Car jerking during acceleration

[Ungtiong]

I have this problem.......when i drive my car in the morning or after parking for a long time, when i accelerate hard, the car will jerk a few times (4-5 times) at around 5000 rpm...this will ALWAYS happens once in the trip and after that in the same trip, no matter how hard i accelerate, i can never repeat the jerking. When the car is jerking (or engine hesitating) the speedo will jump around.

 

What seems to be the problem that will only happened once per trip.....after that the car drives fine. If i never accelerate hard, the car is also fine.

 

Spark plugs changed, air filter clean, mass airflow sensor cleaned, engine oil changed.....

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Cook123]

if spark plug problem, will be cheap to solve.

[Elmo]

Without knowing your car model and mods I can only guess it is a fueling issue. 5K rpm is almost redline for some cars but since you say it only happens once per trip could mean the first time you whack till 5K rpm, your fuel pump couldn't keep up.

[Torquemonster]

Without knowing your car model and mods I can only guess it is a fueling issue. 5K rpm is almost redline for some cars but since you say it only happens once per trip could mean the first time you whack till 5K rpm, your fuel pump couldn't keep up.

 

 

That is what i am thinking as well. Not enough fuel supply. Could be crappy fuel pump, clogged up fuel filter, water in the fuel line(highly unlikely since it only happens every trip).

[Divpan]

hows the battery doing? Is it time to change? Recently met with some batteries issue and my car jerks when idle at traffic lights, and the car seems to face strong "pull-backs" when I reduce speed, before coming to a stop...

[Fcw75]

Have you changed your fuel filter yet? Something to do with delivery of fuel perhaps?

[Roadhogger]

Do u rev up to 5k rpm every morning? What happens if 2 or 3k rpm?

[Yeobh]

In the morning, ambient temp is not very warm so fuel inside the system don't vaporise so there is no air bubbles in the system. Even the top header ( fuel system pressure ) pressure is low you still can start the car due to cooler temp.

Once you start driving, heat built up and that have strong influence on the fuel system causing the fuel to vaporise resulting in bubbles formation, due to the weak pump pressure the bubbles will continue to remains in the system.

Once you shut down the engine, the fuel starts to absorb more heat -thereby creating more bubbles and that greatly reduce the fuel hydraulic pressure in the system.

The next starting will be a problem and if the engine starts -driving and acceleration will be very rough due to the presence of bubbles in the fuel system.

Consclusion - go for a fuel pressure test and the chance yr fuel pump needs to be replaced.

[Pisces69]

I have this problem.......when i drive my car in the morning or after parking for a long time, when i accelerate hard, the car will jerk a few times (4-5 times) at around 5000 rpm...this will ALWAYS happens once in the trip and after that in the same trip, no matter how hard i accelerate, i can never repeat the jerking. When the car is jerking (or engine hesitating) the speedo will jump around.

 

What seems to be the problem that will only happened once per trip.....after that the car drives fine. If i never accelerate hard, the car is also fine.

 

Spark plugs changed, air filter clean, mass airflow sensor cleaned, engine oil changed.....

 

 

Maybe e auto choke faulty. Mix too lean when cold.

[Rustyz]

what car? seem like throttle hay wire

[Wishxsr]

I have this problem.......when i drive my car in the morning or after parking for a long time, when i accelerate hard, the car will jerk a few times (4-5 times) at around 5000 rpm...this will ALWAYS happens once in the trip and after that in the same trip, no matter how hard i accelerate, i can never repeat the jerking. When the car is jerking (or engine hesitating) the speedo will jump around.

 

What seems to be the problem that will only happened once per trip.....after that the car drives fine. If i never accelerate hard, the car is also fine.

 

Spark plugs changed, air filter clean, mass airflow sensor cleaned, engine oil changed.....

 

 

My cousin have the same problem on his Optra, he get it fix last saturday at katc. Problem solve after changing the ignition coil , ignition cable. Now the ride is very smooth and powerful.Hope it will help u on that.

[Sly]

Hi I have similar problem with my ford focus 1.6L not solve yet, auto shops advised me to change the 02 sensors and the ignition coil .......well how do i get in touch with katc.

 

[Wishxsr]

Hi I have similar problem with my ford focus 1.6L not solve yet, auto shops advised me to change the 02 sensors and the ignition coil .......well how do i get in touch with katc.

 

 

 

U can call the boss Raymond @ 97775200, the workshop located at lor 8 toa payoh, forgotten the unit number.

[Bensonawyong]

You get the jitters from the moving off from stationery part or after u had smoothly moved off?