How to Find the Right Diesel Injector Nozzle
Even a small thing like a diesel injector nozzle can affect the performance of your car. The lower the fuel mass an injector nozzle produces-or sprays to the cylinders-the less horsepower the engine has. But a more pressing problem when it comes to diesel injectors is the accumulation of carbon deposits in the injector nozzles. Even though there are four to six injectors in a car, the shortcomings of one clogged nozzle cannot be compensated by the functioning others. If your car has been hinting you of poor horsepower output, then it might be time to shop for new injector nozzles to bring it back to its giddyup speed.
What specs to check for: injector flow, hole size, hole number
There are three specifications that you should be aware of when buying new injector nozzles. These nozzles are rated using two numbers with a multiplier in between; the first number is the number of holes in the tip, while the second number is the size of the hole measured in thousandth of an inch in diameter. For instance, a 7x12 rating indicates that the nozzle has seven holes with each hole measuring 12 thousandths of an inch in diameter. This particular nozzle gives 55-horsepower, 275cc, and 91 pounds per hour of fuel mass. So, six fuel injectors can produce 220-horsepower, which is above that of a Ford Escort and 100-hp less that of a Mitsubishi 3000GT.
Which type to choose: pintle, disc, ball
There are generally three kinds of injector nozzle tip. The most common one is the pintle, which has a protruding extension through the hole of the nozzle's body; it has also been used for more than thirty years. Buy this type if you want greater fuel penetration into the combustion space. The disc type uses the same mechanism as the pintle, but it has a flat disc and a multi-holed plate. Choose this type for its good spray pattern, but its design does not prevent clogging. Opt for a ball type with a ball-and-socket design for its great spray pattern and atomization, but same with the disc type, it can be clogged by deposits.
How to Replace Your Diesel Injector Nozzle
A longer gas mileage is one important factor to make a happy driver. A car that consumes more gas in just a few miles of travel definitely sets off two alarms: one for component efficiency and another for your pocket. If you notice that your car's engine is performing unsatisfactorily, then perhaps your fuel injection system needs replacement. But before replacing the entire assembly, check first the component concerned with fuel combustion and emission-the diesel injector nozzle. This nozzle atomizes fuel by firing it a thousand times to the cylinders, so when this part becomes the problem, there is no other minute to spare. Don your handyman clothes and get ready for action!
Here are the tools you need and the steps you should follow when replacing your problematic diesel injector nozzle. Warning: Make sure that you work on a cold engine and on one injector at a time.
Difficulty level: Moderate
- Diesel injector nozzles (one for each injector that needs new nozzles)
- Sealing washers
- Heat shields
- Diesel or biodiesel (for cleaning)
- Socket set
- Wrench set
- Paper towels
Step 1: Raise your hood and remove the engine cover. Locate the injectors by tracing the fuel line connections from the outgoing line to the fuel filters and to the fuel pump. Note: Make a diagram of the connections if you have a hard time remembering them.
Step 2: Loosen the nuts attaching the fuel injectors to the engine. Grab each injector with the pliers and detach it from the engine. Be careful not to let dirt or grease get into the fuel lines. Place the lower half of the removed injector in a vise.
Step 3: Remove the retaining nut (the part that holds the injector nozzle against the injector's body) from the upper half of the injector. Clean the sealing washer and injector threads of any carbon deposits using the paper towels, the toothbrush, and diesel.
Step 4: Install the new nozzle on top of the now clean injector. Attach the retaining nut to the nozzle and screw them down together to 70 to 80 newton-meters of torque (or to what is advisable for your model).
Step 5: Clean the injector hole (the part where the injector is connected to the engine) of any debris and oil. Install the heat shield with the hollow part facing up. Then, install the injector and set it to 70 to 80 newton-meters of torque.
Step 6: Follow the same procedures for each injector nozzle replacement. Reattach the fuel lines and tighten the connections up.