DIY_EFI Digest Thursday, August 26 1999 Volume 04 : Number 489 In this issue: Re: Wide range O2 sensor Re: Idiot qestions for lazy newby Ignition Coils. Integrating Saab (bosch LH) and VW knock sensing ignition VW intake See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- Date: Wed, 25 Aug 1999 12:06:50 -0700 (PDT) From: Orin Eman Subject: Re: Wide range O2 sensor > Personally, I'd start with EGOR, but that's just me. :) Speaking of EGOR, is he ready yet? Orin. ------------------------------ Date: Wed, 25 Aug 1999 15:15:16 -0700 (PDT) From: "Jon V." Subject: Re: Idiot qestions for lazy newby Bill Shaw Wrote: > I don't think you said what type of car it is, Groan... I figured that would rear its ugly head! You are quite right, I didn't say... because I didn't want to be laughed out before I was ever in, and even I have a certain amount of pride. No, I don't think I'm going to let you people do that to me. The car is my business, thank you very much. The engine... oh, screw it. You people will laugh at me anyway, so I might as well... The engine is a Lotus 907E. Basically it is your textbook modern econobanger, except it came from England, so it doesn't work most of the time. Canted, DOCH, 16V, 2L, redline somewhere around peak HP... a nice little engine if you don't mind the little things like needing to break your wrists to reach the distributor. Looking through the list archives I notice at least one other person was interested in EFI for it, but I think he was buying an aftermarket system. It has a pair of nifty thingimawhatsit carbs... a rather snazzy design if you are into such things, sort of a MAP sensor and throttle body with mechanical feedback system to balance the air flow against fuel flow. You don't actually control the throttle, you richen the mixture, and it regulates based on MAP... at least that's how I understand the damn things. They were designed for emissions. Anyway, they are British, and I don't need to tell any of you what that means. > ... but I think I'd start by finding it's > mid 80s to early 90s closest equivalent in a junkyard and scavenge the intake, > throttle body, sensors, wiring harness, computer, air cleaner, plumbing, and anything > else that may look interesting. The only EFI versions I know of are either aftermarket (TEC-II) or I-don't-want-to-think-about-it expensive, and they aren't likely to turn up in a junk yard either way, which leaves me fitting some other engine's EFI. That is not such a bad idea, either. I bet the EFI system from a modern GM fourhole would work fairly well... but I am way too ignorant to know what to look for right now or what my own limits are. > That can usually give you a real good head start. I need any sort of start I can get... and head starts are the best... that way I have a chance to maybe finish inside the pack. Hey! I did say *maybe*... > I > was lucky enough to connect with a guy who was parting out a FI Spider. You can see it > at http://www.connix.com/~bshaw/fiatefi.html. Sweet car... very true-blue... and it even has a stereo! Mine doesn't have that... now I'm jealous. Sigh. I bet my car won't look 1/2 as good as yours when I am done... but bugged out coworkers (who are getting very nervous right now) as my witness, I *will* have a car that looks 1/2 as good. It will even have sun visors and (gasp) a top... someday. Right now I am content to have the wind in my hair, the sun on my face, and purr of a leaky exhaust system to keep me company as I wind my lonesome way home. And, of course, an extra engine waiting there, beckoning me to my doom. > If you want to get real fancy, you might also take a look in the efi-232 list, it > looks like they're starting a group buy on the new EFI-232 board. I'm planning on checking it out, but I'm still too ignorant to know what I'm looking at... or how much it will cost. Cost is still important to me. Thanks, - -Jon Sex without class consciousness cannot give satisfaction, even if it is repeated until infinity. -- Aldo Brandirali (Secretary of the Italian Marxist-Leninist Party), in a manual of the party's official sex guidelines, 1973. ------------------------------ Date: Wed, 25 Aug 1999 15:21:47 -0700 From: "John Dammeyer" Subject: Ignition Coils. Hi, I ran into the same problem when we started using the FORD Quad Coil except I figured out that at 12V the amount of current was unreasonable so I didn't bother destroying the coil. You have several alternatives: More than likely the coil is used with some sort of Capacitive Discharge circuit or else a current limiter. Current limiting is useful because the low resistance and high inductance allows a very short dwell time; the time the current is building up and flowing in the coil. Then when the current flow is stopped (points open), the magnetic field collapses and the back EMF is often 20 times as high as the forward current was and it's this back EMF that is stepped up by the priamary:secondary turns ratio to be the 20KV+. You could probably work with 8 to 10 amps and not destroy the coil. To do this you need a small load resistor in series with the coil to generate a voltage proportional to the current. This is use as part of the feed back through either a comparator or amplifier to then limit and hold the current at a preset value. There is a circuit in Ed Lansinger's article in #63 October 1995 Circuit Cellar Ink. Alternatively you can go capacitor discharge. This is far more complicated and there are a number of different ways to do this. The most common is a high frequency oscillator that chops the 12V DC and creates a square wave that is stepped up through a transformer to produce 200V to 400V which charges a capacitor. The amount of current delivered by this power supply at 400V must enough to charge the capacitor within the time from discharging it the last time to when it needs to be discharged again; for a 4 cylinder engine this is 180 crank degrees at max RPM. Once the ignition point is reached in the engine cycle an SCR or TRIAC or ALTERNISTER is used to discharge the capacitor into the ignition coil. The advantage of a CD ignition is that it usually isn't dependant on battery voltage. There are some other ways to generate the high voltage but in each case the transformer/inductor design is the difficult part. Regards, John >Date: Wed, 25 Aug 1999 16:27:16 +0200 (MET DST) >From: Fredrik Skog >Subject: Igniton coils > >Hi! > >Can someone please enlighten me in how to decide how much current I can >put into my coil. I have a coil from a Alfa Romeo 155 and it is of the >waste-spark type. It has a primary resistance of 0.9 ohms. >I think I have wasted one coil already due to my lack of knowledge. I just >pumped 12 volts into it and it sparked a few times but then went dead. >I have one more but I don't want to kill this one too. >Do I have to know what voltage the Alfa puts into the coil to know this or >can I calculate/guess what it is in some way? > >Any help is greatly appreciated. > >Thanx! ------------------------------ Date: Wed, 25 Aug 1999 21:14:44 -0400 From: "crash70" Subject: Integrating Saab (bosch LH) and VW knock sensing ignition I'm a new guy here, so forgive my ignorance. In an effort to provide myself with a low-cost fuel injection system, I am attempting to fit an LH system from a 1986 Saab 900 2.1L 16v (non-turbo) onto a 2.0 16v VW engine. I have a complete CIS-E setup, but I don't like the restriction of the meter plate. Next to a MAP sensor, a hot-wire sensor seems to be the least intrusive method of measuring an engine's incoming air. Also, I plan to supercharge the engine later. I have all the components necessary to build this system. I have obtained a schematic of the fuel injection system, and came across one problem. I'm not sure if I can use my VW knock-sensing ignition with the Saab ECU. My main question is, will the pulse signal from the VW hall unit be ineffective to my ECU? The Saab ignition uses a pulse amplifier. According to the schematic, the input signal ranges from 6.5 to 8v. I hope somebody has some experience in this department to help me out. Once I finish the harness, I plan to "bench test" the system by mounting the hot wire sensor on my car (in-line with the CIS system) and installing the coolant sensor and ignition (if it can be done--hopefully somebody will advise me on this). Then, I'll check for proper injector duty cycle operation with my DMM. Once I get the system up and running, the parameters will be changed as necessary on the EPROM. I'm assuming the parameters will be in the ballpark, since the Saab engine is so close in displacement and volumetric effieciency as the VW motor. Any advice/comments/criticisms/thoughts/etc. are welcomed. Thanks! Chris Bishop ------------------------------ Date: Thu, 26 Aug 1999 12:13:58 +1000 From: Dave - M+H Melbourne Subject: VW intake Hi all, Does anyone want to buy mild-steel or aluminium (CNC laser cut) VW head (intake) flanges for making EFI/carb manifolds? I am doing a run soon (Type One and Four) - email me directly OFF LIST if you are interested. Yours EFI'ly, Dave - -- +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + M+H Power Systems Pty Ltd AUSTRALIA + + Batteries: Gel/AGM/NiCd/Wet Ph: +61 3 9763 0555 + + Chargers DC-DC Converters Fax: +61 3 9763 0577 + + UPS Battery Testers http://www.mhpower.com.au + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ------------------------------ End of DIY_EFI Digest V4 #489 ***************************** 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".