DIY_EFI Digest Thursday, 4 January 1996 Volume 01 : Number 001 In this issue: RE: More EFI vendor info >> SDS EM-1 Motronic on a BMW motorcycle More SDS info Re: General question Time for saturation??? Re: Gasification Re: Motronic on a BMW motorcycle More EFI vendor info Re: Gasification See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Derrick Early Date: Wed, 3 Jan 96 6:40:25 "EST Subject: RE: More EFI vendor info >> SDS EM-1 Hi Bradley, I'm interested in hearing more. What sensor inputs does the unit handle? How many map points for ignition and fuel are allowed? Can you program the rpm scale? Yours, - -- Derrick Early early@xxx.mil ------------------------------ From: igreaves@xxx.uk (Ian Greaves) Date: Wed, 3 Jan 96 19:06 GMT Subject: Motronic on a BMW motorcycle In-Reply-To: <199601011110.GAA11257@xxx.edu> Hi guys! I've recently purchased a '93 BMW K1100RS motorcycle. The thing runs O.K. when warm but the warming up phase is bloody 'orrible! It always fires (starts) when cold, but then will often only run on three until it's cleared it's throat. I have to keep the throttle slightly open otherwise it dies instantly. All this is accompanied by clouds of hazy unburned fuel and that rich smell, coming from the exhaust. Basically, the machine is running well rich. (About 20mpg when running warmed up!!, that's at least double the consumption I'd expect.) I've replaced the air filter and spark plugs. Upon dismantling bits of the bike, I discover that the engine management uses a MAP sensor (I thought it was hot wire!) with vacuum tubes everywhere!! The water jacket thermistor, and the intake air thermistor measure about 4 K Ohms at ambient temp. (say 10 degrees C, not unreasonable?) I can't find any obvious vacuum leaks in the piping, and I've opened/remade all the plug in connectors around the place. Any Ideas, anyone, before I admit defeat and go back to the dealer and his analyser!! In fact, does anyone know anything about this particular Motronic system. How does one read any fault codes? I see a three terminal connecter, I suppose this would be a serial port. Is it clocked, or does data just fall out of it asynchronously? What's the baud rate, levels etc. Also any basic set up data? (Throttle pot voltage at idle, etc.) If anyone knows anything, let me know. a) I'd love to learn all about this version of Motronic, as it's not covered in any of my books. (only K,L and LH in the book!) and b) I might just fix my bike!! yours Ian Greaves, in London U.K. ------------------------------ From: marchil@xxx.net Date: Wed, 03 Jan 96 15:08:18 Subject: More SDS info I have an SDS EM-1 It is set up to be used on a 2 rotor wankel engin in staged injection mode thus i have 2 Primary 2 secondary injectors, the injector driver is of the peak and hold type. The setup is easy you have a small hand held 2X20 lcd with 7 push butons all u have to do is cycle through the diferent values ....etc It works fine, easy to tune, A neat mixture trim helps you get a rough mixture closer to what you are looking for it varies your seting by +- 20%. I have not had any problems All sensors and wires are included but the injectors are left up to you and the manifold pressure sensor are optional. I opend up the box and found not much filtering, shielding,the cpu is a Motorola 68HC11 8bit micro,the code is set up as 8k eeprom data for the look up table and 8k code of programing. If looking fore a racing box i would not recomend this one unles u have R type ign wires, and the box is in the car. I could be emailed for more info. Thanks! //---------------------------------------------------------------------------- // Marchil@xxx.NET // Alain Marchildon // 1271 Bernard West // Outremont, Quebec Canada // H2V 1V8 ------------------------------ From: adh@xxx.us Date: Wed, 3 Jan 96 19:20 EST Subject: Re: General question From: pantera@xxx.com (David Doddek) Subject: Re: General question Firing on the open valve is a controversial subject. Some research says that firing on the open valve does not give a good burn since the droplets from the injector are too large. It is believed that injecting on the closed valve will allow some of the heat of the valve to be used to evaporating the fuel, ( liquid gas does not burn, only the vapor. thus the catoletic converter.) It is also believed that the high velocety air present when opening the valve will create better atomization then the injector. in line with this, i've been thinking about preheating the gas in the fuel rails so that it would vaporize better upon injection. this would work best with avgas, which has a narrow [and high] vapor range. temperature control is one obvious requirement. gasoline consistency is another. on balance, i don't really think it will work, because you would constantly be on the bleeding edge of vapor lock... _______________________________________________________________________________ Andrew Hay LIFE, n: A phenomenon that resists the second law of thermodynamics adh@xxx.us ---Schroedinger ------------------------------ From: MTaylorfi@xxx.com Date: Wed, 3 Jan 1996 21:26:15 -0500 Subject: Time for saturation??? Hey all there, Wondering if I could find out the length of time it takes an ignition coil to energize (roughly). Also, does one need to let the coil reach peak saturation or is, lets say, "half charged" enough to get a good spark. Would appreciate the help. Thanks See ya, Mike ------------------------------ From: pjwales@xxx.net (Peter Wales) Date: Wed, 03 Jan 1996 23:46:43 -0500 Subject: Re: Gasification These threads which have discussed injecting on the back of valves and preheating the mixture remind me of a project I started many years ago, and never finished. Maybe I could resurrect it? The premise was that the most efficient combustion would be of a gas. This would mean transferring the vapour into a gaseous state, which I believe has infinitely small droplet size. Heating the liquid to give it energy would approach this, but is impractical for obvious inlet temperature reasons. The solution I decided to approach was that of ultrasonic vibrations, and I looked for an ultrasonic device which would atomise the vapour into a gas. The reason for this is that the smaller the droplet size, the faster it burns and thus the more complete combustion, by the time the gas reaches the exhaust. Vibrating the liquid ultrasonically should break it up into micro droplets. I found a transducer, but it was $7000 and this was out of reach of my casual research budget. I later heard of Plessey in England making some prototypes of an ultrasonic injector, but the manufacturers of the vehicles were not interested and so the project was dropped and by the time I got to it, all of the injectors had disappeared. I have since heard of many other attempts to produce gaseous mixtures, none of which have come to market. Does anyone know of anything which is now available which could prompt further research into this project? Peter Wales President Superchips Inc Chairman Superchips Ltd "Timing is everything" ------------------------------ From: Land Shark Date: Wed, 03 Jan 1996 22:21:05 -0700 Subject: Re: Motronic on a BMW motorcycle At 19:06 1/3/96 GMT, you wrote: >I've recently purchased a '93 BMW K1100RS motorcycle. >The thing runs O.K. when warm but the warming up phase is bloody >'orrible! Ian, check out the BMW Motorcycle WWW pages, which should be reachable thru an index like Yahoo ... one of the guys there did a whole bunch w/ MC Motronic ... Jim ------------------------------ From: dave.williams@xxx.us (Dave Williams) Date: Wed, 03 Jan 1996 17:18:00 +0000 Subject: More EFI vendor info - -> Simple Digital Systems is now offering its new, low-cost EM-1D and E - -> management systems for use on 4, 6, and 8 cylinder engines. The I've written them twice and never got a response. They don't seem particularly enthusiastic about selling anything. ------------------------------ From: ken@xxx.no (Ken-Arne Jensen) Date: Thu, 4 Jan 1996 08:57:04 +0100 (MET) Subject: Re: Gasification > These threads which have discussed injecting on the back of valves and > preheating the mixture remind me of a project I started many years ago, and > never finished. Maybe I could resurrect it? > > The premise was that the most efficient combustion would be of a gas. This > would mean transferring the vapour into a gaseous state, which I believe has > infinitely small droplet size. Heating the liquid to give it energy would > approach this, but is impractical for obvious inlet temperature reasons. > I talked to an marine tech guy some time ago, and he said that in fact a carburetor does a fairly good job of vapourizing the gaz. Of course EFI is better totally, but the vapourizing is good for a carb. He also mentioned one problem with EFI and the use of the back of the valves to vaporize, is that this might crack the valves under extreme conditions. Anyone who wants to comment on this? //// Ken-Arne Jensen // E-Mail: ken@xxx.no / /// Computer Science Department // URL: http://www.cs.uit.no/~ken // // University of Tromsų // Phone: +47-776-44042 /// / N-9000 Tromsų, NORWAY // Fax: 44054 (barcode="ken@xxx.ui") //// ------------------------------ End of DIY_EFI Digest V1 #1 *************************** 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".