850 Goes well when cold, plays up when hot
A friend of mine owns a 1997 850, 10 valve non turbo which runs well when cold, but once it gets up to full temperature (say after driving for 15 minutes) starts losing power, cutting out, it will idle but won't rev and seems like spark is being cut any moment the throttle goes beyond 1/4. It's like it's hitting ignition or fuel cut as you take off, first thought was air mass meter however this model uses a MAP sensor. At times it will idle real low (like 200rpm) and you have to shut it off, wait a few minutes then it will start and idle but again not want to rev. Once it cools down all is well again.
Unsure what to try.