One of the few real contributions I have been able to make to the MkI VW community, who have helped me with countless problems, is a manual for repair and replacement of MkI convertible tops. Co-Authored with Brian O’Connell of the152, it will save your bottom end when leaks invariably wander in.
It’s one of my favorite literary lines ever, from Michael Crichton’s The Andromeda Strain. The scientist in question is pondering whether successful treatment of the symptoms displayed by his patient means that the disease causing them is actually cured.
So it goes with electronic diagnoses involving logic boards. Stray voltage at one pin results in a strange signal at another one. The voltage can have three sources, but which one is it?
For example, a artificially high (500rpm) tach reading on an F650GS that remains after shut off for several seconds. Coupled with poor running/starting. Symptoms occur only when bike is started wet after cold rain. Brought up to running temp and restarted, the problem is gone. Signal path is a single star circuit of the ECU, the #1 coil, and the tach signal feed. Diagnosis starts with check air and fuel to rule them out for the poor running aspect. Both are fine. Second step – pull plugs. As expected the #1 plug is funny looking, not bad, but a bit pink on the insulator. The primary resistance on the coil is a hair high when the coil body is wet.
Is this a symptom, or is it the disease? I’ll find out when I pull the tach apart. I hope.
All my life, I’ve been pretty good about patents and trademarks. So I’m a bit confused as to why BMW isn’t. The “Motronic” in my bike is actually a Hella product called BMS, as I just learned from the FAQs over at f650.com. This explains a great deal about why it bears so little resemblance to a modern Bosch engine management system, even as it bears resemblances to pieces of so many others.
Did I say anything about wanting to learn a new EFI control codec? No, I did not.
edit – when I wrote this post, I was under the impression that Motronic meant Motronic. Not to BMW, who call any engine control unit Motronic, regardless of whether they are violating Bosch’s trademark rights or not… See above.
I am a card-carrying K-Jetronic girl. When I first discovered K-Jet-E in my 1982 VW Rabbit Convertible, I leaned back in awe and remarked to myself that this is how I would do fuel injection if I had to: I would take apart a carburettor and distribute its parts liberally around the engine bay, making sure that each had its place and did not interfere with the others, all being individually adjustable and controllable (einstellbar und kontrollierbar, auf Deutsch). Just like K-Jet. I regard K-Jet as one of the peaks of elegant engineering design, and certainly one of the coolest systems to ever leave the halls of Robert Bosch Gmbh. It is also simple and easy to work with, provided you understand the basics of air/fuel ratios and a few other odds and ends about ICEs, of course.
I can’t say the same for Motronic, Bosch’s “modern” EFI control system. I’ve been watching a weird problem on my bike lately, and I’ve tracked it down to what looks like a bad hack job over in the Motronic design group. Not content with just supplying a modern, 2004 version of Motronic, it appears that Bosch decided to crib together the lousy parts of Motronic (signals taken from only half of the system), an interesting part of K-Jet (running the whole thing off the coil sense), and who knows what from Digifant.
The problem manifests itself as a flat 500rpm lift in the tach signal when it rains. Being Motronic, the tach signal is fed from the coil sense, but only from one of the two coils. The Rotax engine is known for some assorted issues (other than being a bullet-proof, workhorse, dinosaur of a fuel-efficient and otherwise great motor), one of which is pretty serious surging. Well…. imagine that. When your injector circuit is being driven by a feedback loop from half of the coil circuit, and voltage is building up due to phantom capacitance somewhere, yeah, the poor thing is going to surge like crazy.
So, I’ll be spending my weekend working on the bike with the only tool you need on a Motronic machine: my DVM. This is not what “working on the (insert ICE-equipped vehicle)” is supposed to mean, Mr Bosch…..
Much more important than people realize, your tyres are riding on this wire…
From my presentation to the Wire Association International in 2004. Still the most wonderful, talented group of engineers I know.
Lubrication in steel wire drawing operations generally brings soap powders to mind. For larger wires this is uniformly the case. The soap powder melts in the wire/die interface and provides a viscous film that supports the drawing force. The fillers and additives in the drawing soap impart polishing, extreme pressure, and many other properties to the lubricants. As wire sizes get smaller, the soap powders become unsuitable for high performance drawing. The viscosity of the molten film is too high, and the film occludes the hole, reducing the wire diameter and eventually breaking the wire. Additives may corrode the wires causing breaks. The polishing aids and other particulate materials may be drawn into the wire, weakening it and resulting in failures. Wet drawing lubricants are required to overcome this problem.
Wet drawing lubricants are based on water and/or oil and have considerably lower viscosities than the molten soaps they replace. This reduces the film thickness and the chances that the film will occlude or block the die orifice. Wet lubricants do not contain particulate materials, so foreign inclusions are not drawn into the surface from the lubricant. The additive level is much lower in a wet lubricant and can be controlled by dilution. The wet lubricants also provide cooling to the operation, a feature absent from dry drawing operations. The wet lubricant requires different maintenance techniques than those required for dry soaps. A comparison of the two types of wet lubricants and their individual requirements for usage will be presented.
Abstract from my 2004 presentation to the Society of Tribologists and Lubrication Engineers….. Probably one of the best papers I have ever given, and winner of the Deutsch award for practical tribology research. That was a big day for me!
Predictive testing of Steel Rolling oils using the Elastohydrodynamic Lubrication Rig
The rolling of steel sheet from continuously cast slabs and coils or ingots to sheet and tin products is a fundamental step in the manufacture of goods worldwide. Slab and sheet reduction is accomplished by plastic deformation of the slab using large metal rolls to apply a force normal to the slab. The contact area between the roll and the slab/sheet must be lubricated to provide proper sheet finish and good tool life. Rolling operations are very large, and it is difficult to test the performance of rolling oils on the mill due to the volume of lubricant and the set-up times required. Development of reliable predictive testing methods is critical for the design of good rolling lubricants.
Rolling oils are typically formulated from fat and mineral oil basestocks with appropriate additive packages and provide hydrodynamic and boundary lubrication to the roll contact. The rolling contact is formed by the plastically deformed sheet and the roll and has three specific zones – the backward slip zone, the neutral point, and the forward slip zone. In both of the slip zones, fresh metal surface is exposed and the process operates in a slip condition. At the neutral point, the contact operates in a true rolling condition. This suggests that a test method with variable slip is for testing and evaluation of rolling lubricant performance.
Two smallish pillions got their first rides today. No panic attacks, no disasters. Two future riders? Who knows….
There will be new content interspersed with old content for a while…
It’s weird to do car diagnostics from no where near the car. Email diagnostics were taken to a new level with one of the old Golfs – a Brasilian Golf IV TDI that had massive electronic issues. After throwing parts at it for two months under warranty, I called in the help of a trusted friend and VW tech, emailing the longest list of codes I had ever seen: 174 in total. The solution, according to the friend, was to search every ground lug in the car out, and check it. This is a seven hour job, and the dealer was not interested until I threatened to lemon the poor car. I did not want to do that, but hey, it worked. The culprit ended up being a $1.50 acorn nut that was loose on the ground point under the battery. For nine more years under our ownership, the car went without a single problem that could be traced to bad electronics. Actually, it went without any problem that could not be solved in an hour in the driveway, or a call to the warranty office. It was a good car, afterall.
I purchased my Passat in March of 2000 from Devon Hill VW in Devon, PA- they are good guys! I took delivery on the 24th, and I have been enjoying the ride ever since.
It is Indigo Blue with a grey velour interior. It has a five speed manual transmission with the 1.8 litre turbo engine. It came with the luxury package of a sunroof, rear tonneau, and Adelaide wheels (I like them!!). I also purchased the CD-6 changer to go with the Monsoon head unit. I got the CD-6 as a peace offering to my spouse since he wanted the Tip! I also have the VW roof rack crossbars.
My first mod was a customisation. I replaced the shift knob and boot with a gobKnob bubble ball and a custom boot which I made myself. I have a pattern and instructions for those who wish to make their own boots, too. The shifter shaft is an unusual thread- 12mm, 1.5 thread pitch, so you have to get a special tap! Dad machined out the stainless steel fitting which screws onto the shaft. I am planning a surprise *upgrade* for this spring to this knob system. Keep checking the forums at clubB5 for more on this!
2/01 – I recently swapped out the rear interior light for the switched version. This is the same reading light that is found over the rear doors in the cabin. The part cost $22, and the install took about 2 minutes. This is very nice for late night grocery runs with the kids- you can turn off the light and let them sleep!
4/01 – The AlienWindow remote window controller is an excellent modification to make to your car. It allows you to control the windows from your VW switchblade remote. I just did it, and it’s great! It took me about one and a half hours to get done and was a good afternoon project. I took some pictures of the install while I had the car apart.
5/01 – My Euroswitch has arrived from the Pottermen! What nice people out there in CA, they sent me M&M’s with the part. Order from www.parts4vws.com. I have installed it, now I must run the wires for my rear fogs. I also explored the underside of the dashboard – kind of a pain to get into, but there are many goodies underneath there! Including relay 173. I expect to be removing that soon, when I finally convert to clear corners and those fabulous PolarG blue bulbs!
Rear fogs are in! I had some trouble with the wiring, You must go up and over the hatch in the variant, something I did not anticipate when I soldered up my wiring harness. You need 20′ of wire, 13 feet from front to back, and 7 feet from side to side. I have caught some flack for wiring up both sides, but I think that it looks better. I am also thinking about slaving the brake lights into the fogs with the dual diode arrangement, so I need the wire over there anyway. I also hooked up the dash indicator. This was a bit difficult as I had trouble with the plug in the back of the tachometer. It was difficult to get out. But, done and over with, so I am happy.
I added the sunglass holder also this month. Unfortunately, the dealer was only able to get the Passat (3B0) part, so I am stuck with the chrome strip. It doesn’t look as bad as I thought it would in my otherwise chrome-free car.
I am a Organometallic chemist, and my chief interest is is the interaction of hetero-atomic molecules with transition metals, specifically copper, zinc, and iron. Hetero-atomic molecules are those that include atoms such as sulphur and nitrogen in addition to carbon, hydrogen, and oxygen. I like to examine the electrochemistry of the metal surface and how it changes when certain hetero-atomic molecules are brought into contact with it under a variety of conditions such as pressure, sliding and wear. I am particularly interested in the Extreme Pressure (EP) elements- Sulphur, Phosphorus, and Chlorine.
The boundary regime of lubrication is also of interest to me, specifically the area of the transition from Elastohydrodynamic lubrication (EHDL) through the Thin Film (TFL) regime, and into the Boundary regime. I hope to do a lot of work in this area one day. The research group in Mechnical Engineering at the Imperial College of London, headed up by Dr. Hugh Spikes, is a good place to start if you would like to learn more about this area of study.
I also like to investigate the oxidation of aluminum when I am not otherwise occupied