BWJ Engine - Misfiring on idle and smell of petrol in oil

[Astinz]

Hello guys!
I'm proud owner Seat Leon Cupra 1P with tuned BWJ under hood. After rebuilt of engine (new pistons, forged rods, new rods bearing, renewed head etc.) engine started to misfire on cyl. 3 (about 14 missfires per minute) and cyl. 4 (about 2 misfires per minute). It's only misfiring on idle, also turning on AC is making amount of misfires lower (about 5 misfires per minute on cylinder 3, and no misfires on cylinder 4). There's no single misfire when there's load on the engine. We decided to change coils and spark plugs, but nothing changed. Then I bought brand new injector and replaced it on cylinder 3 to check if there will be no more misfires, unfortunately they're still there. We have also checked the compression, there's 180 psi on every cylinder. After 3k kilometers I realized that I can smell petrol in the oil, I think it's somehow connected with those misfires. There's no carbon buildup - it was cleaned during rebuild. I'm also changing cam follower every 10kkm and there's brand new VIS motorsport internals in HPFP.

There's no single error code in ECU, but misfires are clearly visible on VCDS counter.

Thanks in advance for your support!

 

[Astinz]

Hello guys!
I'm proud owner Seat Leon Cupra 1P with tuned BWJ under hood. After rebuilt of engine (new pistons, forged rods, new rods bearing, renewed head etc.) engine started to misfire on cyl. 3 (about 14 missfires per minute) and cyl. 4 (about 2 misfires per minute). It's only misfiring on idle, also turning on AC is making amount of misfires lower (about 5 misfires per minute on cylinder 3, and no misfires on cylinder 4). There's no single misfire when there's load on the engine. We decided to change coils and spark plugs, but nothing changed. Then I bought brand new injector and replaced it on cylinder 3 to check if there will be no more misfires, unfortunately they're still there. We have also checked the compression, there's 180 psi on every cylinder. After 3k kilometers I realized that I can smell petrol in the oil, I think it's somehow connected with those misfires. There's no carbon buildup - it was cleaned during rebuild. I'm also changing cam follower every 10kkm and there's brand new VIS motorsport internals in HPFP.

There's no single error code in ECU, but misfires are clearly visible on VCDS counter.

Thanks in advance for your support!

Smell of fuel in oil solved. Still misfiring on idle.

 

[R3k1355]

Did you gap the spark plugs when you put them in?

 

[mty12345]

Have you checked the wiring to those coils/injectors?

 

[Astinz]

Wiring is fine, sparkplugs gapped to 7mm. I've also changed the PCV, but still same behaviour. I'm also considering to change N80 valve.