420 SEL 1991 207K miles
 

I just had my spark plugs changed to NGK Iridiums. The old BOSCH ones were wet and black- running too rich? Where is the adjustment for this?

420 Sel Running Too Rich
 

I just had the spark plugs changed yesterday- 4 on the left bank were black and one was even wet and obviously not firing resulting in the rough idle and missing upn hard acceleration- right bank was better but still had black deposits and were not clean after less then 6K miles on the plugs-

How can I adjust this to a leaner mixture????

Thank you,
Mark

Next to the fuel distributor. a 2" tower that MAY be plugged.