Plenty written on EHA if you do a search.

Adjustment requires setting up fuel pressure differential measurements using guages with fine enough calibration. It is detailed in the Service CD.

Best done to the book by an indie in my opinion once you know all other components of fuel system are AOK.

I can't speak highly enough for how this has improved the feel of the engine.

It is resetting to factory spec (0.4 bar) with 0.45 bar being suggested to compensate for an older engine. It is slightly richening the mixture. It would sem that my car was previously running excessively lean.

It involves a micro-fine adjustment.

89 300CE 153k kms