Hello! I'm having a strage problem with om611.962 , c200cdi, a short story of the car is : stage 1 ecu, new rebuilded turbo from gt18 to gt20 , de-cat, egr-off.The problem is like that .. 1st and 2nd gear accelerate normal then if i push it and shift to 3rd (rev drops at about 3200-3400rpm) the car stop accelerating and a lot of smoke release(lack of air). If i let the gas then push it back on sometimes gain full power and go ..sometimes no .also i see that if i'm below 2000rpm and accelerate gently in 4th 5th etc the car slowly gain boost then at about 2200rpm the tubo cuts (sound of air releaseing) .The fault codes stored are p1470 (boost pressure regulator) and p0100 (maf hot film) .What I've done so far: live data from star : 1 and 2th gear make 2.1 bar of boost (1.1 nominal) then on 3rd it drop to 1.6 (0.6) .I've change maf with a bran new oe one, changed filters , change boost pressure transducer( oem,new) , checked all air hoses, clean them , no leaks. check connection maf to ecu, check ecu fuses,intake motor works fine .I think i'm going mad.i have also two questions: the headlights vacuum share the same hoses as turbo and egr? What about rear head rests? the car don't limit at 3000rpm ..i can rev it till the end of range. This week i'm going to put back the original software to see what happens but i m pretty sure is not the software.Any ideas or something to also check? Thanks and a great day!

 

It sounds like the intake port shutoff actuator is binding and keeping the intake port flaps closed, choking the motor off. Can you try to monitor the flaps to see if this is happening? Perhaps you can disconnect the flap control rod from the control motor and lock them open as a test. Also, you can connect a vacuum gauge with a tee fitting to the turbo wastegate vacuum transducer to monitor the vacuum supply to the wastegate during road test. My last thought is that somehow the fresh air inlet duct to the air filter is collapsing under load and restricting air to the filter, you can disconnect it as a test to find out.
Good luck

 

A little update of the car : i was at the tuning company that reflash the ecu and put back the original settings on for testing ... car was ok ,second day we put back the stage 1 ecu software and was still ok ... no more smoke car pulls so nicely, I was on a road trip at about 1700 km and no problem at all and yesterday disaster happened .. out of nowhare car is back with old problems .. turbo cuts at about 2200rpm as error codes is a new code p1626 and still p0100 and p1470 . I pretty sure is a cable or maybe a fuse but i don t know where to look. Any advice would be very appreciated . Thanks! And a little info : car stock made 12.xx to 60mph and when was ok i was 7.9- 8.2 to 60mph with bad tires

 

Update number 3 i think. Today i logged the car again and for my surprise the p0100 is gone after i cleaned up ecu connections and renew fuses. But still the infamous p1470 is there i deleted and it is not stored ..go out with the car pull ok till 2000-2200 then sudden cuts out the turbo.Can someone guide me with an electrical scheme or what impedance voltage should vaccum transducer connector should have ? Thanks!