Q: I have a Nissan Almera and it constantly jerks between 1500 and 2000 revs. Already replaced camshaft sensor and plugs. Please help.

Hi, thanks for writing in. I’d be happy to provide my insight. A symptom such as this can certainly be difficult to figure out. If I were working on your car, I would connect a scanner to it, check and see what data it provides, and if it provides me with the necessary data, I would take your car on an extensive test drive while I watch and record the data. If this is occurring consistently, it will be fairly simple to catch a glitch in one of the sensors. Granted, it takes the knowledge and experience to know what and when to look for it.

The best this will do is isolate the component system that is creating the problem. From there a thorough inspection of the sensor and wiring will ensue. Often this can be quite time consuming. In addition, direct testing with some advance equipment will be required. Which equipment depends on which system is the suspected culprit. This will require a few hours of diagnosis at the least. It really depends on the experience level of the technician.

You have replaced the camshaft sensor, but the crank sensor is what affects the tachometer, (rev counter). So I would begin by monitoring the crank sensor pattern. This is advanced diagnostic work, so you will need someone who has a lot of experience doing these sorts of things.

If you would like help, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this issue for you, and make or suggest any repairs as needed.