Classic car repairs are more art than science

I have a friend - let’s call him Mike - who has an interesting collection of cars ranging from tiny two seater 4-cylinder British sports cars to large V-8 (426 Hemi) powered American Muscle cars. Somewhere in between these two ends of the collector car spectrum is a 1963 Dodge Dart station wagon equipped with Mopars’ famous straight-six engine and a “three on the tree” manual transmission. Other than a go-cart, there is probably not a simpler 4-wheeled gasoline powered vehicle on the face of the planet.

So it’s not so surprising that the car has been the epitome of reliability for the entire time that he’s owned it… right up until he decided to sell it. More specifically, the moment that he took a prospective buyer for a test drive. The car began to run rough and started to lose power, almost as if to say “Please don’t sell me.”

The test drive ended with a promise that the problem would be remedied before the sale was completed. This is not where the story ends. This is where the story begins.

Being an honest and diligent seller, Mike immediately began the task of determining the source of the problem. For some reason he began by replacing the distributor cap, which didn’t help. From there it was on to replacing the fuel pump and the ignition points. All to no avail. So he ordered a rebuilt carburetor, and while waiting for it to complete its trans-continental journey, he decided to replace the ignition wires. In doing so he discovered that all of the ignition wires were installed on their wrong respective spark plugs, so he felt certain that he had found the problem. Unfortunately, after re-routing the wires, the problem persisted. To this day I still don’t understand how it is possible, as the engine ran perfectly with all the wires routed improperly, and was still able to run after he had re-routed them. Finally the carburetor arrived, was installed, and problem…worse. The engine ran for 30 seconds and died. Did I mention that new fuel filters had been installed also? As of this writing this is where the car sits.

Those of us who have been in a similar situation with a classic car (and who hasn’t?) can feel Mikes frustration. Countless hours and lots of money have been spent with no benefit. Well, that’s not entirely true. When the problem is finally solved, the new owner will benefit from all of these new parts.

Collector cars are fairly simple. Mechanical problems of this nature will almost always fall into one of two categories: Electrical or fuel-related. Rarely do both contribute to a problem, especially when a car was running fine. One exception is a car that’s been in storage for a very long time, in which case problems with both systems are not un-common. But this was not the case with Mike’s car.

The same is true with modern cars in that most problems of this nature can be traced to electrical or fuel issues. With modern cars both systems are much more complicated, and diagnosis is aided by the use of onboard and diagnostic computers, which will often point directly to the problem.

By comparison, collector cars are fairly simple, and diagnosis is more of an art than a science. Often, diagnosis will begin with a hunch such as “It feels electrical to me.” Professionals and talented hobbyists can often tell the difference. And that is where the trouble shooting begins. But this is where Mike went wrong. The art of trouble shooting a collector car does not begin by replacing parts. In fact, this can make things worse. If you install a defective part, or change a setting, you could now have two or three problems, where before you only had one.

You must use your knowledge and your common sense to determine which system to explore. But most important of all, you must know your limitations.
If you operate the accelerator and you don’t see any gasoline squirting into the throat of the carburetor, you can be pretty certain that you have a fuel problem. Now it’s up to you to decide if you’re comfortable proceeding to check the carburetor, filters, fuel pump, and fuel lines for defects.

If you remove a spark plug and hold the electrode to a good ground on the engine block, you should see a good spark jump the gap when the engine is cranked. If you don’t, you need to decide if trouble shooting the points, ignition wires, coil, ignition switch, and all of the other possibilities is within your comfort zone.

If the only solution that you can come up with is to start replacing parts, I can tell you that you are out of your comfort zone. Whereas I always admire those who are willing to work on their collector car themselves, sometimes it just doesn’t make sense to do so.

Had Mike recognized his limitations, he might have had the car professionally repaired. I suspect that the cost would have been a fraction of what he’s already spent, and his frustration level would be zero. Most importantly, the new owner would be driving the car.