[maly555]

Hi to everyone. I need some help with Skoda CHYB motor.

The car came with faults of misfiring at 1 and 3 cyl.
The engine works well. When make fast accelerate there is no fault and misfiring, but when revs are higher than 3500 it starts to misfire. Then I tried to keep revs between 3500 and 4000 (max revs at neutral) when the car is standing still and I get same situation. At this engine speed 1 and 3 cyl are catching misfires and then it turns off cylinder. (I think only first one).
It has new coils, new spark plugs,new cylinder head, even ecu looks like someone change. I tried to swap them out. Then I swapped injectors from 1 to 2. And nothing happened. Still the same problem.
This car has lpg landi renzo but I disconnet it complete and nothing change.
Fuel trims around 2%
Maybe someone had this situation and solved it?

[pupu144]

I remember seeing TPIs about VAG 3-cyl engine misfires - most of the times it required reflashing ECU. It was some time ago, in 2008-2009, and for older BME engines. I sure hope they have fixed most design flaws since then..
But it doesn't hurt to check if ECU has the latest software.

Also, by your description, it sounds like your problems may be with fueling - dirty/malfunctioning injectors, underperforming fuel pump, clogged filter (if it has one), etc.

[maly555]

In 2020 was fitted brand new ecu, I dont know why... but flash is from 2020
On lpg was the same problem so i dont thing is a fueling, anyway fuel pressure is ok and i swaped injector between 1 and 2 and nothing change
I don't think I'm the first to struggle with this

[pupu144]

Last resort - check crankshaft and camshaft sensors (also check wiring to these sensors - continuity, resistance).
If you are sure that everything is good with electrical part - then it's a mechanical fault.

[maly555]

Yesterday I fit a new cam and crank sensor and nothing... without crankshaft sensor misfire is gone, but I think this is normal