One main reason why the automatic transmission in your car may not be shifting smoothly is the ECM is going bad. It is best to get this checked out by an experienced auto mechanic technician who understands the electrical system. Other indicators include bad connections within, or worn out sensors and faulty solenoids.
A vehicle that refuses to shift or into gear smoothly indicates there is a problem with your transmission. In most cases, the culprit is your transmission or clutch. A vehicle's transmission system is very complicated. It has several moving parts, ignoring such an issue could quickly spiral into expensive repairs.
As we mentioned above, dirty or contaminated transmission fluid can cause your car, truck, or SUV not to shift into gear. While most automatic transmissions are sealed systems, the filters or gasket inside will eventually corrode, and cause debris to clog the hydraulic lines.
Automatic transmissions that shift hard, jerk or shake during a shift change may mean your transmission fluid needs changed or fluid level is low. In manual transmission vehicles, abnormal gear shifts could indicate damaged gear synchros, worn clutches or other, more severe issues.
The most likely reason that a car jerks when accelerating from stop is a problem with the clutch. It could be due to worn-out friction material or a pressure plate defect (or combination of both). It could also be caused by an oil leak contaminating the clutch plate.
A car that hesitates to go can be due to a problem with the fuel system, ignition system, or spark plugs. The fuel pump, fuel injector, and spark plugs are common causes of a car hesitating to go.
This hesitation while accelerating can be the result of a number of issues, including something like a clogged fuel filter or even a broken fuel pump. Sometimes, something could also be wrong with the transmission.
An engine that is hesitating to accelerate is most likely dealing with a fuel/air mixture that is too lean. Engine's that are running inefficiently will begin to show signs like hesitation which will only become worse over time.
Common causes of why a car feels sluggish when accelerating include dirty mass air flow sensor (MAF), faulty spark plugs, defective throttle position sensor, clogged catalytic converter, faulty oxygen sensor, clogged air filter, and fuel system malfunctioning.
Car Talk researchers have found that the cost to replace a clutch can range from $750 to $2500, depending on the make and model of the car you drive. How long does it take a mechanic to replace a clutch?
Park the vehicle, set the parking brake, then step on the clutch pedal, and put the transmission into first gear. Listen and feel for any grinding, or other noises when putting the shifter into gear, as that could indicate a potential problem with that particular gears' synchronizer.
If your transmission feels like it is not shifting on time, as if the engine is revving too high and shifts are coming late, you could be having transmission problems.
Don't pass off abrupt changes in your driving soundtrack with a cursory, "well, that's new." Clunking, humming or whining sounds are signs of automatic transmission problems. Faulty manual transmissions will also give off loud machinelike sounds that seem to come out of nowhere.
Dirty Air Filters
The air filter functions to prevent dirt and debris in the air from entering the engine. If it's dirty, it could restrict airflow to the engine, thus reducing the amount of oxygen that the engine gets. This causes an uneven oxygen-to-fuel ratio in the engine which leads to misfiring and car jerking.
A. Misfire During Acceleration
Misfires can happen when a vehicle is under load while accelerating. The most common cause of rough acceleration due to misfires is worn-out spark plugs, a cracked distributor cap, a bad spark plug wire, or a failing throttle position sensor (TPS.)
The Quick Fix:
Clean air filters and fuel injectors will reduce the strain on your car. An engaged emergency brake causes the brake to drag slowing down your car. Disengage the brake to solve this issue. Sometimes acceleration problems are just because of low fuel or poor quality of fuel.
Neglecting oil changes can have serious consequences for your car's performance. Over time, engine oil breaks down and becomes less effective, increasing friction and heat, which strains your engine. This can lead to reduced acceleration, diminished engine power, and other performance issues.