I do enjoy a challenge. Taking on challenges does result in failures. Failures are humbling. Good for the ego. Keeps it in its place.
A huge factor in meeting the challenge of automobile repair is staying within a budget. When your mechanic takes on the job of fixing your car there almost always is a budget. Nothing feels worse than blowing the budget and the vehicle is not repaired.
Sometimes the budget is just too small and even attempting a diagnosis and repair is just a waste of the customer’s money and the mechanic’s time. Intermittent problems can be like that.
The first part of any diagnosis is to reproduce the symptoms. If it takes more time (money) than the allocated budget to actually reproduce the symptom failure is guaranteed.
Nobody wins in this scenario.
“Once in a while it feels like it is just not getting the fuel. Must need a fuel filter or fuel pump or something. How much will that cost and how long will it take?” Without a whole lot more information that question cannot be answered.
A feeling of not getting enough fuel is not much to go on. The internal combustion engine (ICE) requires air and fuel in the proper proportions for your car to run smoothly and powerfully while using the least amount of fuel possible. Electric vehicles are another story.
A feeling of power loss (the car just won’t go like it usually does) can be the result of many different scenarios. If the engine can’t get enough air in there is no amount of fuel that will make it go. The engine is a mechanical air pump. Anything that prevents the engine from inhaling and exhaling the correct amount of air will limit its power. Air filter, air intake system, intake and exhaust valves, variable valve timing control system, pistons, connecting rods exhaust manifolds, catalytic converters, exhaust pipes, mufflers are all part of your engine’s breathing system
If the correct amount of air is getting in then only the correct amount of fuel will make it run properly. The supply of fuel has to be available as designed. It has to be the right type of fuel at the correct pressure. Delivery of this fuel into the engine is controlled by an electronic computer control system that turns on and off fuel injectors as well as controlling the fuel pump and fuel pressure.
The electronic control system uses a multitude of sensors to determine how long to turn the fuel injectors on for, thus attaining the correct air and fuel ratio. If your vehicle is a gasoline engine, not a diesel, then there is another system required to ignite the mixed air and fuel. This is the ignition system.
Ignition systems have spark plugs, ignition wires, ignition coils, and knock sensors.
So that feeling of not getting enough fuel, can be not getting enough air, or not getting enough spark as well. Even narrowing down the basic system that is at fault can take significant diagnostic time.
Changing the fuel pump or fuel filter on a hunch could easily be a waste of time and money.
Trail’s Ron Nutini is a licensed automotive technician and graduate of mechanical engineering from UBC. E-mail: firstname.lastname@example.org