VW Polo 1.2 code reads p0303 cylinder 3 misfire ?

[volorucinski]

I bet on your experience, Meat-Head. Let's hear the man, after he does the whole check on the car...

P.S.: two days ago came a polo 1.2 (p0302) and a week agothis fabia 1.4 with the same errors. P0303. They came from different garrages after changing coils, injectors, changing map, pipes, vacuum leak tests ect. They came to change the ecu... And after codi g the new ecus, the problem remained. That I was telling them before doing that. I asked them about the compression test and both said I am joking, because the other garrages thougth it might be injector or coil problem. So... It confirms that after changing the ecuus, the problem stays the same. I don't do mechanics, so... They went as they came... Money spent for nothing, instead of doing a compression test.

[swisstuner]

I bet on your experience, Meat-Head. Let's hear the man, after he does the whole check on the car...

P.S.: two days ago came a polo 1.2 (p0302) and a week agothis fabia 1.4 with the same errors. P0303. They came from different garrages after changing coils, injectors, changing map, pipes, vacuum leak tests ect. They came to change the ecu... And after codi g the new ecus, the problem remained. That I was telling them before doing that. I asked them about the compression test and both said I am joking, because the other garrages thougth it might be injector or coil problem. So... It confirms that after changing the ecuus, the problem stays the same. I don't do mechanics, so... They went as they came... Money spent for nothing, instead of doing a compression test.

100% agree with this poster. I might be new here but dont let post counts fool you. Theres a lot of swaptronics monkeys out there now who with a bit of money buy a tool, run a scan and send themselves and customers on a wild goose chase. Mechanicking 101 - first confirm there is NOT A PHYSICAL problem, then focus on the electronics.

[SDIracer]

Compresion on misfire cylinder no need to be drasticly low, 10-10,5 bar is enough.

In most cases inlet valve is problem.

[volorucinski]

Compresion on misfire cylinder no need to be drasticly low, 10-10,5 bar is enough.

In most cases inlet valve is problem.

I bet you are a good mechanic... I am not allowed to say that 10bar is a good compression, even if engines are different. But I am saying it: 12bars is a minimal treshold for an engine to work ok.. 17bars are for stock new. . At 10,you have some problems on that engines. Btw... We are talking obout compreasion test ade on cold, or hot engine? Wtf does anybody know about engines? I am not a mechanic... So i think i will let anybody brake his head on doing it.

When you check compression, it is measured on outlet valves compression, only if inlet valves are bended you will say that compression will be sent back to the intake...
. Ask ayone who knows about engines, and i am not speaking of sh*t garrages on your block corners... Nor the dealers. There are a lot of lacks and countries in need of good mechanics and electricians to do this job. On the other way, dtcs like p0301,
for example, ar referring to a problem on mechanical issue on cylinder no1. This problem can be generated by low compression(mechanical problem), injector not working, or even false air, fuel pump not injecting correct pressure into the regulator, or even sparks, spark plugs, coils or loosen screwed sparks, or even distribution mismatch...
always there will be other dtcs associated with this "mechanical error" that could be generated by electrical problems, false air, phisically mechanical problems or even more. I always said that i am an electronist, not a mechanic. But... I don'tcare if anyone spend money for changing ecuus or coils annd injectors because of a stupid garrage diagnose.[/QUOTE]