Hi.
I know there are a lot of similar topics on the Internet. However, I want the most accurate diagnosis possible, so that I do not replace parts at random. In similar topics, suspicions fall on: candles, coil, EGR, throttle, timing, clutch, airbags, TPS sensor, lambda probe and so on ... For now, I can't afford all these parts ;)
So I will describe it as precisely as I can:
Engine 1.8 16V X18XE1, Gasoline + LPG.
-When you press the gas pedal harder, the engine jerks. 3-4 jerks appear and it continues to drive normally.
-It appears most often around 1500-2000 revolutions. When I want to "get out" from a relaxed ride to a more dynamic one. But sometimes also with higher ones.
-Appears when I push the gas harder. When I press the gas lightly and gradually, I can ride without any jerks.
-Most often in gears from 3 upwards. Sometimes on 2.
-Often also when I drive longer with an even speed and I suddenly need to push down (e.g. overtaking).
-Most often on a warm engine.
-Most often on warm days. When it is cold outside (as it is today), the jerk will happen 1-2 times for several kilometers. Recently, when it was warm, it jerked every time I pressed the gas harder.
-It happens on both fuels. It is slightly less noticeable on petrol - rather as a strong wave of the engine. The gas is more noticeable - engine interruption.
-The problem is not permanent. A few weeks ago, I was driving for two weeks without jerks.
General engine behavior:
- It goes smoothly, quietly.
- He does not stop at idle speed. Slight waves, mainly in the cold. When I look at the clue, something curls a little.
-Idle speed approx. 700-750.
-Don't stop when moving off
-When driving without gas (in the sense: I am driving on two at the lowest revs and do not touch any pedal) the car runs evenly, does not stop
-A bit of silt in the lower parts of turns. An attempt to dynamically accelerate from 1000 revolutions to 2000 revolutions in second gear (and higher) is silting. It only pulls nicely after 2000 turns up.
What I checked, I replaced:
- "Check" does not light up.
-Bugs checked. There are no errors. An old error related to working with LPG remains in my memory. P0130 (O2 sensor circuit voltage too high) but reported as "not present".
-The difference in driving between LPG and PB is negligible. LPG on new components, recently regulated. Apart from these jerks, the engine works very nicely.
-Candles replaced. Denso TT. Matched to the engine.
- Air filter replaced
- Throttle cleared
-EGR cleaned
- Adjustable backlash on the gas line
-When I step on a standstill, relaxed, the revolutions increase correctly, dynamically, without jerks. They also descend well.
- I also looked at the flow meter. Zero dirt. Looks like new.
I am asking for advice and a lead. What should you pay attention to in the first place?
I think about ignition all the time intuitively. It bothers me that the jerking changes under different conditions. A jerking "warm" would rather indicate the coil. I bought candles for PLN 9 each. I had no objection to the Denso before, but maybe they are fakes?
One more thought: Even though the engine works well on gas, maybe the maps are broken? The gas was regulated in March when it was cool. Since then, I only use gasoline until I switch to gas. Maybe the ECU does not know the feeling of driving on gas on hot days?
And the wrong dosage? Do you think driving under these conditions only on petrol can improve it?
I know there are a lot of similar topics on the Internet. However, I want the most accurate diagnosis possible, so that I do not replace parts at random. In similar topics, suspicions fall on: candles, coil, EGR, throttle, timing, clutch, airbags, TPS sensor, lambda probe and so on ... For now, I can't afford all these parts ;)
So I will describe it as precisely as I can:
Engine 1.8 16V X18XE1, Gasoline + LPG.
-When you press the gas pedal harder, the engine jerks. 3-4 jerks appear and it continues to drive normally.
-It appears most often around 1500-2000 revolutions. When I want to "get out" from a relaxed ride to a more dynamic one. But sometimes also with higher ones.
-Appears when I push the gas harder. When I press the gas lightly and gradually, I can ride without any jerks.
-Most often in gears from 3 upwards. Sometimes on 2.
-Often also when I drive longer with an even speed and I suddenly need to push down (e.g. overtaking).
-Most often on a warm engine.
-Most often on warm days. When it is cold outside (as it is today), the jerk will happen 1-2 times for several kilometers. Recently, when it was warm, it jerked every time I pressed the gas harder.
-It happens on both fuels. It is slightly less noticeable on petrol - rather as a strong wave of the engine. The gas is more noticeable - engine interruption.
-The problem is not permanent. A few weeks ago, I was driving for two weeks without jerks.
General engine behavior:
- It goes smoothly, quietly.
- He does not stop at idle speed. Slight waves, mainly in the cold. When I look at the clue, something curls a little.
-Idle speed approx. 700-750.
-Don't stop when moving off
-When driving without gas (in the sense: I am driving on two at the lowest revs and do not touch any pedal) the car runs evenly, does not stop
-A bit of silt in the lower parts of turns. An attempt to dynamically accelerate from 1000 revolutions to 2000 revolutions in second gear (and higher) is silting. It only pulls nicely after 2000 turns up.
What I checked, I replaced:
- "Check" does not light up.
-Bugs checked. There are no errors. An old error related to working with LPG remains in my memory. P0130 (O2 sensor circuit voltage too high) but reported as "not present".
-The difference in driving between LPG and PB is negligible. LPG on new components, recently regulated. Apart from these jerks, the engine works very nicely.
-Candles replaced. Denso TT. Matched to the engine.
- Air filter replaced
- Throttle cleared
-EGR cleaned
- Adjustable backlash on the gas line
-When I step on a standstill, relaxed, the revolutions increase correctly, dynamically, without jerks. They also descend well.
- I also looked at the flow meter. Zero dirt. Looks like new.
I am asking for advice and a lead. What should you pay attention to in the first place?
I think about ignition all the time intuitively. It bothers me that the jerking changes under different conditions. A jerking "warm" would rather indicate the coil. I bought candles for PLN 9 each. I had no objection to the Denso before, but maybe they are fakes?
One more thought: Even though the engine works well on gas, maybe the maps are broken? The gas was regulated in March when it was cool. Since then, I only use gasoline until I switch to gas. Maybe the ECU does not know the feeling of driving on gas on hot days?
And the wrong dosage? Do you think driving under these conditions only on petrol can improve it?
It was that insulation - wadding / fleece from the end silencer. I couldn't go further on the road, because when I broke off the tail, after starting the engine, a new one came out. I was forced to pull the entire tail (about 2 m) out of the exhalation. There was also some soot. By controlling the exhalation, I find that it was already done by the previous owner. Has any patch welding marks.
