Opel Zafira-B Z16XEP Erratic idle

Hi everyone,

Zafira-B Z16XEP, 2005, MT35E. It has erratic idle after you let it sit for 10 seconds. Does not matter if engine is hot or cold. New timing belt, ignition coil and sparkplugs. EGR channels and throttle body cleaned, new EGR valve. Nothing has helped so far. Only two things spotted, throttle position PWM servo signal goes up and down +/- 30% and when you press pedal firmly, the RPMs cycle up and down. ECU always reports misfire DTCs on all cylinders after a long drive.
Video of engine running and TB position PWM signal:
https://www.youtube.com/watch?v=cO43YEwLEww

Has anyone experienced such problem on Z16XEP ? I'm betting on damaged throttle body, but new one is pretty pricey. I still have not found any TB adaptations, don't know if it is even possible on Z16XEP.

Damaged throttle body, many times deal with that. Replace it and without adaptation it need to be good

coolant temperature 113!? ,valve cover -membrane

crank shaft reluctor ring in the box or have you tried an actual cam shaft cover as they have a breather in there.
if you take the oil filler cap off when its running it will try pulling it back on id be trying a rocker cover on it first for sure

Valve cover has been also replaced, but not recently. I'll try another throttle body and report back later. Thank you all for responding.

Well, replacement of throttle body did not help and membrane in the valve cover is alright, but disconnecting lambda sensor made the engine run flawlessly. Replacement of the lambda sensor did not help at all, only slightly.

Can you show us the fuel data trims ?
I have seen bad map sensors, brake servo unit with leak, and many others with this engine.

Yes, long term fuel trim is always at 0 %, short trim sometimes goes slowly up to 5 %, but mostly is at 0 % even while idling for a while. Today after cleaning injectors it went up to -15%, also was smoking but after driving it went back to 0-5 % as before. MAP sensor stays stable at around 40-45 kPa at warm idle. From now, EGR is blanked with a plate, drilled small pin holes into plate, injectors are cleaned, repaired swirl flaps and new gaskets on intake manifolds. It runs absolutely same as before, with no change.

Yes, long term fuel trim is always at 0 %, short trim sometimes goes slowly up to 5 %, but mostly is at 0 % even while idling for a while. Today after cleaning injectors it went up to -15%, also was smoking but after driving it went back to 0-5 % as before. MAP sensor stays stable at around 40-45 kPa at warm idle. From now, EGR is blanked with a plate, drilled small pin holes into plate, injectors are cleaned, repaired swirl flaps and new gaskets on intake manifolds. It runs absolutely same as before, with no change.

DID YOU CHECK THE METALLIC HOSE WHICH GOING TO EGR VALVE FROM THE INTAKE MANIFOLD? GIVE IT A SPRAY OF BRAKE CLEANER IN THAT SPOT AND SEE WHAT IS IT DOING.
FUEL PUMP PRESSURE? PRESSURE REGULATOR CHECK.
BE CAREFUL THE MEMBRANE OF THE COVER BECAUSE I HAVE SEEN MANY OF THEM STUCK FOR A WHILE AND AFTER ALL GOOD.
TRY A MAP SENSOR IF YOU HAVE ONE.
CHECK YOU CATALYST FOR BLOCKING.
BRAKE SERVO UNIT FOR AIR.SHUT DOWN THE ENGINE ,AFTER 2 MINUTES PRESS THE PEDAL AND SEE IF IS SOFT OR WHEN ENGINE IS ON CHECK YOUR LAMDA SENSOR AND SHORT TERM AND PRESS VERY SLOWLY YOUR BRAKE PEDAL AND SEE THE TERM IF IT IS CHANGING 
OR TAKE OUT THE BRAKE SERVO HOSE AND PLUG IT TO SEE ANY DIFFERENCE.
OIL CONSUMPTION AND VALVE ADJUSTMENT CHECKING?