There are 3 points of wear on the throttle body:
- the pair of bearings that guides the shaft of the throttle activating cam
- the bearings for the throttle butterfly pins
- the working side (vertical face) of the throttle activating cam.
Proper maintenance is to put, once a month, a drop or two of oil – I use Gunk spray motorcycle chain oil on the bearings and a wipe of grease on the side of the cam.
The rear section of the butterfly housing will gradually accumulate a coating of blow by, which enters at the vacuum nipple from the breather hose. Remove the air filter; put a brick on the accelerator pedal to hold the butterfly valve in full-throttle position; and spray the inside of the butterfly housing with carb spray. The first tine you do this, it will be necessary to work the deposits with a stiff toothbrush and then carefully work them out with a heavy-duty kitchen towel. There are sharp edges inside the housing; doubtless, small slivers will be cut off the toothbrush. Be sure to remove all slivers with your paper towel to prevent their being sucked into the induction tract. Spraying the inside of the throttle housing – the butterfly in full throttle position – once a month thereafter should keep it clear of blow by.
Each time you clean the inside of the throttle housing, allow the carb cleaner to dissipate. Then put two drops of oil at the joint of the lower butterfly bearing and, after removing the cap at the top of the throttle body, on the upper bearing. Replace the cap and tighten its two screws. Remove the brick. Work the full range of the accelerator pedal 5 to 10 times. Then reinstall the air cleaner.
Do not use WD-40 to lubricate the 2 pair of bearings. Although it will provide protection against bearing wear, WD-40 attracts dust, which snafus the idle-—it drops and remains down, or it hunts. The dust may also contribute to Co variation. The Kugelfischer pump has its own peculiarities at idle; don’t add to them.
EDITOR’S NOTE: The following articles were originally developed for the Tii Register Newsletter in the 1980s by several subject matter experts. I have edited some of the original copy to reflect things stated 20 years in the past, so you as the reader don’t have to guess what year it was written in 
If you ask a Tii owner what he likes best about his car, he is likely to tell you, “the engine and the cars overall performance”. While the car has a number of features that differ from the 2002, the most outstanding difference is the engine. It’s interesting to realize that until BMWNA decided to import the E30 M3 in 1988, the Tii was the most powerful 4 cylinder BMW ever sold in the USA. Even by today’s standards of electronic wizardry, a properly tuned Tii is a delight to drive with excellent throttle response and enough power output to embarrass many cars you happen to meet.
The Tii’s fuel injection system is the most important factor in achieving this level of performance. This key system functions around a small, 4 cylinder mechanical pump that goes by the unusual name of Kugelfischer.
The following information will attempt to provide an overview of the Kugelfischer pump as it’s used on the Tii, dispel some of the misconceptions about it and suggest ways to live with it happily for many years. We hope you find this overview interesting and helpful.
A BIT OF HISTORY
The pump takes it name from a large German industrial group with the overpowering name of: FAG Kugelfischer Georg Schafer AG. The firm is best known as Fischer AG and the initials “FAG” is used as the trademark for their extensive line of precision ball and roller bearings.
The company is headquartered in Schweinfurt and if any of you are students of the 8th Air Force in the 2nd World War, you’ll remember some very famous air raids over Schweinfurt to destroy Germany’s ball bearing industry. I’ll give you one guess who we were bombing! The name Kugelfischer appears to be their telex abbreviated name – a contraction of the name “Fischer” and the German word for ball bearing.
The plant that has built the pumps for a number of years is located in Munich at Truderinger Strasse 191. I am not sure if “FAG” owned “Schafer Einspritztechnik GMBH” from its inception; but they did own and manage this firm as a subsidiary until 1975, when FAG sold the business to Robert Bosch GMBH.
The original company probably had its origins in the aircraft industry that grew up around Munich, beginning with the First World War. They probably had strong business connections with BMW through their massive aircraft engine production programs from the mid 30’s through the 2nd World War. Kugelfischer has built a wide variety of injection pumps for diesel and gas engines over the years and many of these pumps are still in use all over the world.
Bosch continues to supply Kugelfischer pumps and parts but has de-emphasized the use of mechanical injection systems for gasoline auto engine applications. The pumps continue to be used extensively for high performance racing applications such as the BMW M1, in Super Vee and in some of the Porsche Turbo models. The Munich pump plant is used as a fuel injection component fabrication facility by Bosch. It may be only a coincidence, but BMW stopped using the pump about the time that Bosch bought “Schafer Einspritztechnik”. Part of the reason for the change has to be the flexibility of the Bosch “K” and “L” low pressure systems and their better adaptability to tightening emission requirements.
Bosch has continued to maintain service facilities here in the United States and to supply parts. The service is not as energetically supplied as it is with the pure Bosch systems, but It is available. Several injection repair shops go direct to Germany for parts and can supply exchange pumps and special units such as the Turbo pump with fuel enrichment control based on boost pressure.
BMW produced 64,177 vehicles using the Kugelfischer a 6 year period from December 1969 to September 1975. The M10 4 cylinder engine was installed in several models ranging from the 2000 Turbo, the 2002 Til, to the 5201 (E12) which ended its production run using the K Jetronic system.
History has also shown us that the Kugelfischer pump is a well proven design that will function for 100-150,000 miles without problems, given clean, dry gasoline and adequate lubrication. It makes an excellent car unique – and as such, worthy of preservation.
As part of the conversion of the register’s knowledge into a more “virtual group of owners” in the 21st Century, Bob and I have been working together to republish all of the original information published in two decades of newsletters and also much of the hard to find original BMW NA documentation. We have released the video and the book, “The BMW 2002 tii Fuel Injection System”, which has been only available in hard copy and VHS/DVD to Register members and BMW dealers in North America. These were originally developed by BMW North America for its dealer network in the early 1980s.
There are two parts you need to review – VIDEO and MANUAL. See below.
VIDEO
Example: Click links below to download the video.
The video is complimentary to the manual and can be viewed on any computer with the proper viewer – Quicktime from Apple for the low res (may work for dialup users) or the largest file (DSL or higher). Unfortunately the original audio is originally a bit distorted – converting to the web magnifies the flaws of the audio more. Click below to view the video in your browser. (Note, Windows users can right click and save the file to your local drive)
Quicktime – Low Resolution (11mb)
Quicktime – High Resolution (28mb)
MANUAL
The pump manual is in PDF format, 29 pages.
The manual is over 22mb Acrobat PDF file in length, but contains the vast majority of information previously known to dealers and pump subject matter experts. Of course, this is not a step by step to rebuild your pump by any stretch of the imagination – that still takes experts with the right tools, parts and test equipment. However, this does answer the majority of questions asked by Tii owners and prospective owners when it comes to the Kugelfischer pump.