Help for 240D injection issue? - PeachParts Mercedes-Benz Forum

BoiseBenz · #1 10-11-2009, 12:39 PM

My friend Oscar runs a repair shop, concentrating on MB gassers.

This particular car looks like a taxi in Beirut, but it has a three-year-old MB rebuild and a manual trans, and only 320k total miles with no rust.

Not long ago the owner's kid was driving the car, and "it suddenly quit." As it turns out, the car will start right up, but only if you floor it. Floored (or manually pulled to "full) it will run at about 1300 RPM (estimate). Gently releasing a little the car will drop to "idle" speed, and idle perfectly smooth, with no smoke or unnatural clatter--even when cold. Any lower/less it will stall. Basically, it runs like a dandy but the fuel selector seems to be set about 3500 RPM too low.

I'm suspicious that either something went haywire with the governor, or the kid was jumping it (?) and the rack skipped a few teeth. Any ideas? If it's not simple (read: "cheap"), the car will be scrapped.

Diesel911 · #2 10-11-2009, 02:48 PM

Pop Throttle Linkage off of the Throttle Lever that is on the Fuel Injection Pump. See if it will get higher rpms. If it gets higher rpms like that you have a problem somewhere in that Throttle Linkages preventing the IP Throttle Lever from moving enough.

Run it with out the Fuel Fill Cap on to see if it is a restricted Tank Vent.

Run a longer Fuel Inlet hose to a seperate container with clean Diesel Fuel; to rule out any problems to the rear of that.

Try changing the Filters

Check the Fuel Supply Pump Pressure and Fuel Output.

Diesel911 · #3 10-11-2009, 02:52 PM

Quote:

Originally Posted by BoiseBenz

My friend Oscar runs a repair shop, concentrating on MB gassers.

This particular car looks like a taxi in Beirut, but it has a three-year-old MB rebuild and a manual trans, and only 320k total miles with no rust.

Not long ago the owner's kid was driving the car, and "it suddenly quit." As it turns out, the car will start right up, but only if you floor it. Floored (or manually pulled to "full) it will run at about 1300 RPM (estimate). Gently releasing a little the car will drop to "idle" speed, and idle perfectly smooth, with no smoke or unnatural clatter--even when cold. Any lower/less it will stall. Basically, it runs like a dandy but the fuel selector seems to be set about 3500 RPM too low.

I'm suspicious that either something went haywire with the governor, or the kid was jumping it (?) and the rack skipped a few teeth. Any ideas? If it's not simple (read: "cheap"), the car will be scrapped.

The Fuel Selector Issue.
There is a screw on the other side of the throttle lever (opposite the idle screw side) that sets the Max rpm that the Fuel Injection Pump is supposed to operat at. Check that to be sure that the nut or screw did not back out. However, I doubt if this is simething that would happen suddenly.