So I have 2 of these, they appear to be slightly different. One uses a different type of vacuum advance set up. the 80 has a physically larger advance unit that has 2 vacuum ports on it one on the front one on the back. the 83 unit has a physically smaller advance unit with 1 vac port. Both are from euro models with the M110 engine. Is one better than the other to use? Are they the same or different advance rates / amounts? As far as I know these were both from the 185 HP motors.

Doubt much difference at all.
The earlier one has vacuum advance & retard.

The later one has only vacuum advance.

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aah, Thanks. Any idea why they function differently? Does one have a mechanical advance return (spring) and one returns by vacuum alone? Also the timing on these cars should be set with both lines plugged in or un plugged? The base timing is listed as 2 degrees BTDC @ 650RPM on the radiator support tag, however it was added by the US importer on the 83, so I am not sure if it's correct. What is the optimum setting?

We always set the timing on EURO M110 engines to 32 BTDC w/o vacuum at 3500 RPM.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

thanks again for the info