When Your Car Won’t Start – Part 3

We have all had that sinking, sickening, aggravating feeling when we turn the key and nothing happens. Or we hear clicking, grinding, or other disturbing noises.  In any case, the issue is simply this: the car won’t start. In the last article, we talked about the essential factors for making a car run. In this article, we will examine fuel and what causes fuel problems.

The Basics

Photo by Fancycrave on Unsplash

First, an engine needs fuel. Plain and simple. Vehicles require a fuel like gasoline (petrol), E85, diesel, racing fuel, or even used cooking oil (yes, a diesel can actually run on used cooking oil). So, you are probably saying, “duh, I know that.” So, let’s look at the fuel itself first, then we will look at reasons why the fuel might not be reaching the engine.

Wrong Fuel

Not every type of gasoline is the same. There are different grades of octane. Some vehicles are extremely picky and require premium grade gasoline only. Some older cars actually do poorly with higher octane gas since it may damage older types of engine parts.  So the first thing to do is ensure you are using the right type of gas for the vehicle. This may seem obvious, but I had a friend whose sixteen-year-old son put E85 in a non-flex fuel car and it ran, but very poorly.  So make sure no one put the wrong fuel in the tank.


The vehicle may also run poorly (or not at all) if there is any water mixed in with the fuel. This can happen if there is a hole in the filler tube or other way for rainwater to get in. It is possible that going through flooded areas can allow water to get into the fuel. If this occurs, you will likely need the help of a mechanic. So don’t count out the possibility of water.  But that is assuming the fuel even gets to the engine.

Fuel Pump

Generally, fuel is delivered to the engine via a fuel pump. This can be a mechanical or electric fuel pump. Sometimes the fuel pump (an actual fluid pump) is inside of the gas tank. It can also be inline, usually close to the gas tank. Fuel pumps can break down. When they do, they will not be pumping fuel into the engine, so, the car won’t start.  If you have an electric pump, listen for the telltale whir of the electric motor as you first turn the ignition key.  You probably hear it all the time, but don’t pay attention to it. But if you don’t hear it, that could be the problem.


Finally, besides a break in your fuel line or a crimped tube (due to a misplaced car jack), another place where gas gets stopped is at the fuel filter. There is a fuel filter inline between the tank and the carburetor or injectors. This filter can become clogged over time, or if some contaminants got into the tank. The cure for this is pretty simple, just change the fuel filter. But, that might not be easy. Sometimes the fuel filter is in a place that is dang near impossible to get to. Once again, you may need to take it to a reputable mechanic.

So that pretty much covers issues with fuel that can cause an engine to fail to start.  Next time, we’ll cover spark plugs and coils.







Written by Gary Pradel