1985 SEL500 Rinning rich/ Black soot
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Junior Member
Joined: Mar 2012
Posts: 21
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85' 500 sel
1985 SEL500 Rinning rich/ Black soot
Can anyone advise me as to why my mb may be running rich? Here are the details.
Purchased this car 1 week ago with a "lean" condition. Bought it from a MB mechanic. He said that it could be the fuel metering piston in the TB. I got it home and looked for blown fuses, found one ontop of a relay. and changed it. The car responded with more power. Could be a coincidence as I have no idea what that fuse was for.
One week later I have a car that is running rich. I take it out on highway and "blow it out" No smoke after punching it but when i return to city driving I get a huge ploom of sooty hydrocarbons out the tail pipe.
This car makes a few odd noises one of which I believe is linked to the fuel system. Ther is an intermittant whirring noise coming from the trunk. I believe this maybe the fuelpump.
The car was a shop car but sat since aug of this year, oil clean, clean air filter, clean pcv filter , I boldly assume the fuel filter i new also. The car runs awesome and no engine noise except for a noisy lifter on passenger side bank.
I ran marvel through the first tank as an attemt to clean it out. My question is;
Is this potentially a fuel system problem or a result of a car that needs to go out for a long highway ride to clean it out?
suggestions?
thanks
Purchased this car 1 week ago with a "lean" condition. Bought it from a MB mechanic. He said that it could be the fuel metering piston in the TB. I got it home and looked for blown fuses, found one ontop of a relay. and changed it. The car responded with more power. Could be a coincidence as I have no idea what that fuse was for.
One week later I have a car that is running rich. I take it out on highway and "blow it out" No smoke after punching it but when i return to city driving I get a huge ploom of sooty hydrocarbons out the tail pipe.
This car makes a few odd noises one of which I believe is linked to the fuel system. Ther is an intermittant whirring noise coming from the trunk. I believe this maybe the fuelpump.
The car was a shop car but sat since aug of this year, oil clean, clean air filter, clean pcv filter , I boldly assume the fuel filter i new also. The car runs awesome and no engine noise except for a noisy lifter on passenger side bank.
I ran marvel through the first tank as an attemt to clean it out. My question is;
Is this potentially a fuel system problem or a result of a car that needs to go out for a long highway ride to clean it out?
suggestions?
thanks
Junior Member
Joined: Aug 2011
Posts: 25
Likes: 0
87 560SEC (Euro)
Lots of issues could cause a car to run rich that you can diagnose using a fuel pressure gauge. You can adjust the mixture by using a 3mm hex key. The mixture screw is located on the air flow meter beneath the tower.
Google Bosch K-Jetronic testing.
Google Bosch K-Jetronic testing.
