M50 holding back when its cold

[Kristo]

E30 with m50b25tu

when engine is cold, it jerking and hold back a lot.

if temp is about 90C its good and drives like a dream.

diagnostic dont shw any fault codes.

is it can be lambda? diagnostic shaow that lambda voltage moves
very lazy and only 0,5-0,6 v, but when temp is 90+ it moves 0,1-0,9v.

I tried on another lambda too, from m40, but its same.

how mutch must be the resistance of lambda heating?

or anyone have some better idea?
lambda costs about 100€, its not cheap if it is not that problem

[kevo]

is your lambda sensor a bosch type one? assuming it is you just check for continiuity between the heater pins (3 and 4) if it's open circuit then the heater side is faulty and the o2 sensor is kaputt. the voltage at idle should fluctuate between 0.2 and 0.8v.
if you want to test how well it works or not then when you suspect the lambda is being lazy create an air leak (lean) situation and monitor the voltage change, and then pull the vacuum hose off the fuel pressure regulator to create a over pressure of fuel and a rich situation.
this should give you an indication of it's health
hope this helps
Kev

[e30-EVN]

Sounds lambda to me mate to be fair.

My m50 was the other way round, it run better when cold then flat when warmed up. That was bad lambda.

But my m52 run shite when cold and better warmed up... Knackerd lambda x2!

Now I've put good lambda's in the car is brilliant both cold and warmed up