Bought an M3 with a tune - Misfire

[S2000_Europe]

Originally Posted by TopJimmy

Glad it's fixed.

Strange how the problem occurred across both banks (cyls 3,4,6) with just one sensor failure.

hi Jimmy, it was 3,4,5


now is time to enjoy my DTM machine ,

[1000hp]

Originally Posted by S2000_Europe

update 2

The second shop was right, installed M performance coil cables and now the M3 runs perfect.

How did they diagnose this?

[S2000_Europe]

Originally Posted by 1000hp

How did they diagnose this?

From what I learnt, coil should be changed at 50.000 miles.

The previous shop swapped the coil and changed the sparks and the car was misfiring.

The second shop told me that I have two problems; misfires and running lean.

Running lean did not make sense because the other sensors said the opposite.

The second shop wanted to assure that the coils where fine, sometimes when you pull them you can damage them. Makes sense to change coil once you open everything.

The Misfires gone after the change of coils.

The lean diagnostic gone after changing the the primary O2 sensor.


The first shop was servicing this Volkswagen... for sure they are good with VAG but not with BMW

[1000hp]

Originally Posted by S2000_Europe

The Misfires gone after the change of coils.

You mean the coil wires?

I ask because I have an intermittent miss on #6 at cold start. I have already replaced the coil and I'm getting ready to replace the injector, but I'll take a look at the coil wiring when I get in there.
Resistance and voltage drop tests should reveal an issue in the wiring, but you never know. So I'm curious how the second shop pinpointed the coil wires as the cause.

[S2000_Europe]

Originally Posted by 1000hp

You mean the coil wires?

I ask because I have an intermittent miss on #6 at cold start. I have already replaced the coil and I'm getting ready to replace the injector, but I'll take a look at the coil wiring when I get in there.
Resistance and voltage drop tests should reveal an issue in the wiring, but you never know. So I'm curious how the second shop pinpointed the coil wires as the cause.

it was a combination of the wires and a bad o2 sensor, MAF sensor screws...

While checking what the first shop did, They noticed that the wires were in bad shape.

Maybe the center off all of this was the faulty O2 sensor.

[1000hp]

Originally Posted by S2000_Europe

it was a combination of the wires and a bad o2 sensor, MAF sensor screws...

While checking what the first shop did, They noticed that the wires were in bad shape.

Maybe the center off all of this was the faulty O2 sensor.

Interesting. Thanks.

[S2000_Europe]

after 300 miles everything is perfect.

Yesterday Alex from alpine motorsports coded the dct and suspension to gts and cs standards respectively and he was able to tune the car, even though the shop number 1 updated the DME software to 2020 using ISTA

I went for a conservative tune. Nothing crazy and deleted burbles, I do not like them at all.


thanks all for your help, now I am enjoy the car a lot