If oil is to your car what blood is to your body, then fuel injectors represent the main arteries to your vehicle’s heart - the engine. We all know what usually happens when those arteries get hardened or clogged - heart disease, stroke, and death.
What happens when your fuel injectors get clogged and break down? For starters, the fuel consumption on your favorite 2005 VW Jetta, which survived all those trips to Myrtle Beach, will increase dramatically. At a time when diesel prices sit at an all-time high, every penny’s worth of fuel efficiency counts.
In addition, your engine might stop working entirely due to damage caused by the bad injectors. In the long run, maintaining or even replacing your fuel injectors will prove infinitely cheaper than spending hundreds of dollars on wasted gas or thousands on replacing your VW’s vintage 1.9L ALH TDI diesel engine.
How Fuel Injectors Work
A diesel fuel injector pressurizes the fuel and pumps it through a tiny spray nozzle onto the engine, powering the vehicle. Because of its specialized construction, the fuel spray hits the engine in a perfect cone shape, allowing it to burn evenly across the engine surface. Your injectors should last anywhere from 80,000 to 100,000 miles if properly maintained.
You generally have as many fuel injectors as you have cylinders. A V8 engine, for example, would have eight fuel injectors. New and rebuilt diesel injector prices range from a few hundred dollars to several hundred dollars a piece, depending on the type of vehicle and engine you have, so it makes sense to do everything you can to keep them in the best shape possible. For more on that, be on the lookout for our next article, “5 Handy Tips for Keeping Your Fuel Injectors Up to Speed.”
What Fouls a Fuel Injector?
As a premier diesel parts supplier to customers across the nation, we have heard our fair share of fuel injector horror stories. Typically, injection systems have three main enemies: Fuel or dirt build-up, water, and air.
As your engine burns fuel, it can leave oil and carbon residue on the engine surfaces and the injector nozzle. As these materials build up, tiny bits of debris can break away during the injection process and derail your fuel spray pattern. The use of sub-standard diesel fuel can also introduce dirt and debris, as well as water, into your fuel system.
Water can get into your fuel through humidity changes as the weather fluctuates or if you have a leak anywhere in your fuel system. Finally, when you allow your tank to get completely empty, it will take in extra air; if there’s too much, your engine will have a hard time starting.
Heed the Warning Signs
Again, much like your body, your car or truck will often give you danger signals when it’s beginning to malfunction. Our fuel injector pros suggest that if your vehicle experiences any of the following five symptoms, it needs an injector check-up, pronto.
1. Fuel Efficiency Plummets
Have you noticed you have to fill up your Ford F-150 more often? Faulty fuel injectors can dramatically reduce your vehicle’s fuel efficiency, though it may not happen quickly. When you begin to see the miles you get for each gallon start to spiral downward, it’s an excellent time to run a diagnostic of your fuel system.
2. Hard Starting/Engine Misfires
When you have to crank the engine several times to start your vehicle, that is called a hard start. It takes several tries to get your engine to finally turn over, if it even starts at all. An engine misfire sometimes referred to as a throttle hesitation, happens when you press on the accelerator and your engine stumbles or skips before propelling forward.
3. Rough Engine Idling
Your vehicle does not idle at a steady rate after you start it, and you feel like it could stall at any moment. The RPMs may also fluctuate, like when you rev your engine, even though you are not pressing down on the accelerator pedal. Your vehicle should normally idle smoothly at a steady rate of about 1,000 RPMs. You have a problem if the indicator is dancing all over the dial.
4. Exhaust Smoke
A correctly functioning engine will take fuel, burn it, and emit clear carbon dioxide and water. When you see smoke coming from your exhaust, whether black, white, or blue, it means your engine’s air-to-fuel ratio is off. Either the engine’s pumping too much fuel or your fuel system isn’t getting enough oxygen. As a result, your engine burns fuel partially or inconsistently, spewing environmentally unfriendly gasses such as unburned raw diesel and half-combusted fuel carbons into the atmosphere.
5. Fuel Smell in the Cabin Interior
A lingering waft of diesel on your hands after you climb back into your truck is pretty normal, but if that fuel odor grows stronger and lasts longer, it could mean you leak somewhere in your fuel injection system. One or more of your injectors also could be releasing fuel through the nozzle when it’s not supposed to.
Any of these symptoms spell trouble for your vehicle, so getting them checked out is critical before anything seriously awful (translate = expensive) happens to your engine. And if you do find that your injection system has fallen ill, don’t fret - we have been the ultimate injector pump rebuilders in the business for years and have everything you’ll need to get your fuel system and your car back on the road.
