Hello everyone

Does volvo 850 ( B5252FS from 1994 ) has an auxilary mode which runs on when the ECU is unable to run on factory settings after a specif time. I have tested my volvo 850 using the onboard diagnostic and it has no faults, but the engine when started has some problems, here its how it looks,

=> when i start it and start to drive after some time in fact can as low as few seconds, the engine stalls, seems like working not on all sparks and builds enormous crankase pressure, which shoots the oil through the oil feeler, and here unfortunatelly there is not any auxilary mode, the problem just stays on

=> if you allow the car after start( and dont press the accelaration !!! ) the engine tries to idle ( ranging from 500 to 1200 few times ) and in about 3 to 4 minutes it goes i guess into an auxilary mode, now You can drive the car for 1000 miles without any problem and all seems to be perfect, unfortunatelly when turn off the igniotion you have to go once again and wait 3 - 4 minutes

Maybe somebody had something like that, any clue would be a great help

best regards