There wasn't a cap on K-Jetronic metering units as the (3mm inhex) screw inside is used to set the mixture.

There WAS a cap on KE-Jetronic engines (90 bhp, catalyst, this metering unit with the blue electronic/hydraulic unit like ERST units also have) because trying to adjust the mixture with the screw won't be good.


Vacuum leaks on K-Jetronic engines is a problem. But only between the flap in the metering unit and the cylinder head. The pipe sits outside, so it won't affect air/fuel ratio.