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Discussion Starter #1
I have a 78 450sl. It had been stored for 6-8 years. Drained the tank, all 20 gallons. It didn't smell, or look bad at all. It came with a new fuel pump and filter. When I went to replace someone had put new on, at some point, replace them anyway. Did new plugs, wires, cap and rotor. Got the car running and took it for a ride in the neighborhood about 5 miles. Ran OK not good. Replaced all the injectors seals and the plastic things. THe old were really bad. Starts up and runs good cold but when it reaches operating temp it starts to go down hill fast. It looks like someone replace or rebuilt the fuel distributor. When I was driving it around the neighborhood discovering that it didn't run good when warm I slowly went by my wife walking the dog. She said the exhaust really smell bad like "stinky exhaust not gas. It doesn't stink when you first start it and let it run in the garage. Or when you get it home and let it idle when warm. BTW it will start right up when warm. Any thoughts?
Thank you
Kirt
 

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1984 380SL
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My 84 380 also sat for 5-6 years before I got to it. It took six months to get it running right. Put a couple of bottles of Techron in it and see if it doesn't improve. Your symptom of poor performance when warm also suggests a vacuum leak somewhere, a seal that ceases to seal when it gets warm and expands. Good luck!
 

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Discussion Starter #3
Thank you. I plan on going over everything on top of the engine with a fine tooth comb this evening. Was wondering, also,if it had something to do with the warm up regulator or start up valve maybe?
 

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2003 E320 4matic wagon; 1979 450 SL
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Just a quick thought. Probably too simple but an easy check. See if the auxiliary air by pass valve is screwed open enough. If your running good cold, could be that you are getting all the air through the auxiliary air valve which is temp operated ,open when cold and closed when hot. If the bypass screw is closed that would limit you air supply. I may have the component names wrong but I'm sure you know what I mean.
 

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Discussion Starter #5
Thank you. I will check it out later today when home. Didn’t have any luck finding a vacuumed leak. Btw. When I removed the injectors they were Terribly loaded up. Will try to attach pic. View attachment 2625645
 

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Discussion Starter #6
I tried the aux air valve and its ok. I got a kit and rebuilt the warm up regulator. Took it for ride and it warmed up and seemed to run ok for a while once it reached operating temp then it started stumbling at about 2500 rpm. It stalled at the end of the driveway when I tried to take it out a second time. Started right up and ran ok but stumbled after a bit at the 2500 rpm. This am I checked the plugs and it looks like its running rich. Judging from the injectors it has been running rich for a while. Any other suggestions? Thank you. Kirt
 
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