Tuesday, November 10, 2009

"Elementary!" I Love A Good Mystery

Many times I have come across items on "Restored" cars that have been done incorrectly. How can you restore or repair something if you don't know what it looked like when it was new? If you don't know then you need to study the repair manual or employ what I call forensic repair, treat the repair like a good mystery. Study the problem and look for the clues. A clients "Restored" 1965 Porsche 356C was having a problem with fuel starvation. The mechanical fuel pump could not supply enough fuel to the carburetors. First I looked at the in line fuel filter in the engine compartment...it was installed backwards. In the photo below the fuel flows into the nipple on the left and the paper element keeps the particles from clogging the jets in the carburetors as the clean fuel flows out of the right nipple.(If you look closely you can see the arrow on the left end of the filter pointing to the right, showing the direction of fuel flow) But why would it matter which way the fuel flows through the filter? If the fuel flows the wrong way the particles will build up and get caught in the filter element like a coffee filter holds coffee grounds. When the fuel flows the correct way the particles are under the element and the constant supply of fuel keeps them suspended not clogging the filter as much. After I installed a new filter in the correct direction, the car was still having problems with fuel starvation. I wondered if when the car was restored someone put another fuel filter under the car? If one filter is good then two is better right? Not so. When I climbed under the car I found another filter and it was very clogged with rust particles, so much that the fuel could not get to the filter in the engine compartment. I replaced the lines and the filter that were under the car with one fuel line. The fuel filter is in the engine compartment for a reason...it is easy to service and visually inspect in that location. Once the filter under the car was replaced with one fuel line, the car ran fine. In this case the repair was not much of a mystery, because I know how the 356 fuel systems came from the factory. Some times the clues that you need are in the repair manual or even in a parts catalog, a quick look at a parts schematic for a 356 fuel system would have shown me how many fuel filters were needed. A little detective work is all that you need most of the time. As Sherlock Holmes said "Elementary", many times the most simple solution can solve a the most complex problem.

1 comment:

  1. This is great. You could take 50 of these mysteries and make a book.

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