Growing Your Diagnostic Skills
Growing Your Diagnostic Skills
Every tech has to start at the beginning. Here are tips to help you make the transition from general repair to drivability specialist.
Motor Age — We all had to start somewhere. No one was born a drivability expert, though some are gifted with a natural talent for reasoning through even the most difficult of diagnostic challenges. I, for one, was not so gifted and had to work at developing my diagnostic techniques. And if I can do it, so can you.
Don’t Be Afraid!
In days gone by, carburetors dumped a poorly atomized air/fuel mix into a common chamber in the intake. From there, the hungry cylinders drew in the mixture through the intake valve (each cylinder had only one) into the combustion chamber. A mechanical switch called “points” was used to interrupt the flow of current to the single ignition coil, and from there the secondary voltage was routed to each cylinder by a distributor rotor that was mechanically driven. The spark ignited the compressed mixture, and it exited through the exhaust valve. All the valves were opened and closed by a single camshaft. Not a lot to it but these early designs had one unique and common factor. They didn’t need a computer to run.
This is the vacuum transducer and is used to control vacuum flow to the EGR valve. Notice there are three vacuum lines attached and one electrical solenoid.
But they weren’t that good at utilizing the energy released during combustion either. Today’s engines are much more efficient, producing more power on less fuel than ever before. Computer controlled systems allow precise control of factors that impact efficiency. And often it’s that word “computer” that scares techs away from drivability issues.
Don’t be one of them. No matter how involved or complicated the technology might seem to be, it’s still an internal combustion engine (ICE) that needs compression, ignition and fuel in just the right amounts and at just the right time to perform properly. Sure, there may be more complex ways of controlling it all, but with a little thought, a good service information (SI) source, and a bit of continuing education, you can learn to adapt with the change.
A Foundation To Build On
Before you can tackle a drivability problem, you first must have a solid core understanding of how an engine works. No, you don’t have to have an engineering degree, but you do have to know more than “suck, squeeze, blow and go.”
Source: Motor Age
