I have an '02 Cavalier Z24 with a 2.4l engine. This car has a lot of (275,000) highway miles and has been an unbelieveably reliabe car. Nothing has failed and I have done/had normal mainteance done at regualr intervals. This car still has the original clutch and doesn’t slip. Anyways, when driving and the engine is put under load at low RPM’s, The car nearly violently chugs. Ex. 20mph, third gear half throttle, 1500 RPM’s. You would expect the car to slowly and smoothly accelerate. Instead it chugs and chugs, shaking the car forward and back until you get over about 2300-2500 RPM’s. It’s seems like it’s starving for fuel. It has also not started before. Just turns over and over. A shot or ether downstream in the air intake makes her start right up and then it runs fine. Any suggestions besides retire this car. My next goal for this car is 350,000
I would look at the signal from the crank position sensor or cam sensor. Theses sensors control timing of the fuel injectors. I’m not familiar with this engine so I can’t be more specific.
These sensors are generally inductive. They have a coil, a magnet and generate a pulse when some kind of metal finger that passes by the coil. The signal from the coil increases with engine speed. So if the sensor is marginal it will make trouble first at low RPM’s.
That makes some sense to me. My check engine light has been on for some time now but cannot be diagnosed by a standard code reader. I have tried several commercial shops, Autozone, Advance Auto Parts and no one’s code reader can communicate with the computer to read the code. I’ve not been relishing the thought of taking the car into the dealer because of the high expense I’m probably looking at. I’ve been told be several people that the dealer will have to pull the codes. The Dealer replaced a number of electrical components over about a 7 week period of having my car after a lightening strike. Computer, Ground Control Module, Body Control Module, 3 of the 4 ABS sensors and I think one other control module or sensor. I guess I’m just going to bite the bullet and take the car to the dealer to try to diagnose the codes. The car was doing this once before around 115k miles and I ended up replceing the fuel pump because the pressure wasn’t very consistent. It seemed to fix the problem back then but I’m relucentent to do that again without getting the engine codes read first.
Thanks for your post.