MB E320/300e 24 valve, 6 zyl 104(980) engine, CIS-E

My learning and costly experience might help other in the same predicament.

ive finally found the causes of intermittent bad idling sometimes near stalling at stop, hesitation after half hour driving, black smoke with lack of power, accumulation of black soot on exhaust
caused by incomplete combustion, black plugs which always gets fouled.


1. intermitent idling is caused by oil leaking into distributor from
bad O ring and front timing cover oil seal causing short circuits.

I suggest that before spending on a new cap and rotor (both being very durable), prioritize new plugs, high tension wires and
and oil leak. i thought that the warm hesitation and loss of power is due to bad coil but anyway, i would suggest changing the ignition coil.

2. i have look into the EHA current and even measured it and tried
driving it with and without EHA connected but just the same there is warm hesitation after 1 hr driving with black smoke and cant even drive into a high driveway and with EHA current within normal range

Problem: bad fuel filter.

After long drive, filter gets clogged causing probably low pressure
and the ECU compensates by richening fuel and causes fouling of plugs, black smoke and soot and my fuel consumption drops from
4-5km/l to 2-3km/l.

Savings: I dont have to change my harness which i
rewired with the help of an electrician.
MB tech. told me that rewiring is not compatible with MB


In Summary, i suggest changing all that i have mentioned
and probably you could include OVP. Also wash/clean your exhaust of all the black soot it has accumulated because of poor engine performance


I HAVE A NEW MODIFICATION TO IMPROVE RESPONSIVENESS (which i have accidentally discovered from my vw golf when i
revise its vacuum tubings with a pneumatic connectors)

Place a pneumatic connector on the tubing going into the EZL
AKR ignition system. ( can also be used for cars with mechanical advancer). This connector is a one way check valve which maintains a higher vacuum into the ignition causing the engine to be a little bit advanced in timing.