Stone cold, my M130 MFI (1971 280SE) starts instantly at the turn of the key, high idles super smooth then kicks down and chugs. It chugs along roughly for about 3-5 minutes warming up, reaches a changeover, then idles smoothly from then on. Once warmed up it runs like a Swiss watch. I seem to recall there are some temperature or vacuum related transitions until the thermostat opens and running temp is reached. I can’t remember if this was ignition or vacuum related. Any thoughts?

__________________
Present
1971 280SE W108

1967 250SE W111
Rhode Island
_____________
Auf Wiedersehen
1972 280SE 4.5 (AKA Das Moneypitten)
1972 250C (Mit den zwei carburetors from hell)

"Time fly’s like an arrow, fruit flies like a banana" Groucho Marx

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Neither .. it is coolant temp related . The warm up device is on top of the injection pump and this allows outside air to be drawn into the engine through an air slide valve . This is the part with the 2 coolant hoses attached to it. The first check would be the inlet air filter at this device. They get clogged and this results in an overly rich air/fuel mixture during warm up. It is the round cannister at the rear of the device.
Check that first and repost finding..

Thanks Arthur,

Now, any tips on getting that breather off to clean it up or replace it? The big nut between the breather and the pump body, doesn't seem to lend itself to getting a wrench on it as it is slightly lower than the pump body and the right size wrench is too fat to get on the nut. This is the horizonally mounted breather next to the coolant inlet I'm after.

http://home.comcast.net/~macs4life/mfi2.jpg
http://home.comcast.net/~macs4life/MFI1.jpg

What am I missing? My shade tree mechanic skills are mighty rusty due to a multi-year hiatus.

Many thanks in advance.

Ps. Credit: Pics borrowed from a functioning pump for sale on eBay by the seller "280slpagode"

http://cgi.ebay.com/ebaymotors/Bosch-Fuel-Injection-Pump-for-Mercedes-280SL-280SE_W0QQitemZ4653020035QQihZ002QQcategoryZ34198QQrdZ1QQcmdZViewItem

__________________
Present
1971 280SE W108

1967 250SE W111
Rhode Island
_____________
Auf Wiedersehen
1972 280SE 4.5 (AKA Das Moneypitten)
1972 250C (Mit den zwei carburetors from hell)

"Time fly’s like an arrow, fruit flies like a banana" Groucho Marx

You need a thin wrench.
You can also tell if it is working with a rubber hose .. you put one end up to the filter and the other end in your ear.. you can hear air being sucked in when it is open [ warm up temps ] , and then it should close off completely at approx 156 degrees.
The advantage to removing it is you can clean it and you can also put your finger over the port to make sure the air slide is working, but the hose works too..
If this all works , the a/f mix at warm up temps can be adjusted by adding removing /shims on the mount of the Device..but before that is attempted , all linkages shoud be adjusted to spec first.