I am having trouble starting my 240D if I try to restart after driving for a while. It just acts like it is not getting fuel. After repeated attempts it may start but will not run much faster than idle speed even at full throttle. If I let it set for about 10 minutes it starts and runs properly. I just bought the car and have notices that the fuel in the pre-filter looks very dark. I ran Diesel Purge through the system and the return flow turned the Diesel Purge black. Do I have air in the system, is the fuel contaminated, or is something else going on.

Any help you can give would be appreciated.

Bill

I would recommend changing all the filters if you have not already done that. Be sure to get the one in the fuel tank too.

Shortly after I bought my 240d years ago, it would barely go up hills and eventually, I found that the filter in my fuel tank was just a big black gob of junk. After changing that, it ran fine.

My car had only been driven in the winter when the owner stayed in California to avoid the snow in Chicago. She kept this car out here and another in Chicago.

It takes a special wrench to get it out of the tank. I ordered mine from a specialty tools company and it was not very expensive.

Thanks DCM. I'll give that a try. I've been wanting to get that nasty looking fuel out of the tank anyway.

Bill

amptique


You might want to look at your fuel tank filter to see if it will require that odd little wrench.

It is a shallow socket (about one inch deep overall outside, and the part that fits over the bottom of the filter is about 1/2" deep) with six sides and is 1/2" drive. It fits over the bottom part of the fuel filter that is visible on the bottom of your fuel tank.

Mine has "AST M 0035" stamped on the side and looks like it is about a 45mm socket.

I finally got the fuel level down low enough to drain the nasty black fuel out of the tank and replace the screen. I lucked out -- when trying to remove the fuel line that goes into the fuel screen the screen came out with it -- didn't need the special tool. Replaced the fuel, flushed out the lines and replaced all furl filters. Fuel in pre-filter looks much better but I still have the re-start problem.

If I stop the engine and try to restart it will not start. If I wait 1-2 minutes it starts normally. Any ideas?

Thanks,

Bill

amptique,

Has the problem you reported where the engine will not run above idle now matter how hard you press the gas pedal gone away or is it still there even with clean fuel? You may have two separate problems, so any changes in how the engine operates is helpful in figuring this out via cyberspace. 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,

I have not observed the problem with low engine speed at full throttle since I got the contaminated fuel out of the system. I'll see if I can reproduce that problem.

Bill

amptique,

Trouble starting one of these engines when they are fully warmed up is usually a problem with low starting rpm from the starter, and that is a consequence of how old, and how hard the starter has worked, over its life.

The issue with warm restart problems can also be caused by poor connections at the battery, at the battery ground, or the connections to the starter itself. So, I would check the connections first, since that is essentially free and you can do it at anytime you want, if you do it yourself.

Diesel starters typically see much higher loads, and crank longer than their gasoline engine counterparts. They therefore get a lot hotter from current flowing through the windings. Heat damages the insulation on the windings and when the combination of high ambient temps, a near end of life insulation condition and a Diesel come together, you can get the confusing symptom of a hard to start Diesel that is fully warmed up.

Is your car a manual? If so, try push starting it, and if it starts right up, the chances are the starter is weak and not reaching the critical minimum speed needed to get one of these engines to fire.

Be very selective about where you get your next starter. If you use FastLane (recommended) you will get a starter rebuilt by Bosch. That means it will have a new stator winding with new insulation that will last for a while. Also, get the one for the 1985 300D Turbo. It is called "heavy duty" while the one listed for the 1983 and earlier 240D is not. The starters are physically interchangeable and having a slightly more robust unit for the 240D will help you through the cold and last longer. Many rebuilt starters will have all the moving parts taken care of, but they will not pick up the insulation system degradation and will therefore not rewind the unit. They may dip it in insulation material, but that is not the same as rewinding as dipping will do little to help where the wire exits the slots, which is where most problems occur.

Good luck, and let us know how you make out on this one. 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)

I am having the same problem with my 240. When hot it does not want to fire up after sitting for 10 minutes or so unless you crank for about 5 seconds then stop and try again. Will fire right up the second time. I have replaced all the filters etc. If you crank for 20 seconds or so it will start but that seems to be excessive wear on the starter to me. Better to crank for 5 seconds, stop, and then crank again which will start without fail. You may want to try this.

Had a problem like this sometime ago, finally tracked it down to the primer pump knob on the injector pump had managed to unscrew itself, so no fuel pressure. I just turned the primer knob until it was tight again and "BANGO" problem gone.

Hope this your answer!!!!

Ben

On my wifes Honda accord I had similar problem. i am not sure if this will apply to diesel engines.
All I had to do was to open the gas tank cap let it vent for few seconds and recap and problem solved. Now every time it gives her a problem, I see her near the gas tank with gas cap in her hand.


Make sure all glow plugs are good anyway.
MVK

__________________
One penny saved is three penny earned.

1985 300D Turbo 179,000miles

amptique,

Your symptoms still the same? Car starts "cold" but not "hot" without some antics? The odd throttle response still there or is that gone now?

Seems to me a loose hand pump would affect the starting procedure every time, and it would leak a little fuel. Mine leaks if it is not tight.

My father-in-law had the vent line (goes to the right rear corner, behind the bumper) get gummed up and seal itself off. After driving some distance his car would not start or run well, and his fuel gage would get a little more irregular than these usually are. Things like the reserve light coming on with up to a full tank showing (correctly). When he took the cap off it was a task for someone just like him with giant hands. The thing would barely turn. While this could explain the "hot" phenomena, you have not noted any odd fuel filler cap antics or unusual fuel gage spasms. Might be worth a check though - does the gas cap make a noise when it comes off?

Keep us posted and good luck. 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)

Wow! What a great batch of suggestions.

I have not been able to check out the car to see if it still does the "full throttle but runs at idle speed" thing. I just checked the hand pump and I had forgotten to tighten it after replacing the fuel filters two days ago. When I open the fuel cap I hear a "Whoosh" sound so maybe the vent tube is clogged. I'll check that tomorrow.

I hope it is not the starter. It looks like a bear to replace.

Thanks for the help. I'll let you know how it goes.

Bill

Rebootit -- Tried the 5 sec. crank, stop, crank again -- no go.

Jim Smith, MVK -- I cannot reproduce the "throttle on full - engine at idle speed" thing. I think I got rid of that problem. I removed the fuel filler cap after stopping the engine and it still won't restart. The glow plugs have been replaced -- same behavior.

The car just like to rest for 1-2 minutes after you shut it off and then its ready to go again. Wierd!

Thanks,

Bill

__________________
Current Vehicles:
1990 Mercedes 300SE (147,000)
1985 Mercedes 300SD (203,000)
1983 Mercedes 240D (167,000)