In this article, you will learn about the causes of jerks while driving. The main reasons for jerking while driving on the Nexia are faulty explosives (high voltage wires), spark plugs or a throttle position sensor. Also, the fuel and oil filters may be dirty. Next, we will analyze each of the options in detail.

Why jerks can occur, it is necessary to first figure out what a jerk is. A jerk in cars, often in Nexia, is a short-term spontaneous change in the engine speed, regardless of the position of the gas pedal. In ordinary life, a series of jerks most often takes place. The extreme case of a jerk - a dip is a noticeable delay in the response of the engine to pressing the accelerator pedal. Conventionally, three types of jerks can be distinguished:
–at the moment of the start of movement;
- during overclocking;
- with steady motion, i.e. with the gas pedal constantly pressed.

To determine the causes of jerks when driving a car with an injection engine, you can perform computer diagnostics, so I recommend contacting a service that specializes in repairing fuel injection systems. However, as practice shows, in most cases jerking is caused by insufficient fuel pressure in the fuel rail or a malfunction of the throttle position sensor. If you have some skills, you can determine the cause of the jerks yourself.
JACK AT THE MOMENT OF THE BEGINNING OF MOVEMENT ON NEXIA... Usually, you just started to move and trouble happens - failure or failure after failure. The most unpleasant sensations are associated precisely with the delay in the response of the engine to pressing the gas pedal. Sometimes even the engine even stalls. A jerk occurs at the moment the throttle valve starts to open when the gas pedal is pressed, when, according to the signal from the throttle position sensor, the ECU determines the moment of transition from idle to load mode and must increase the amount of fuel supplied through the injectors. With insufficient pressure in the fuel rail, even with an increase in the duration of the injection, there is not enough fuel for a smooth start-off.
JUMPS WHEN ACCELERATED ON NEXIA... The cause of jerks during acceleration can be, as in the previous case, insufficient fuel pressure in the fuel rail. The electronic engine control unit, having received a signal from the throttle position sensor, about the intensive opening of the throttle at a large angle, seeks to maximize the fuel supply, but due to the reduced fuel pressure, it is not able to do this. In addition, a specific reason for jerking when accelerating a Daewoo Nexia car may be a failure of the absolute pressure sensor (vacuum in the intake pipe) or clogging (pinching) of its hose.
JUMPING WHEN MOVING... Such jerks are most often caused by a malfunction of the ignition system. Diagnostics and repairs are required. If you are on the road, you can try the following yourself:
- carefully examine the engine compartment. Switch off the ignition and check the tightness and seating of all wires and connectors at the distributor sensor and ignition coil on a car with a G15MF engine, connectors on the ignition module and high-voltage wires on cars with other engines. Let go
engine and listen to its work.

- crackle during high voltage breakdown "to ground" is weak, but distinct. In complete darkness, a spark is clearly visible during breakdown;

- replace spark plugs regardless of their condition and mileage. Pay attention to the condition of the spark plugs: if abnormalities are found, it may be necessary to repair the engine or its systems. Failure of the throttle position sensor can be a specific cause of jerks during steady motion of a car with an injection engine.

Additional symptoms confirming a malfunction of this sensor are as follows:
- uneven engine idling;
- decrease in maximum engine power.
The sensor is non-separable and therefore not repairable. If the sensor is found to be faulty, it is replaced as an assembly.

3.5. The car is moving in jerks

With regard to a car, a jerk is a short-term spontaneous change in the engine crankshaft speed, regardless of the position of the gas pedal. In daily use, there are usually a series of jerks. The extreme case of a jerk is a failure, a noticeable delay in the response of the engine to pressing the accelerator pedal.

Conventionally, three types of jerks can be distinguished:

- at the moment of the beginning of the movement;

- during overclocking;

- with steady motion, i.e. with a constant position of the accelerator pedal.

To determine the causes of jerks when driving a car with an injection engine, special diagnostic equipment is required, therefore, in this case, we recommend contacting a car service that specializes in repairing fuel injection systems. However, as practice shows, in most cases jerking is caused by insufficient fuel pressure in the engine fuel line ("rail") or a malfunction of the throttle position sensor.

If you have some skills, you can identify the cause of the jerks yourself.

Jerk at the start of movement

At the moment of the beginning of the movement, the limiting case of a jerk — a failure — often occurs. The most unpleasant sensations are associated precisely with the delay in the response of the engine to pressing the gas pedal. Sometimes the engine even stalls. A jerk occurs at the moment the throttle valve starts to open, when, according to the signal from the throttle position sensor, the ECU determines the moment of transition from idle to load mode and must increase the amount of fuel supplied through the injectors. With insufficient pressure in the fuel line, even with an increase in the duration of the injection, there is not enough fuel for a smooth start-off.

The reasons for the decrease in pressure can be:

Jerks during acceleration

The cause of jerks during acceleration can be, just as in the previous case (see "Jerk at the moment of starting movement"), insufficient fuel pressure in the fuel line. The ECU, having received a signal from the throttle position sensor about the intensive opening of the throttle to a large angle, seeks to maximize the fuel supply, but due to the reduced fuel pressure, it is not able to do this. The reasons for this phenomenon and the method of checking, see "Jerk at the moment of the start of movement".

Jerks with steady motion

Such jerks are most often caused by a malfunction of the ignition system. Diagnostics and repairs are required (see section 9 "Electrical equipment"). On the way, you can try to do it yourself:

- carefully examine the engine compartment. Switch off the ignition and check the tightness and seating of all wires and connectors at the ignition module and high-voltage wires. Start the engine and listen to its work - the crackle during high voltage breakdown "to ground" is weak, but distinct. In complete darkness, a spark is clearly visible during breakdown;

Daewoo Nexia: Does not pull when picking up speed

10.09.2011

Daewoo Nexia: "Doesn't pull when picking up speed"

Car on the recommendation of friends. Not profile. This case was interestingthe fact that the client has already traveled "a certain number of car services", spent "a certainthe amount of money ”, but the result was zero. Then he decided to renovate himself (the Internet is big ...).

I changed the spark plugs - it didn't help. I cleaned the nozzles - nothing has changed.
He had to go to the car service again to bow. Found one. They agreed to undertake repairs there.

But they set the following condition:
- Find the same car as yours, we will put it next to you and take pictures one by onefrom there and put on your car… the way is very good! One hundred percent guarantee!

For some reason, the client decided not to contact this car service. Found another. There he immediately stated:

I connected a vacuum gauge. It showed low intake manifold vacuum.What does this mean? That "something is wrong with the gas distribution system in the engine."Here either the timing belt jumped, or there are questions to the gear,it could be trite "smashed".

I want to focus on one parameter: the ignition advance is very late, that is, the correct "minus" value went "plus" and on the oscillogram shown it appears as "25 degrees after top dead center", although we know that the "correct" ignition should be BEFORE the dead center under the given operating conditions during the acquisition of the oscillogram.

Well. In principle, everything is clear, we have to do it ... turned around, looked ... unfortunately, all our locksmith posts were occupied. Looked at the client:

Do you know a locksmith? Who could do what I tell you?
- Well, basically ... there is ... I will find!
- Then listen to what needs to be done ...

In a few minutes he told the client in detail what and how to do. And finally asked:
- just let them not throw anything away, bring it to me, okay?

... the client arrived ... no - the client burst into our box literally the next day:

- Thanks! No, you have no idea how you helped me! I could not get the right solution to my problem anywhere and from anyone!

And the problem was this, see photo:

If you look "offhand and from the side", is everything okay?

Let's take a closer look:

Yes, this is the so-called "banal veneer groove". Broken.

Outwardly, there is no way to determine that the veneer groove is broken.

Moreover, it is structurally made at the same time with all the detail. So to speak, a "complete detail". And if you look at the gear "simply and from the outside", it is difficult to determine the malfunction. And you can watch for a long time ...
In that car service, they were very surprised when they followed all our recommendations and, indeed, the gear was broken! They were very surprised ...

Just do not think that you have praised yourself now, they say, look how smart. No, there is nothing "smart" or brilliant. It's just “work like that” when you have to keep a lot of information in your head and use it in time.

Kudryavtsev M.E.
© Legion-Avtodata

Kudryavtsev Mikhail Evgenievich
Moscow city
Car service "VTS"
Suzdalskaya st., 9
You can call during business hours:
7-916-626-71-98