BMW 2002ti Carburettor Tuneup To Fix Excessive Black Exhaust Smoke
Wow! Not every day we get to see an oldie like this – BMW 2002ti in all its glory!!!
Our client contacted us to find the reason why his car was spewing out excessive black smoke from the exhaust. He also requested we tuneup the engine.
Important to note this BMW model was first released over 50 years ago in 1968. This is way before any form of electronic diagnosis equipment had been invented. So this was down to good ole fashioned mechanics!!!
The first thing we did was to fit two new air filters to the Weber Carburettor side draughts.
We then proceeded to test the exhaust gases by inserting a CO gas analyser probe into the exhaust pipe. All exhaust emissions are made up of various gases including: carbon dioxide, water vapour, nitrogen oxides, carbon monoxide, sulphur dioxide, particulate matter (PM), and various hydrocarbons, including polycyclic aromatic hydrocarbons (PAHs) and other volatile organic compounds. We needed to determine the exact ratio of the gases in order to make the necessary adjustments. The old adage is important – You can’t improve what you can’t measure!
This testing showed the fuel/air mixture was far too rich. We needed to reset the ignition timing and the points. Each Weber carburettor has an Idle Speed screw and a Mixture screw and we adjusted these to set the ideal engine running condition. Essentially the carbon monoxide is set to 2,5 and the hydrocarbons to 200-400ppm.
Needless to say, in modern vehicles, the technology sets and monitors these parameters automatically.