What is the reason why the car can't accelerate uphill?

If the engine is basically normal when running at no load, but the acceleration is slow when running at load, and the car can't climb the hill, the accelerator pedal still feels that the power is insufficient and the speed is not high enough to reach the maximum speed. The main reasons for the failure are:

(1) The air filter is blocked.

(2) The throttle valve cannot be fully opened due to improper adjustment.

(3) The fuel pressure is too low.

(4) The injector is blocked or poorly atomized.

(5) Water temperature sensor failure.

(6) Air flowmeter failure.

(7) Improper ignition timing or weak high-voltage spark.

(8) The engine compression pressure is too low.

Extended data:

Automobile failure is the phenomenon that the automobile can't complete its functions, such as engine starting difficulty, automobile failure, automobile oil leakage, lighting system failure and so on.

There is something wrong with a car. Common faults include: sudden change of working conditions, abnormal sound, peculiar smell, abnormal smoke exhaust, abnormal temperature, abnormal appearance, abnormal consumption of fuel and lubricating oil, and leakage. Common faults refer to those that occur frequently and are often encountered in use.

Unable to start or difficult to start.

The phenomenon that the engine can't start may be that the ignition switch is turned on without any signs of starting, the starter is noisy but can't turn, the starter can turn but can't drive the engine, or the starter can drive the engine but can't start. The phenomenon of difficult starting may be slow engine speed or engine rotation.

The sound is uneven when moving. The starting difficulty may occur in freezing weather or extremely hot weather, or at room temperature, or it may be that the cold car is difficult to start for the first time and the hot car will start normally when it is hot.

These phenomena are related to the main injector, cold start injector, temperature control switch, ECU and control circuit working poorly, battery power shortage, igniter or pulse generator damage, fuel system failure or abnormal oil supply. For an automatic car, the failure to start may be due to the incorrect position of the transmission handle.

Poor idle speed operation

Engine jitter may be caused by unstable idle speed, idle speed is higher than the specified upper limit, idle speed is lower than the specified lower limit, or idle speed is not soft. These phenomena are related to the failure or poor work of fuel injector, oxygen sensor, air flow sensor and exhaust gas recirculation valve, and the poor connection between control circuit and vacuum tube.

Abnormal sound

There are tempering, shooting, surge, knocking and mechanical abnormal sound. "Tempering" is a phenomenon that the combustion flame is ejected from the intake pipe in the opposite direction to the intake and makes a sound. The reason of "backfire" may be that the main injector and the cold start injector are blocked and stuck, resulting in too lean mixture, too late or disorderly ignition, unsealed intake valve, leakage of intake manifold, too low oil pressure or high pulsation.

"Beating" is the phenomenon that the incompletely burned mixture burns in the exhaust pipe and makes a sound. The causes of "ignition" may be inaccurate or disordered ignition timing, weak or no fire caused by high voltage coil fault, improper spark plug electrode gap, poor idle valve and so on.

The main injector or cold start injector is not tightly sealed, the oil circuit pressure is too high, the exhaust valve is not tightly sealed or the cylinder pressure is too low, and the temperature sensor or cold start temperature control switch is grounded, which makes the control system fail, leading to oil injection from cold start injector.

"Surge" is an abnormal sound caused by the periodic fluctuation of engine speed. The reasons for "surge" may be that the vacuum interface of the intake pipe is blocked, so that the pressure sensor can not sense the vacuum degree of the intake pipe in time, the timing belt is aging, the teeth are jumping, the exhaust gas recirculation (EGR) system fails, and the turbocharger system fails.

"Knock" is the phenomenon that the engine makes a sharp and crisp impact sound when the car accelerates. It may be caused by excessive ignition advance angle or the use of low-grade gasoline (low octane number). Mechanical abnormal sound may be caused by misalignment of engine moving parts or excessive mating clearance caused by wear of parts.

Reference link: Baidu Encyclopedia-Common faults of automobiles