and deceleration. >Should >> I be concerned???? >> I think a lot of this is tied to an automatic transmission, not manual. >Is >> this true? > >I left mine open..sortta. I'm using Aluminum Corvette heads that do not >have the internal EGR passages in combination with a '86 VIN "F" TPI >manifold. > >The EGR valve is still present and connected, but doesn't actually do >anything since there isn't a supply of exhaust gas to the valve. > >Grounding the EGR feedback wire will set off the SES light (it simulates >the EGR being stuck in the open position) > >Leaving it disconnected will also occasionally set off the SES light (there >are a few cases where the ECM will command the EGR to actuate, then look to >see what happened.) Fortunately, temps down here are high enough that this >doesn't happen often. (been about 4 months since the last time the code >went off) It will also clear itself within a few minutes of driving. > >Someday I'll have an EGR flange welded to one of the exhaust headers to >supply external EGR.. but it's a low priority. > >Curt Martin (cmartin@xxx.com) >Ormond Beach, FL >http://www.america.com/~cmartin >'87 350 TPI Camaro.. (used to be a 2.8L V6 :) > ------------------------------ From: James Boughton Date: Tue, 12 Aug 1997 09:21:02 -0400 Subject: Treatise on intake systems Let me start over since I see the equation included by another writer has affected our conversation. If you consult Heywood's "Internal Combustion Engine Fundamentals" you will find an equation for tuning your intake lengths on page 312. The equation: Tuned rpm = (955)(a)((A)^0.5)/(K)(((l)(Veff))^0.5) where a=speed of sound (Temperature dependent) A=effective cross sectional area of intake l=effective length of intake (basically length from back of valve to end of trumpet) Veff=Effective cylinder volume (typical cylinder volume with piston at 1/2 stroke) K=Fudge factor (typically taken as 2 until some data is in hand) The speed of sound is simply (gRT)^0.5 where g and R are considered constant. If you wanted to be rigorous you could actually vary g and R for temperature, but probably not worth it. T is of course temperature. Now reference 6.27 from Heywood is a paper by R.J. Tabaczysnki titled "Effects of Inlet and Exhaust System Design on Engine Perfromance." In this paper a great deal of work was done to determine appropriate lengths at different average cross sectional areas. The various cross sectional areas were actually shown as different intake velocities (since the velocity and the area are inversely proportional). What Tabaczynski determined (which I don't actually agree with) is that the best intake velocity was between 180 - 200fps (55 - 61m/s). Now to calculate intake velocity the volume displaced during the intake stroke is taken as flowing during the time of the intake stroke. This gives a volume flow rate (length cubed per time). If you divide this quantity by the intake area (length squared) you end up with a (pseudo) velocity (length per time). The volume is the cylinder volume - 500cc in your case. Note that this displacement takes place during half of a revolution. If one revolution takes 1/rpm minutes then 1/(2*rpm) minutes is the length of time for a half of a revolution. Since we are going to divide the volume by the time we end up with V*rpm*2 as the volume flow rate. Then you simply divide by the area and the appropriate conversion factors to get to feet per second or m/s whichever is preferred. I hope this clears up some of the misunderstanding. Please feel free to ask more questions. Jim Boughton ------------------------------ From: Jeffrey R Muehl Date: Tue, 12 Aug 1997 09:03:40 -0500 Subject: Re: TPI Questions I was hoping someone would jump in here. Do you have any evidence of the engine knocking without EGR? I have the same question - do I want it or not? I'm also not concern with economy, only power. >I'm lost, for a performance engine, do you want egr or not ? When I built my tpi 350, I pulled the egr valve and stuck >a blanking plate over the hole instead, oh, I also put the little metal plates in the manifold gaskets where the egr is >meant to breathe through. Was this a mistake (I don't care about economy, only power)?>> > > >Dan dzorde@xxx.com > > >The EGR valve is still present and connected, but doesn't actually do >anything since there isn't a supply of exhaust gas to the valve. > >Grounding the EGR feedback wire will set off the SES light (it simulates >the EGR being stuck in the open position) > >Leaving it disconnected will also occasionally set off the SES light (there >are a few cases where the ECM will command the EGR to actuate, then look to >see what happened.) Fortunately, temps down here are high enough that this >doesn't happen often. (been about 4 months since the last time the code >went off) It will also clear itself within a few minutes of driving. > >Someday I'll have an EGR flange welded to one of the exhaust headers to >supply external EGR.. but it's a low priority. ------------------------------ From: "Gregory Chan" Date: Tue, 12 Aug 1997 10:49:03 EDT Subject: Re: TPI Questions I was under the impression that EGR was to clean up emissions by recirculating exhaust gas. I read that a performance mod was to disable the EGR valve with big cams. gchan@xxx.ca > > > I was hoping someone would jump in here. > > Do you have any evidence of the engine knocking without EGR? > > I have the same question - do I want it or not? I'm also not concern with > economy, only power. > > > > > > >I'm lost, for a performance engine, do you want egr or not ? When I built > my tpi 350, I pulled the egr valve and stuck >a blanking plate over the > hole instead, oh, I also put the little metal plates in the manifold > gaskets where the egr is >meant to breathe through. Was this a mistake (I > don't care about economy, only power)?>> > > > > > >Dan dzorde@xxx.com > > > > > >The EGR valve is still present and connected, but doesn't actually do > >anything since there isn't a supply of exhaust gas to the valve. > > > >Grounding the EGR feedback wire will set off the SES light (it simulates > >the EGR being stuck in the open position) > > > >Leaving it disconnected will also occasionally set off the SES light > (there >are a few cases where the ECM will command the EGR to actuate, then > look to >see what happened.) Fortunately, temps down here are high enough > that this >doesn't happen often. (been about 4 months since the last time > the code >went off) It will also clear itself within a few minutes of > driving. > > > >Someday I'll have an EGR flange welded to one of the exhaust headers to > >supply external EGR.. but it's a low priority. > > > > ------------------------------ From: bibie@xxx.com (Bibiana Lim) Date: Tue, 12 Aug 1997 22:49:54 +0800 Subject: Adjusting boost Thanks Max, You Wrote: >I was going through some of the other posts on this thread and then I >realized I wasn't sure what year your car is. If it's late model, like >89-95, then its got an SR20DET engine which is a really good engine. Mine is a CA18DET (ECCS with direct injection). >engine that has less support for it in the aftermarket. Anyway, the company >I mentioned can supply products for both engines. Ok..I'll checkout Mr.Clark on the possibilities. Appreciate the tip!! Later Bibie ------------------------------ From: wstrass@xxx.com Date: Tue, 12 Aug 1997 10:54:30 -0400 Subject: Apology To: DIY --INTERNET DIY From: Wayne Strasser (CED Polymer Development) _______________________________________________________________________ Subject: Apology Is everyone getting my mail twice?? I dont know why my mailing system would be doing this. I am sorry if this is happening. I hate to litter mail boxes. Everyone's input will be appreciated. _______________________________________________________________________ Wayne Strasser wstrass@xxx.com ------------------------------ From: Terry Martin Date: Tue, 12 Aug 1997 08:02:26 -0700 Subject: Re: Where are the new concepts going to come from if this is the best there is? Michael McBroom wrote: > > Terry Martin wrote: > > > > Fuel injection is one of those concepts that make you go DOUGH! However,... > Thank you for that, Terry. Now go away. And start practicing what you > preach from now on. Pedal your blinkety-blink bicycle to work. > > -- > Best, > > Michael McBroom Hmmm. Methinks you didn't. I also posted this. Yeah, I would be impressed if the carburetor by itself could do 100mpg. According to my weed eater, you can carry it and it gets about 4mpg. Add 1 gallon weight of the fuel load and the fuel by itself couldn't get 100 miles, much less dragging a fuel tank, carburetor, engine, chassis, and on and on, more and more massive, until you get the guy that proposed it as fact, who is full of shit and couldn't make 100 miles on his own feet dragging all that crap behind him. Is that independent enough? More practically, at what speed? Even a human can go 100 miles on way less than a gallon of fuel, as long as he doesn't cover himself in the entrapments of heat engines. With a gallon of gas, he probably wouldn't make it back to the car without a Coke. Terry ------------------------------ From: Terry Martin Date: Tue, 12 Aug 1997 08:05:58 -0700 Subject: Re: Too good to let go by Ken Mayer wrote: > > > > Wait a minute. I thought hydrogen was a metal. > > Hydrogen is a Group 1-A element, together with lithium, sodium, etc. The > "light metals" begin with lithium and beryllium, downward through the > periodic table. Hydrogen is not classified as a metal because does not > form a solid containing mobile electrons. > > > Only under the physical parameters that make it a metal. Is glass a > > solid? > > No, it's a supercooled liquid. It has a viscosity (very high, of course). > If you measure the thickness of an old window pane, it will be measurably > thicker at the bottom. It also changes its internal structure over time. > New glass cuts very easily, while old glass tends to shatter. > > Ken > :-) Exactly, appearances tend to be deceiving. Terry ------------------------------ From: dusher@xxx.com Date: Tue, 12 Aug 1997 15:46:14 BST Subject: RE:80c535 as contoller thanks to everyone who has replyed so far!. Maybe thinking of an idea like 'jwebb's reply of a small single cyclinder engine ie 'lawn mower' type!. or maybe a old series 3 Land Rover! 2286 cc engine mmmmm. Im a newbie to this group, So far seems great! loadsa ideas etc ok .oh yea one other thing have made an Elector 80c535 board i guess the one about 3 yrs ago?,just messing with switches and LED's on the ports and pots on the analogs!! oh well its the only way to learn! ........bye Dave G6ZKC.... - -- ------------------------------ From: wstrass@xxx.com Date: Tue, 12 Aug 1997 11:48:41 -0400 Subject: Treatise on intake systems To: DIY --INTERNET DIY From: Wayne Strasser (CED Polymer Development) *** Resending note of 08/12/97 11:24 _______________________________________________________________________ Subject: Treatise on intake systems ========================================================================= (The speed of sound is simply (gRT)^0.5 where g and R are considered constant. If you wanted to be rigorous you could actually vary g and R for temperature, but probably not worth it.) Jim: I have a question....how can g (is this gravitational constant?) and R (the universal gas constant) vary with temperature? ------------------------------ From: Tom Cloud Date: Tue, 12 Aug 1997 11:25:22 -0500 Subject: Re: Where are the new concepts going to come from if this is the best there is? >> Terry Martin wrote: >> > >> > Fuel injection is one of those concepts that make you go DOUGH! However,... >Michael McBroom wrote: >> >> Thank you for that, Terry. Now go away. And start practicing what you >> preach from now on. Pedal your blinkety-blink bicycle to work. and Terry retorted: >Hmmm. Methinks you didn't. I also posted this. > >Yeah, I would be impressed if the carburetor by itself could do 100mpg. >According to my weed eater, you can carry it and it gets about 4mpg. [ snip ] >doesn't cover himself in the entrapments of heat engines. With a gallon >of gas, he probably wouldn't make it back to the car without a Coke. > >Terry Terry, you appear to be a very smart man .... perhaps you don't belong here ;-) .... one very redeeming item though, you did mention Coke and not Pepsi 8^) I would like to interject a couple of things 1 - I'm not a very smart man (thought I'd clear that up right away 8^) 2 - I have a major in Philosophy and Greek ... don't remember nothin' 'bout nobody's razor 3 - following your logic, walking must be the least efficient form of energy, since it was "accidental" (well, I guess crawling is mebbe even less efficient) 4 - I sincerely respect your thoughts on the energy thing but, when will we get that the global warming crisis is a bunch of crap (a 1 degree rise during the short time we've measured temps is nothing to a planet that has experienced some pretty serious warming/cooling trends long before anyone ever heard of R12 -- in fact long before there WAS anyone !! ). I look forward to the development of something not nearly so crude as a reciprocating engine or the burning of petroleum products to power it, and I concur that it will happen some time, but .... I remember when I was in elementary and junior high looking at the Popular Science mags (this was back in the 50's) .... there was lotsa articles on anti-gravity devices and nuclear power and much discussion about how we were going to have problems controlling the airways since EVERYBODY was going to have a personal flying saucer (or something like that) -- sorta a George Jetson kinda world. And this was pre- dicted to happen in less than 20 years .... it's been over 40 years and I haven't seen any movement. My 1949 Ford and my '52 Studebaker Champion are not far removed from the technology of today, as also the aeroplanes (well, there has been some major movement in turboprops and jets) I guess what I'm saying is that (a) I (honestly) recognize the intelligence of our list members -- and of yourself but (b) I don't see us moving away from the reciprocating engine and fossil fuels in the near future (no, not even during the lifetimes of our children) unless forced to do so by an international nanny (read UN) run by people who know oh-so-much-better than the rest of us low-life slugs. Tom Cloud ------------------------------ From: "Peter Rueb" Date: Tue, 12 Aug 1997 18:52:53 +0200 Subject: Eprom switcher Hi, I promised to make some suggestions to improve the eprom switcher. Here they are. The main problem is to make shure that the adress data does not become instabil while there is an access to the eprom. The result may be only a hickup or even worse. My idea now is to allow changings to the two relevant adress lines only when there is no access. The parts are a 7474 (double flipflop) and a bunch of or-gatters. Connect each two normal adress line to a or-gatter and connect all gatter outputs together to the Clock line of the 7474. On the input sides of the 7474 are the two switches with their 4.7k pulldown resistors. The outputs of the 7474 go to the relevant adress lines of the eprom. The preset and reset lines are always high. My thought is, that when the adress status changes from low to high there will soon be an access. At that moment the status of the switches is added to the other lines and does what it shall do. I also thought of connecting Clock with inverter direct to the active low OE of the eprom, because the 7474 has a very short delay of around 15ns, but maybe that is a bit to late. (Maybe someone wants to test it with a fast osci; i have none) It is still important to use bounceless switches (scsi id-selector) and program codes that are only different in the table section. If you use totally different eprom contents even that wont work. Just some thoughts, every improvement welcome. Maybe there is another way to get rid of the or-gatters. Peter Rueb s68558@xxx.de ------------------------------ From: clsnyde@xxx.net (Clare Snyder) Date: Tue, 12 Aug 1997 17:26:00 GMT Subject: Re: TPI Questions > >I was under the impression that EGR was to clean up emissions by >recirculating exhaust gas. I read that a performance mod was to >disable the EGR valve with big cams. > >gchan@xxx.ca >> Big cams blead off effective compression at low speeds, where the ping is usually the problem. A big cam can negate the requirement for EGR . Ping at full throttle is not affected by EGR as it is shut down in that mode My opinion, only, for what it is worth >> >> I was hoping someone would jump in here. >> >> Do you have any evidence of the engine knocking without EGR? >> >> I have the same question - do I want it or not? I'm also not concern with >> economy, only power. >> >> >> >> >> >> >I'm lost, for a performance engine, do you want egr or not ? When I built >> my tpi 350, I pulled the egr valve and stuck >a blanking plate over the >> hole instead, oh, I also put the little metal plates in the manifold >> gaskets where the egr is >meant to breathe through. Was this a mistake (I >> don't care about economy, only power)?>> >> > >> > >> >Dan dzorde@xxx.com >> > >> > >> >The EGR valve is still present and connected, but doesn't actually do >> >anything since there isn't a supply of exhaust gas to the valve. >> > >> >Grounding the EGR feedback wire will set off the SES light (it simulates >> >the EGR being stuck in the open position) >> > >> >Leaving it disconnected will also occasionally set off the SES light >> (there >are a few cases where the ECM will command the EGR to actuate, then >> look to >see what happened.) Fortunately, temps down here are high enough >> that this >doesn't happen often. (been about 4 months since the last time >> the code >went off) It will also clear itself within a few minutes of >> driving. >> > >> >Someday I'll have an EGR flange welded to one of the exhaust headers to >> >supply external EGR.. but it's a low priority. >> >> >> >> > > ------------------------------ From: Jason Walters Date: Tue, 12 Aug 1997 12:22:22 -0700 Subject: Controller Questions Questions for this list: I'm sorta new to electronics. I'm in it partially out of interest, and partly out of necessity. (I have a gizmo that I want to build, but it is UNWIELDY, and I need a computer to keep it in check.) Because the project I'm working on borrows heavily from the technologies discussed in this group, I learn a lot by hanging out. My only problem is that I''m not exactly a microcontroller whiz. I tried to ease into the area with Basic Stamps, and I found this was a good introduction. But I'm quickly finding out that my hardware is lacking. The controller does not have enough speed or space to house all of the code, among other limitations (stamps hate math). So I guess my questions are: 1. If you had to pick a controller to learn on, which one would it be? Say, to convert a weed-eater to EFI. Are we talking big bucks? Do you program these controllers in C or Assembly? Is it a quantum leap from the personal computer C world to the device level? (I'm a VB programer that knows just enough C to be dangerous. I'm often tempted to just grab a data-acquisition board and run this project with my PC . . . so I don't have to take this microcontroller plunge. But something tells me I'll find this PC solution also lacking in the end.) 2. (After I have learned a bit more) If you had to pick a controller to monitor temperature and pressure, and vary an ignition and a fuel injection firing pattern at the same time, which controller would you use? Do you use multiple controllers for all these tasks, or is your code multi-threaded? Or, are these microcontrollers so fast that the interference with the firing sequences is negligible? 3. Are there any other mailing-lists you monitor besides this list that deal specifically with microcontroller topics? Are there any mailing lists that deal with metal working / machining / CNC stuff? Jason Walters jasonw@xxx.com ------------------------------ From: Frederic Breitwieser Date: Tue, 12 Aug 1997 02:16:26 -0400 Subject: Reality of Fuel Consumption >> Thank you for that, Terry. Now go away. And start practicing what you >> preach from now on. Pedal your blinkety-blink bicycle to work. Up until now, I was going to stay out of the slander . While that particular website and owner of said site (100MPG Carbeurators) might be full of horse-bunk, just keep in mind several things. 1. Until Columbus, the world was flat, not round. 2. In 1890's, the first gasoline engine rotated (where did that leave the horses?) 3. In the early 1900's Kitty Hawk flew. After 100 years of really bad designs. 4. Certain purpose-built automobiles have broken the 300MPH bracket. 5. Stealth fighers exist. (we think). 6. Helicopters can fly straight up, with the rotor assembly held on by a single grade 5 aircraft nut. (okay, a big one) 7. Submarines exist. 8. We've been to the moon. Several times. 9. We have color Kodak's of Venus, Jupiter, and continue to send trash into space. 10. Atomic energy actually works. Atoms also aren't the smallest thing we've seen (quarks ). I could bore everyone with a long list of things that 20 years before each thing occured in history, the vast majority of the population at that time said "bullshit". And while we don't have 100MPG cars, the technology is right around the corner. Advanced materials are constantly being developed, new ideas form, people think. The Wankel engine was a fantastic example of a new idea. No pistons. Piston engines have been around since 1903. Its 1997. Its time for a new idea folks. Cheers :) Frederic Breitwieser Homebrew Automotive Mailing List Bridgeport, CT 06606 http://www.geocities.com/MotorCity/Downs/4605/index.html 1989 AG Hummer 4-Door 1993 Supercharged Lincoln Continental 2000 Mid-Engine Sports Car - --- ------------------------------ From: bwmsbldr@xxx.com (William A Williams) Date: Tue, 12 Aug 1997 13:24:32 -0600 Subject: Re: TPI Questions The function of EGR is to dilute the mixture with an inert component with the intention of keeping the peak combustion temperature below 3400 degrees F by displacing some of the O2. Above this temperature the formation of nitrous oxides is greatly accelerated. Any inert gas will do. You could bleed in Argon or CO2 or N2 and accomplish the same objective. Or you could inject H2O as a liquid and get both the displacement as well as the cooling effect of evaporating the liquid to a vapor. As far as power is concerned it is very doubtful that EGR will provide more power. The effects that it has can be better achieved in other ways. Bill in Boulder ---- "Engineering as an Art Form" ---- ------------------------------ From: "Gary Derian" Date: Tue, 12 Aug 1997 15:54:19 -0400 Subject: Re: TPI Questions When nitrogen and oxygen (air) are combined at high temperatures nitrigen oxides are formed. Nitrogen oxides are an ingredient which leads to the formation of ground level ozone. EGR adds exhaust, an inert gas, to the intake. This dilutes the air/fuel mixture and lowers the combustion temperature which reduces the formation of NOx. Lower combustion temperature also makes an engine less prone to detonation. The less NOx created in the engine, the less is emitted out the exhaust, even with 3-way catalysts. Most but not all engines have EGR. In the bad old days of the 70's, engines ran with EGR and retarded spark. This led to a great loss of economy. Modern engine controls can advance the spark during heavy EGR use. The EGR permits lots of advance without detonation. This gets back most all of the economy. When EGR is removed, the part throttle advance must be cut back to "normal" levels otherwise detonation will occur. At full throttle, EGR is not used so spark advance and power are already at proper levels. Gary Derian - -----Original Message----- From: Clare Snyder To: diy_efi@xxx.edu> Date: Tuesday, August 12, 1997 2:58 PM Subject: Re: TPI Questions >> >>I was under the impression that EGR was to clean up emissions by >>recirculating exhaust gas. I read that a performance mod was to >>disable the EGR valve with big cams. >> >>gchan@xxx.ca >>> > >Big cams blead off effective compression at low speeds, where the ping is >usually the problem. A big cam can negate the requirement for EGR . Ping at >full throttle is not affected by EGR as it is shut down in that mode > >My opinion, only, for what it is worth > ------------------------------ From: "David Randall (SMS) (Volt Computer)" Date: Tue, 12 Aug 1997 13:38:40 -0700 Subject: RE: Reality of Fuel Consumption < people think. The Wankel engine was a fantastic example of a new > idea. No > pistons. Piston engines have been around since 1903. Its 1997. >> > --- I saw the patent for the original rotary engine this weekend... (ie wankel like engine) it was dated 1908!! Pretty cool. I'm a rotorhead (drive/love/live/eat/breath Rx7's) and know from following them for the last 16 years, they are awesome engines, even if they haven't made the mainstream. Since we're on this list for the purpose of expanding our knowledge of FI systems, it just seems fitting to keep an open mind! Dave R ------------------------------ From: Todd King Date: Tue, 12 Aug 97 13:48:00 PDT Subject: Re: magnetron in the column <<< > > I know a heavy duty mechanic in charge of the mechanical shop at a > > mill that thinks installing a magnetron out of a conventional oven > > into the manifold will "energize" the gas charge and produce smaller > > droplets resulting in greatly improved efficiency. > He'd be better off mounting that Magnetron in the steering column. What a great anti-theft device.......... >>> You guys are too much! <*har-har*> Just about lost my Coke I was sipping on at the time... Now you know a castration statement like that is risky in the current political/social/criminal rights climate! Todd tking@xxx.com Deep thought for the day: Why doesn't Tarzan have a beard? ------------------------------ From: "Gary Derian" Date: Tue, 12 Aug 1997 17:15:11 -0400 Subject: Re: TPI Questions - -----Original Message----- From: Gary Derian To: diy_efi@xxx.edu> Date: Tuesday, August 12, 1997 3:54 PM Subject: Re: TPI Questions >When nitrogen and oxygen (air) are combined at high temperatures nitrigen >oxides are formed. Nitrogen oxides are an ingredient which leads to the >formation of ground level ozone. EGR adds exhaust, an inert gas, to the >intake. This dilutes the air/fuel mixture and lowers the combustion >temperature which reduces the formation of NOx. Lower combustion >temperature also makes an engine less prone to detonation. The less NOx >created in the engine, the less is emitted out the exhaust, even with 3-way >catalysts. Most but not all engines have EGR. > >In the bad old days of the 70's, engines ran with EGR and retarded spark. >This led to a great loss of economy. Modern engine controls can advance the >spark during heavy EGR use. The EGR permits lots of advance without >detonation. This gets back most all of the economy. When EGR is removed, >the part throttle advance must be cut back to "normal" levels otherwise >detonation will occur. > >At full throttle, EGR is not used so spark advance and power are already at >proper levels. > >Gary Derian > >-----Original Message----- >From: Clare Snyder >To: diy_efi@xxx.edu> >Date: Tuesday, August 12, 1997 2:58 PM >Subject: Re: TPI Questions > > > >>> >>>I was under the impression that EGR was to clean up emissions by >>>recirculating exhaust gas. I read that a performance mod was to >>>disable the EGR valve with big cams. >>> >>>gchan@xxx.ca >>>> >> >>Big cams blead off effective compression at low speeds, where the ping is >>usually the problem. A big cam can negate the requirement for EGR . Ping at >>full throttle is not affected by EGR as it is shut down in that mode >> >>My opinion, only, for what it is worth >> > > ------------------------------ From: Terry Martin Date: Tue, 12 Aug 1997 14:32:28 -0700 Subject: Re: Reality of Fuel Consumption Frederic Breitwieser wrote: > > >> Thank you for that, Terry. Now go away. And start practicing what you > >> preach from now on. Pedal your blinkety-blink bicycle to work. Insert retraction > > Up until now, I was going to stay out of the slander . > > While that particular website and owner of said site (100MPG Carbeurators) > might be full of horse-bunk, just keep in mind several things... Exactly my point, for anybody that didn't just dump on me without reading what I actually wrote. Fuel injection is the most probable means to breach the hurdle of hydro-carbon fueled piston engine machines. Carburetors have out lived their usefulness, and EFI provides the technology necessary to bring in a replacement without disrupting the capitalist structure within which all of this has to work. I, by the way, am an unabashed self-employed capitalist. ------------------------------ End of DIY_EFI Digest V2 #270 ***************************** 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".