Have you ever been in a hurry to get somewhere and then floored it on your Nissan 350z but somehow the power that was once there is nowhere to be seen now? It can be quite frustrating to experience a loss of power in your 350z, considering it is a sports car. However, this problem is more common than you think.  

The power output of your vehicle changes slightly over its lifetime due to various reasons including wear and tear and carbon deposition on the pistons. This can lead to both a decrease and an increase in power. However, an overnight loss of power in your Nissan 350z may occur due to several reasons such as problems with the airflow, injection systems, and sparkplugs. Other reasons such as using the wrong fuel, sensor problems, and even a worn clutch may lead you to feel a drop in performance over time.

Time to dig deeper into these problems and see possible solutions for them.

Fuel problems

A very simple but common problem that causes a dip in performance is changing the fuel. This typically happens if you end up purchasing fuel across borders or at a different vendor. The percentage of ethanol blending is something that can affect how your car performs.

Alternatively, if you are used to running your car with premium fuel (fuel with a higher octane rating) you might experience a dip in performance when you go back to using normal fuel. Thus, you may want to switch back to your usual vendor to see if the fuel problems are resolved or not before you move on to troubleshoot the other problems.

Airflow problems

One of the simplest causes for a loss of power in your 350z is a fluctuation in the amount of air supplied. When not enough (or too much) air is supplied for the same quantity of fuel, then there is a chance that the air-fuel mixture ends up too rich or too lean. In either case, you might face a loss in power as the engine only operates at optimum levels if the ratio is as close to ideal as possible. This deviation may occur due to the following reasons.

Clogged Air Filter

The air filter is responsible for ensuring that dirt and other particles from the road do not get into the combustion chamber and further reduce the power output. However, over time, these filters tend to get clogged up thanks to these very particles. Thus, you will often see that the mandatory service checks recommend changing (or cleaning) the air filter.

Fortunately, the solution is simple, and one just has to clean or replace this filter. You can clean the filters with a portable vacuum cleaner too to some extent. This should immediately increase the airflow and return the lost power. If not, then you should probably check out the next point.

Throttle Valve

The throttle valve controls the amount of air that flows into the engine depending on the driver’s demand. Unfortunately, either due to a mechanical failure or a calibration error, the throttle valve doesn’t open as much as it is supposed to. This may result in a loss of power as a suboptimal volume of air is sent to the engine. It can be fixed by recalibration of the throttle body or replacing it. You may have to go to a dealership for the former, but the latter you can do at your own home!

Throttle Valve Position Sensor

This particular sensor communicates the position of the throttle valve to the ECU. According to feedback from other sensors, the position may thus be changed based on requirements. However, a malfunction may lead to the ECU getting wrong data on the position of the valve and thus an inaccurate correction may be made. The solution in such a case would be to simply replace the sensor.

Injector problems

Like a restriction in the airflow, problems with the fuel flow may also result in a loss of power in the 350z. The reason for this is the same that the fuel mixture may end up too lean or too rich. Time to look at what may cause these problems.

Injection Timing

As the title suggests, it is the precise time (or angle) at which the fuel is injected into the manifold to mix with the air and then proceed for combustion. The timing is extremely important as it determines how well the air-fuel mixture is formed in the engine. Injecting the fuel too early or too late may not only result in a loss of power but also an increase in fuel consumption. This is due to the possibility of a lot of fuel leaving the cylinder in an unburnt state.

Generally, wrong injection timing is a result of some issue in the ECU. So a soft reset like restarting your car should fix the problem. You could also try to disconnect and reconnect the battery after a while to reset the ECU. If neither of these techniques works you might want to get your car checked at an authorized Nissan dealership as it may require some re-calibration.

Dirty or Clogged Injectors

Due to the position of the injector, carbon and other debris tend to form around the injector nozzles and block the fuel from being sprayed properly and effectively mixing with the fuel. This need not be the case for all cylinders and injectors, but it may explain the loss of power to an extent. You may want to get the injectors cleaned to resolve the problem. While this may be a bit difficult to do at home, it is easier to change the injectors themselves.

Malfunctioning sensors

The amount of fuel to be injected is calculated based on the driver’s demands, the amount of airflow, and based on feedback from sensors in the exhaust. If either of these sensors (Mass Air Flow or O2 sensor) are malfunctioning, then the injector gets the wrong information on how much fuel to inject. Again, a suboptimal amount leads to suboptimal power output. These problems can be resolved by replacing the concerned sensors.

Spark plug problems

Like the injection system, the ignition system may play a role in the lack of power as well. Here are a few sparkplug issues that may result in your car not winning the race.

Spark timing

As the pressure inside the combustion chamber is constantly changing, the moment the sparkplug lights the air-fuel mixture on fire is very important. Depending on the timing, the heat output changes thus affecting the torque and power of the vehicle. Thus, if the spark timing is wrong, you may experience a loss of power in your Nissan 350z too. Fortunately, the fix is just as easy as the one you saw for the injection timing problem. Repeat the same steps and you should be back to winning the race in no time.

Sparkplug gap

The gap between the electrodes in the sparkplug determines the ease of spark formation during combustion. Due to thermal fatigue, the gap between electrodes progressively increases with the mileage you accumulate. This may result in the spark not forming from time to time. Thus, the sparkplugs are sometimes switched out about midlife during service checks. If your car becomes a senior citizen in terms of its odometer and it has been a long time since you last changed the spark plug, try replacing the sparkplugs. It might restore the power to a certain extent.

Ignition Coil

The Ignition coil of the car is responsible for generating the level of voltage that is required for the spark. While it is not too common, sometimes, a problem with the ignition coils results in the sparkplug not being able to generate enough for a spark to burn the whole mixture. This then leads to a loss of power. Fortunately, these ignition coils are sitting right at the top of the engine just waiting to be exchanged if required.

Crank sensors

The crank position sensor is responsible for telling the ECU the speed at which the engine is running. Accordingly, the ECU may make decisions related to the spark and injection timing. Accordingly, it also opens the throttle valve. Thus, if the crank position sensor is malfunctioning, incorrect data might change these timings. You have seen the result of this in the previous sections. This can be resolved easily with a change in the sensor as it is relatively inexpensive.

Clutch problems

As you may know, the clutch is responsible for transmitting the engine’s power to the transmission and consequently to the vehicle’s wheels. Over time, this clutch starts to wear out as it is based primarily on the principle of friction. Lower friction means there is some slip between the engine and transmission side, leading to a drop in power. Thus, if your car is rather old, this may be the source of the problem. Unfortunately, this means that you will have to take it to the dealership to get the clutch changed or do it yourself.

Final Thoughts

As you can see, the loss of power in a 350z can be related to a million different causes. Thus, it is important to keep your car healthy and keep an eye out for the check engine light. Identifying any issues early will help avoid potentially bigger issues further down the line.

Finding out the error code from the OBD will help you narrow down the solution. Some of them, fortunately, have easy DIY fixes that can be found in the owner’s manual. As always, we would recommend that you take the car to the dealership for a quick resolution of the problem. But, if you believe in your skills, then stay safe while trying these fixes. Otherwise, we hope to see you enjoying your ride again when you put the pedal to the metal!