I know these cars can run forever, but this is rediculous! I changed the oil and secondary fuel filter last night. The car funs fine, I drove it a few miles, came home and with the key turned to the "off" position, the car continues to run! I had to block off the air supply to kill the engine. Any idea's?! Thanks in advance.

Greg
Lewisville, Texas

There are several threads on this problem. Check to see if you have inadvertantly removed a vacuum line from your shutoff or any where else in the area. It is a common experience to do this while changing filters, etc.

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Mike

2000 SL500 22,000 miles
1981 300CD 188,000 miles
1979 450 SEL 266,000 miles
2005 Cadillac CTS 25,000 miles

Greg,

As noted this is a very common problem, I doubt anyone with one of these machines has not had the same experience at least twice. Depending on the circumstances when it happens you can identify the problem more or less easily and fix it.

When you change the oil there are a couple of lines in the vicinity of the oil filter housing and they can be easily disturbed. Sometimes it does not take much to pull one of the hard plastic lines from a 20 plus year old rubber connector, or even crack the rubber connector. You should check to see there is a line from the vacuum source, a 3 or 4 way connector going into the firewall and one coming out that goes to a plastic fitting on the back of the injection pump. The lines are color coded and I do not have access to a vehicle to check right now, but one I think, is green and yellow, while the other may be brown. Someone else may pipe up with the actual color.

These two lines go to your starter switch. When you shut off the car, vacuum is used to close off the fuel supply. If there is no vacuum, there is no shut off and, since the fuel pump is mechanical, not electrically powered, the car will keep running. A few of us have taken great relief and joy in the fact that these cars will run without a battery or an alternator. Push start them and off you go. When in this condition you learn to park on hills.

Also as noted, if you use the Search function and enter a few words to describe your problem, you will find out this is often a subject discussed on this board. You will likely find more detailed descriptions of the parts in question.

Good luck, and I hope this helps, Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

Jim was on it.
The vacuum line to the shutoff valve on the back of ht epump is brown as well as the one that goes through the firewall from the vacuum pump connection that powers the shutoff.
You probably inadvertently pulled the one off the back of the pump or broke the rubber line connecting it to the shutofff valve.

When you tried to shut it off manually couldn'tt you use the "emegency" shutoff on the throttle linkage?
I had a problem with mine and it turned out to be the sring in the idle adjustment screw (side f the pump next to the motor). The spring had almost died so the best i could do by pressing on the shutoff was to slow the engine down but it would not shut off.

__________________
'99 S420 - Mommies
'72 280SE 4.5 - looking to breathe life into it
'84 300SD Grey - Sold
'85 300SD Silver - Sold
'78 Ski Nautique