As a mechanic when you are out and about you inevitably hear the sound of a starter cranking over an engine that is refusing to start. If you are at the lake it may be a boat engine. If you are in a parking lot it may be a car or truck.
In most cases a long cranking starter is being abused. The engine is probably not going to run and the extended time spent with the starter working is only serving one purpose. It will either wear out the starter or more fortunately discharge the battery enough that the starter does not have to suffer any more abuse. That is until the inevitable do-gooder offers a jump start.
If only we all could be a little more logical. If your engine was always starting on cue and now it is not, there is a problem. Continuing to crank the engine over without attempting some type of logical testing and diagnosis is really serving no purpose but the inevitable demise of your starter and/or battery.
At this point I feel I must define the terms “cranking” and “starting” and “running”. They are often misunderstood.
In order for your vehicle’s engine to start running it must be physically rotated by an outside force at a speed quick enough to allow combustion to take place. This is cranking and it is performed by an electromechanical device called a starter.
When you initiate the cranking process while turning the key, pushing a button, or pulling the cord (lawnmower) you are attempting to start the engine. At a certain cranking speed combustion results when the air fuel mixture within the engine’s cylinders can self ignite (diesel) or ignite by spark (gasoline).
The ignition of the fuel/air mixture causes explosions within the engine that start it rotating on its own. Starting is the onset of combustion combined with the outside work of the pull cord or electro mechanical starter. At this point the engine still requires outside force to keep turning.
As the engine reaches a point where it will continue to turn on its own power it is running. All is well. Understood? I hope.
So as you turn the key to the start position (push the button or pull the cord) you should hear cranking. If the battery and starter are good the cranking should be fast enough to start combustion. If the engine just cranks at a normal speed longer than normal with no change in sound you have a problem that likely will not be solved by continuing in the cranking mode.
The engine is missing one of the prerequisites to initiate starting. These are the proper mixture of air and fuel compressed to a high enough pressure to be ignited by a spark (gasoline engine) or self ignited (diesel).
Instead of continuing to crank and crank and crank, stop and think. Do I have fuel in the tank (look at the gauge, unscrew the lid (lawnmower, motorcycle, weedeater))? Lift the hood. Is anything obvious in the way of letting air into the engine? What are the instrument warning lights telling me. Open up your owner’s manual. Is the immobilizer light blinking?
Yes, a little detective work is in order. I don’t want to have to sell you a starter and a battery before getting to the original problem.