M20 hesitation when not warmed up

[DaveVoorhis]

My '90 525i (M20B25) consistently hesitates very briefly when accelerating from stopped after it's warmed up for about five minutes or so, and when the outside air temperature is less than about 5 degrees C. It's not enough to be more than vaguely irritating, though it did stall once when I was a bit heavy on the throttle. It doesn't do it when the engine is completely cold, or after about ten minutes of running.

Any thoughts on what might be causing this?

[Bill R.]

housing area and cleaning the terminals with some deoxit d5 or similar electrical contact cleaner, clean both the terminals on the sensor as well as the contacts on the plug too. On the ones i work on i then treat them with stabilant 22 contact enhancer, it helps to keep it from reoccurring. However if you don't have some stabilant the just using a contact cleaner like deoxit d5 should help alot. This problem i see when the engine isn't full cold but isn't warmed up either. Only at that midpoint. Only the ones i see it on will stall if you give them too much gas too suddenly while this is happening.




My '90 525i (M20B25) consistently hesitates very briefly when accelerating from stopped after it's warmed up for about five minutes or so, and when the outside air temperature is less than about 5 degrees C. It's not enough to be more than vaguely irritating, though it did stall once when I was a bit heavy on the throttle. It doesn't do it when the engine is completely cold, or after about ten minutes of running.

Any thoughts on what might be causing this?