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

Why jerks can occur, you first need to understand 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 limiting case of a jerk, dip, is a perceptible delay in the engine's response to pressing the accelerator pedal. Conventionally, three types of jerks can be distinguished:
–at the start of the movement;
- during acceleration;
- in steady motion, i.e. while constantly pressing the gas pedal.

To determine the causes of jerks when driving a car with an injection engine, computer diagnostics can be performed, so I recommend contacting a service that specializes in repairing fuel injection systems. However, as practice shows, in most cases, jerks are caused by insufficient fuel pressure in the fuel rail or a malfunction of the throttle position sensor. With some skills, the cause of jerks can be determined independently.
JERK AT THE TIME OF THE STARTING 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 nozzles. With insufficient pressure in the fuel rail, even with an increase in the duration of injection, there is not enough fuel for a smooth start.
JERKS DURING ACCELERATION 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 damper 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 cause of jerks during acceleration of a Daewoo Nexia car may be a failure of the absolute pressure sensor (vacuum in the intake pipe) or a clogged (pinched) hose.
JERKING WHEN MOVING. Such jerks are most often caused by a malfunction of the ignition system. Diagnosis and repair required. If you are on the road, you can try to do the following yourself:
- carefully inspect the engine compartment. Turn off the ignition and check the reliability of fastening and landing of all wires and connectors at the distribution sensor and the ignition coil on a car with a G15MF engine, connectors of the ignition module and high-voltage wires on cars with other engines. Let me go
engine and listen to it work.

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

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

Additional symptoms confirming a malfunction of this sensor are as follows:
– Uneven work of the engine idling;
– reduction of the maximum power of the engine.
The sensor is non-separable and therefore non-repairable. If a sensor malfunction is detected, it is replaced as an assembly.

Daewoo Nexia: Does not pull when accelerating

10.09.2011

Daewoo Nexia: "Does not pull when picking up speed"

... and not only does not pull when picking up speed. When this car drove into our box,then he stopped by for about five minutes. The client presses on the gas, and the car "dulls", does not pull andcan’t even move a small hillock… but then the client was lucky, he helped acceleration with your foot and ... the car is in boxing.

Car recommended by a friend. Not profile. This case was interesting.by the fact that the client has already traveled around “a certain number of car services”, spent “a certainamount of money", but the result was zero. Then he decided to repair himself (the Internet is big ...).

Changed the spark plugs - didn't help. I cleaned the injectors - nothing changed.
He had to go back to bow to car services. Found one. They agreed to take over the repairs.

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:

This cause of the malfunction is known to us - we are repairing ...
- So what's the reason?
- Catalyst! Right now, we will knock it out for you and ...

The client turned out to be "finicky". Well, he did not like it either there or here. Some kind of "sixth feeling,” he realized that he had to make the only right decision: “Go to the diagnosticsto the "correct" car service. I decided to decide, but I was afraid: “And how much money is they stealing there? ...”.
Looking ahead, I’ll say: “They screwed up a little.” Yes, and they didn’t “stupid” at all. Just spent the "correct"self-diagnosis, and when the client was told the price for the work done, he was very surprised:
- And just something?

Well, let's start to tell and show ...

Plugged in a vacuum gauge. It showed low vacuum in the intake manifold.What does it say? The fact 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 tritely "broken".

A similar situation was described in an article at:
and this motor was similar in operation to the work of that motor on the Mitsubishi Lancer.

Next, we take the Postalovsky oscilloscope. Instead of a spark plug, we screw in the pressure sensor, start the engine, look ... and make sure of the initial diagnosis: the oscillogram shows many deviations from correct operation. It turns out that the "phases are shifted."

I want to focus on one parameter: the ignition timing 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 dead center under these operating conditions at the time of acquisition of the waveform.

Well. In principle, everything is clear, we must do it ... I turned around, looked ... unfortunately, all our locksmith posts were occupied. Looking at the client

Do you know a locksmith? Who could do what I tell you?
- Well, in principle ... there is ... I will find it!
- 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, agreed?

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

- Thank you! No, you have no idea how much you helped me! I couldn't 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", then everything is fine?

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 the whole detail. So to speak, "the whole detail." And if you look at the gear "simple and from the side", 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 turned out to be broken! They were very surprised...

Just do not think that now he praised himself, they say, look how smart No, there is nothing "smart" or brilliant. It's just "such a job" when you need to keep a lot of information in your head and use it in time.

Kudryavtsev M.E.
© Legion-Avtodata

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

3.5. The car is jerking

In relation 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 operation, as a rule, there are a series of jerks. The extreme case of a jerk is a failure, a noticeable delay in the engine's response to pressing the accelerator pedal.

Conventionally, three types of jerks can be distinguished:

- at the moment of the beginning of the movement;

- during acceleration;

- with steady motion, i.e. at 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, jerks are caused by insufficient fuel pressure in the engine fuel line (“ramp”) or a malfunction of the throttle position sensor.

With some skills, the cause of jerks can be identified independently.

Jerk at the moment of the beginning of the movement

At the moment of the beginning of the movement, there is more often an extreme case of a jerk - a failure. The most unpleasant sensations are connected 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 opens, 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 nozzles. With insufficient pressure in the fuel line, even with an increase in the injection duration, there is not enough fuel for a smooth start.

The reasons for the decrease in pressure can be:

Jerks during acceleration

The cause of jerks during acceleration may be, as in the previous case (see "Jerk at the start of 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 damper at 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 verification, see "Jerk at the moment of the start of movement."

Jerks in steady motion

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

- carefully inspect the engine compartment. Turn off the ignition and check the reliability of fastening and landing of all wires and connectors at the ignition module and high-voltage wires. Start the engine and listen to its work - the crackling during the breakdown of high voltage "to ground" is weak, but distinct. In complete darkness, a spark is clearly visible during breakdown;