Hi John

I have an 89 300ce with 153k kms. I have similar symptoms in an otherwise perfect car.

Starts well when cold but starts and dies when warm unless a bit of throttle is used.

Like you I notice that it can be rough on warm start up like it is missing a cylinder or two for the first few seconds.

My indie tells me I need new injectors. After proving everything else in the fuel system including adjusting the EHA which has transformed the driveability to 'as-new' this is the only thing left that makes sense for remaining symptoms.

It seems like the old injectors can leak down which in effect floods the engine. You are right that it is probably one or two cylinders. When additional throttle is used the engine has the air to burn it off.

The injectors for this engine a reasonably cheap and it is a reasonable DIY job.

Please let me know if you make the change.

89 300CE