Misfires In Warming-Up Phase, No Throttle Response Cold

Cause/Remedy:

Deposits on inlet valves (coking).

Determine condition of valves by illuminating. Testing and Inspection Clean valves with deposits with jet cleaner. If no jet cleaner is available, clean valve when closed with an appropriately ground screwdriver. Remove injection valves on engines 116 and 117 for this operation.

The edges of the scraping tool must always be rounded off, to prevent score marks on the valve and valve stem when scraping.

After scraping, remove deposits with compressed air.






Operation note for engines 116 and 117:
Prior to sand-blasting the valves, simultaneously remove all rocker arms of the inlet valves to ensure that the valves are closed. Do not confuse inlet and exhaust valves, see diagram.
Individual removal of the rocker arms can lead to damage in the cylinders during subsequent starting of the engine due to granulate deposits.
For this reason, carefully inspect intake manifold and all cylinder bores for granulate remains after and-blasting.