P0302 cylinder 2 misfire detected

[Mantas_248]

Hi all thought I’d give this forum a try to see if anyone can help me out with a problem I’ve been having for over 6 months now as no one is being able to find the problem. So my car which is a 2014 Mercedes a class a180 1.6L with around 88000 miles when the problem started, it had started to misfire in cylinder 2. I’ve taken the car to various garages with no answers at all. Lots been done to the car to try and figure out the problem but nothing, so far ignition coils have been swapped around with other cylinders to see if it follows nothing, comes back to cylinder 2. Spark plug changed for cylinder 2 still nothing changed. The fuel injector changed for cylinder 2 still nothing changed. An update to stop compression misfires was done to the ecu which fixed nothing. Multiple cold and hot engine compression test down which came back fine with no problem. The entire engine wiring harness changed which didn’t fix the problem. Just to Throw it in here when I got the injector and update changed the garage I went too wasn’t the The best looking back as at the time I didn’t really know who to go, they even told be they was having trouble coding the injector. symptoms the car is having are rough idle and that’s it. When I start the car it’s if someone’s got there foot on the gas pedal and it sits at around 1200 rpm till it settles down around 700rpm and the shaking starts. You can feel a consistent misfire happen all the time when in idle and under no load. And if the misfire is really bad the eco will completely shut off and disappear of the screen. The car when its driven drives perfectly with no problem at all pulls fine. I’ve had the engine light come on dozen of times for this problem which sometimes goes out on his own and disappears for a week or two. I have some of a idea where to head next, at first I thought the timing chain is going but found out that they are non serviceable thing so that’s out the window I guess. Then I thought it’s my ecu which I still think could be. My knowledge isn’t the best and all research down over the internet and I sort off put two and two together but still unsure. I had an alternator failure on the car which I didn’t get changed straight away so could that off messed the ecu up and changed some of the readings it has stored because the voltages wasn’t what it was supposed to be at. As of right now I’m thinking it’s an ignition timing issue or an ecu needing to be reprogrammed but want to be certain as to not spend unnecessary money like I did before. Sorry for the long explanation didn’t want to miss anything out. Thank you in advance. also there was a knocking noise coming from the engine but seem to off disappeared at the moment.

 

[Botus]

can u get a second hand ecu cheap and try that.... these are no longer an item that does 25 years no issues

if it seems to run right and mechanically checks out, doesn't seem much else and you changed the rest.....

can u swap the injector between cyls for good measure / peace of mind as you wait for the replacement ecu ? (I expect will need a guru to fit due to fun with immobiliser)