E34 540i cutting out

[kcld]

I have a 95 540i that 'cuts out' over 3000 RPM until the engine has been thoroughly warmed. It was even an issue when the weather was warm but now that winter has set in I need to drive for 15 minutes - well past the temperature guage registering normal - before the engine will rev past 3000. I believe I read somewhere that the engine management system will limit RPM's until the engine is warmed but this 'cut out' is on the verge of violent, it appears to be shutting down the ignition entirely until the RPM's drop below 3000. Since this usually occurs under moderate load it results in the whiplash effect! I had a crankshaft positioning sensor go out a few weeks ago and replaced it, but the bucking continues... Any suggestions on where I should look?

[yoyo1]

Hi, you could try the Air Mass sensor, mine was gone & it felt as though the car was carrying 4 tons it was so underpowered & would not rev cleanly at all
HTH

[atv087]

hey yo yo wheres the air mass sensor on these cars

[yoyo1]

Originally Posted by atv087

hey yo yo wheres the air mass sensor on these cars

Hello,
Its just after the Airbox & it has a lead coming from a round socket mate.
Good Luck

[kcld]

Thanks! I'm leaning toward the intake leak as has been suggested. Very temperature dependant, it's fine in warm weather. The 'check engine' light comes on and the engine just shuts off until the revs drop below 3000 or so when the temperature is colder. Once the engine warms up thoroughly, it's fine.

[yoyo1]

Originally Posted by kcld

Thanks! I'm leaning toward the intake leak as has been suggested. Very temperature dependant, it's fine in warm weather. The 'check engine' light comes on and the engine just shuts off until the revs drop below 3000 or so when the temperature is colder. Once the engine warms up thoroughly, it's fine.

Temp related could also be Air temp sensor (on Inlet Manifold)or there are 2 Temp sensors 1 is engine Coolant Temp & has a white plastic connetor & the water Temp Sender Which right next to the ECT which has the black plastic connector. Thes are situated behind the engine on the waterbox which joins the 2 heads together , to see this you have to remove the Diagnostic plug & it is down ther, to get at it you have also remove the header tank on the bulkhead which is held in by 2 10mm bolts
HTH