I have heard other diesels, when the throttle is "flicked" the engine RPMs will rise, then almost immediately fall to idle. My 240D is very slow at dropping to idle.

Listen here: http://www.youtube.com/watch?v=UWXSTEL8gnw

Any ideas?

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1983 240D 4 Spd - Only 289,000 Miles!

I'd check the idle control knob and adjustment of the cable. If it's cranked up it can slow the rpm drop. If that's not it check and lube your linkages.

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'83 240D

In addition to making sure the accelerator pedal and linkages are moving smoothly and not binding, also check for a broken or missing injection-pump throttle-return spring. This spring is attached between the throttle lever and a bracket behind the pump, next to the engine-block and it's Kind of a tight space back there, if you need to replace it.

Happy Motoring, Mark

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DrDKW

I guess the first thing to do would be to get a helper to press and release the fuel pedal. You will be able to observe if there is a delay in the action of the pump lever to return to it's lowest position.

If so and I expect there will be a delay it should prove easy to rectify. The linkage should be lubed and checked anyways just to make sure that the full action of the pump arm is being activated at full pedal deflection as it impacts available power.

This even if it is not sticking is one of the first things I inspect on these cars. You would probably be amazed at the number of 123s running around with less than the available full deflection of the injection pump arm available.

A lot of 240ds are abnormally slow because of it. The owners think it is normal I suppose. Remember you want everything you can get out of 240ds powerwise. Or most of us do.

I'll check that spring later, but the linkages move freely... I also have a lot of blow by.. enough to blow the oil cap off when loosened.

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1983 240D 4 Spd - Only 289,000 Miles!

Here we go. Has the car in the past or is presently using waste vegatable oil? If so the injection pump may be gummed up internally. Also the rings will need soaking down with miracle mystery oil to see if the blowby can be reduced. Wvo can create these conditions.

At some point with intense crankcase pressure from blowby the shutoff valve on the injection pump can be activated or partially activated.

The injection pump can be soaked down internally with laquer thinner if pump gumming is an issue. Expell all the dissolved junk through the relief valve with the primer pump after soaking rather than trying to run it through the injectors.

Also on the 83 240d there are two rubber sleeves on the horizontal linkage. Or supposed to be. If they have rotted off the full deflection of the injection pump arm cannot occur and available power is low as a result. Have a look for there presence and condition.

Alright thanks. I will check those in a few, I didn't think of the spring or pump arm. Idle knob is fine, need to remove the slack in the cable (not a lot). I dont recall seeing any rubber on the linkages, I could be wrong, and as far as the engine... should I inject a little MMO into the glow plug opening? Or I. Have also heard of people running 50-50 ATF and Marvel MO in the crankcase for a length of time, I forget how long though. Could this cause old gaskets to leak?

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1983 240D 4 Spd - Only 289,000 Miles!

Im thinking the idle is turned up to high, it sounds pretty fast. Try adjusting the idle a bit slower and I bet the revs will drop like they should.

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1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg

There is a little device in the linkage that acts as a vibration transfer reducer or to compensate for movement I would think. It looks kind of like two u joints engaging. If your powerplant is a 1983 240d you have this.

Anyways as the rubbers rot off the slack in movement transfer occurs. They are two small sleeves. The device is located in the horizontal linkage line that runs alongside the side of the engine.

Since you did not comment on if the car has seen or is seeing waste vegatable oil some of the suggestions may not apply to your car in general.

What fuel you run or has been run is important and relavent. Your total milage is really not that bad if it is the original total milage. There are many examples out there indicating 200k that have far more than your indicated milage.

Ok, I found the spring was detached from the injector pump, and is working much better, Idle was fine... will go out for a drive and get back with you guys. It runs diesel only and has only run diesel for as long as I know. I know a lot about engines, I am learning alot about diesels, this is my first, and I love it. I bought it because I needed reliability. Now, about that blow by...? Any advice? ATF and Mystery Oil in the crank case? Good or bad? I'm just looking for ways to clean it out, and make it perform its best. I really enjoy working on cars and I don't just "keep it running".

Thanks everyone!

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1983 240D 4 Spd - Only 289,000 Miles!

The rings gum up primarily with vegatable oil gummy residue. It will do no harm in my opinion to soak them down or treat them.

There just may be little if any results if the engine has been on diesel fuel all it's life. Worth a try though as it is an economical attempt. . You cannot know in advance if any improvement is possible. It would be interesting if there were an improvement and the engine had only used diesel fuel.

Many times posters arrive on site seemingly reluctant to disclose they are using wvo. So we go round in circles until the fact is disclosed. It is just that certain situations arise on wvo users cars that never seem to occur generally on fuel oil burners.

I would dump a liter or quart of miracle mystery oil in the base oil. Just do not overfill the level on the stick. Over the miles the solvent will clean up the ring grooves if there is any thing to clean. Your blowby just might also be general wear. Lots of these engines that have burnt only diesel fuel also have substantial blowby.