So if you have seen my last few posts. I have finaly completed fixing the vacuum system and retimed the distributor. She runs so much better. 1st time I took her out, one of the 4 way connectors on the vac. broke, causing a rough idle and starting problems, got that fixed and she purrs now.
Has anyone else run into this problem, I timed the distro. at TDC at idle, +13 at 1500 rpm, and +25 at 3000 rpm, all without vac advance. The book lends itself to be believed that once these adjustments are made and the vac hooked back up, the timing should advance to +11 to +15 degrees at an idle. However, when I hooked my vac line back up, it stayed at TDC, as soon as you touch the throttle, it advances properly at the specified rpms, and when unhooked it has remained the same for the specs without vac. It doesn't seem to pull vac at idle, but the slightest touch it starts to produce. Any ideas or previous fixes with this issue, that you may have had are appreciated. Maybe, I'm just out of it today also.
Gen II 1985 MBZ 500 SEL with R117 engine, 182,000 miles.
"I swear this thing still had the original spark plugs in it, when I got it a year ago".

Thank you and see/post again when I return from Afganistan.

You have the advance hooked to ported vacuum instead of manifold vacuum. I have an 84 500SEL and find that the engine doesn't care which way it is hooked up. If it runs good, idles good, and starts good then leave it alone. Something I learned just a year ago or so, these engines are designed for Regular gas and mine actually gets better MPG and seems to run better with it. TDC is the correct setting.
By the way, the 85 is a generation I, 86 and later are generation II.

Paul

__________________
84 500 SEL (307,xxx miles)

Paul,
Thank you for your reply, however, according to the manual, I am hooked in the way Mercedes wants it. I will give it a change to manifold vacuum, from the thermal vac valve that is shown.
Also, the Irvine Mercedes Classic Center says that due to it being built in 10/85 and shipped in 11/85, it was manufactored after the switch to Gen II, thus it is a Gen II.
As with any switch in bodies or generations, it has most elements of the new
(Gen II) model year, with a few artifacts of the previous (Gen I) model year.
This is what they have said, but I still haven't heard of a visual way to tell the difference, could you provide input. Thank you.

I don't know about the change over from gen1 to genII starting in 1985. If you are looking for parts for a US car, 84 and 85 500SELs are together and 86 to 91 are together. My 84 was made 11/83. An 85 parts car was made 11/84. They are the same car as far as I can tell. Your discription of the dist in your car is the same as a GenI. GenII cars has a dist without vacuum and mechanical advance. All timing is done in the ign control moduel. The fuel system was different also. 84 and 85 use a warm up regulator and a frequency valve. GenII used a EHA valve on the fuel dist and temp sensors. I don't have an 86 parts car but I do have a 89 and a 90. On the 84 and 85 the rear control arms are cast aluminum and the 89 and 90 have stamped steel control arms. On the 84 and 85 the differential (sp) is bolted solid to the rear subframe. 86 and later the diff is mounted with rubber mounts. 84 and 85 exhaust was a single pipe with 2 cats (one small and 1 large) and 2 mufflers. 86 and later used a larger pipe and converters going into 2 wing mufflers than 2 pipes to a single rear muffler. All mercedes have 2 pipes coming out the rear of the car. Thats about alll I can think of but if you have a question maybe I can help. If your car was made 10/85 it shoud be a 86 genII. Is your car by chance a gray market car or Euro car? All the cars I have been refering to are US cars.

Paul

__________________
84 500 SEL (307,xxx miles)

Some visual differences:

Gen1 cars' protective strips along the bottoms of the doors have ribs. Gen2 is smooth.
Gen1 cars' trim piece around the headlight switch has painted markings. Gen2 is backlit.
Gen1 cars' automatic climate control's auto fan button is thin and clear. Gen2 is black and the same size as High and Low fan. There is also a recirculate switch.

-J

__________________
1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

Generation 1 cars have 14" wheels, Generation II car have 15" wheels.
Paul

__________________
84 500 SEL (307,xxx miles)

This is what I think may be the case.

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]