Written by Randy Gerdin on March 1, 2017
We have a fantastic client who has many different cars and trucks. The other day he brought in his 1941 Cadillac, a very, very nice car. This vehicle has a unique style that you just don’t see anymore. Of course, it has the “40’s” look. Wide white wall tires, long hood, rear fender skirts, lower front end, and distinctive passenger compartment. The car, of course, has running boards, and yes, there is real wood in them. He purchased the car and was working on it himself. It needed a front-end alignment and was also running poorly. The suspension and the engine were not original to the car, so he had to special order a number of the parts in order to complete this project. We got the front-end set up and went to work on why it was running so poorly. He had already replaced a number of the fuel system components and wanted us to install the ignition components. After we installed them, it still ran poorly.
Well, I am the “old” guy around our shop and even this car was made before my time. The technician that was working on it had installed the parts, but had limited experience with how to set everything up. So we dug though the shop and found a timing light, tachometer, and dwell meter. I used to use these tools daily, but had not had the call to use them in years. Also, my eyes are not what they used to be, so that is another challenge, but we started in. I knew what to do, but was unable to see some of the finer items and really had a hard time setting the gap on the points, etc. So, it took on a tag team effort, an old mind and someone with good eyes.
After messing with it a while, I felt the engine was running lean, the carburetor was not flowing enough gasoline into the engine. We knew the fuel supply was adequate, so the problem had to be inside the carburetor. The owner had purchased and installed a new carburetor, so it should be good. We pondered for a while, tried a few tricks I knew from years ago, but no luck. So we started to take the carburetor apart. It had been many years since I had one of this particular model carburetors apart, so I was remembering as we went. We took the front bowl cover off and found that there was a bunch of rusty looking crud in it. We figured if that stuff is in the bowl, then it probably is everywhere else inside the carburetor as well. We cleaned it out, removed the fixed jets, and cleaned everything we could.
Putting it back together was another chore. There are multiple items that need to line up correctly while the gaskets and O-ring must stay in place. After a couple attempts, we finally got it together with no leaks, but it still ran poorly. I had to take a phone call and when I returned, the car was running well. I asked what he did and he said he tried one of the old tricks I knew and it worked. We adjusted the idle mixture and idle speed, and down the road it went. It was then on to the next job sitting in the adjacent stall.
This was a late-model pickup with an engine misfire and an unusually loud engine noise. And I mean LOUD. We were about to condemn the engine, but a few things did not add up for us, so we kept working to find the root cause of the problem. After some research, a few phone calls, and a little investigation, we found the engine fuel management system was part of the issue. In this engine, the computer uses engine oil and a solenoid to shut down the engine lifters on four of the cylinders during certain situations to save fuel and improve emissions. In actuality, it turns an eight-cylinder engine into a four-cylinder engine. The computer also will shut down the corresponding four fuel injectors. We found when we used the scanner to manually shut down the system, the loud noise went away. What a difference from the old 1941.
We were using computers to talk to other computers to diagnose internal engine systems. We had not experienced this in the past and I hope we will never forget this one either. Fixing cars is a lot like the rest of life. We live and learn from our experiences. Hopefully, we don’t forget them. I Hate When That Happens!