Greetings All,

This may seem like a non-educated question, but in light of poor acceleration from a stand still I'll ask it. All reference is made to a 1980 300TD non-turbo, and yes that's probably the reason right? At any rate, it seems slow to accelerate from a stand still, manually shifted or using the given choice of second by the tranny. Just wondering if there is some adjustment on the injection pump I should be looking at or adjusting or testing to see if the proper amount of fuel is being delivered or perhaps too much causing it to dog out on start out. After the shift to second done manually, RPM's seem to pick up and the shift from 2nd to 3rd is to quick (only maybe 7-10 MPH more)
Any input as to what the various screw adjustments do, besides the idle of course would shed some light on to what options are available for testing out different results it has on initial performance.

Thanks,


Charles

If this were a turbo car, there are adjustments that will effect this, but I suggest that you do not adjust any screws on the pump in a non turbo car.

Check the start of delivery(timing), adjust if necessary, and leave everything else alone.

Good luck,

There is a small white plastic vacum control valve on top of the valve cover that has three vacum connectors going to it,two on one side and one on the other. It influences the injection pump, automatic transmission and egr system. The part number is 002 997 53 36. Sounds like the problem to me.

Your transmission should start in first gear. The vacuum valves on top of the VC (as Dr Parts describes)initiate the 2-1 downshift as the throttle is taken up (before actual rpm increase).

Unfortunately the 80-81 240 and 300D only had vacuum shift; no control pressure cable. After the valves at the VC are working the shift points are changed by adjusting the length of the linkage from the proportioning valve to the throttle. (on the rear of the pump)

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Thanks You Guys for attempting to help but something isn't just right here. First off I know this engine probably was replaced from the original, and is still a non-turbo 617.912 at least the engine number proves it to be. The problem I am facing while reading these posts is this. The check valve looking item that Dr parts speaks about has no vacuum line going to the injection pump. The only line currently on the pump is the shutoff vacuum line on the rear of the pump. There is some sort of vacuum looking housing mounted on top of the injection pump with a metal tube coming off the side which looks like it should have some type of vacuum tube slipped onto it, but it doesn't. The same housing also has a screw on top of it for some type of adjustment. This item I wish someone would explain to me. Steve as an answer to your statement. If I leave the tranny in "D" from a dead stop it shifts twice only, which tells me it's starting out in second gear, very slowly I might add. If I manual put it in "L" I know I am starting in fisrt gear, and then shifting it to "S" it shifts to second and third, then moving it to "D" it goes into fourth.
I don't know if that helps determine any problems, but just to clarify what is actually happening. What's the vacuum looking actuator on top of the Injection pump for, and should there be a vacuum line hooked to it? If so where should the vacuum come from, before or after the check valve looking item?

Charles

That vacum looking box on top of the pump is called the "Adjustment to altitude" in the film I see the connector your talking about but the film dose not show any lines in this picture going to it. Sorry I'm just a parts guy not a tech.

Greetings all,

I know there are more suggestions or comments out there. Please post them.


Charles

Charles,

I know from experience that if the start of delivery is not right and the valves need adjusting, the car will feel almost powerless. You haven't mentioned whether these things have been checked. Suggest you start with basic tuning adjustments before going on a search for more subtle problems.

Good luck.

__________________
Ted
1979 240D
165,000 miles

Its hard to make recommendations when you can't clearly describe what you have. The metal line you describe sounds like the breather point for the altitude compensator (aneroid) as Dr. P stated. Nothing should be attached to it.

If you have an 80-81 you should only have vacuum shift control. If it doesn't exist then you either have a different tranny (earlier 300D trannies only had throttle/control pressure control via a metal linkage off the throttle to an arm on the pass side of the tranny) or you are running with NO control.

Verify which tranny you have as no diesel has power starting in second gear.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Thanks Ted and Steve for your replies,

First off for Ted, I did adjust the valves last week and noticed some engine performance that wasn't there before. The injection pump drip test hasn't been done yet, emailed parts shop requesting a part number for the drip tube but that was several days ago and haven't gotten a reply as of yet. Will ensure that the test gets done though. Could see how this would impact performance overall.
Steve, there is linkage that crosses over the valve cover to the passenger side then down along the side of the block to what seems like the front of the tranny. The throttle linkage looks pretty basic to me, one rod going to the injection pump, one crossing over the valve cover to follow along side of the block to the tranny.
Steve, by your input I am to assume that this is a linkage shift tranny only? What adjustments can be made to it in order for the shift pattern to be corrected, if any?

Thanks You guys for your input

Charles

can-do,

When you manually shift thru the gears is the acceleration still sluggish? BTW, you can manually shift all 4 gears even though there are only 3 positions on the gear shift ..... if you move the selector back to "L" as soon as it shifts into 2nd gear, the tranny won't jump into 3rd until you select "S" again. I had to manually shift my 240d in this fashion for a few days when the white plastic valve that Dr Parts & Steve mentioned failed. If I didn't know that the valve was the culprit, I would have more than likely assumed that I had a fuel related problem. If I left the vehicle in "D" from a standstill, it would have taken an eternity to get up to speed since it would go into 4th gear at about 25mph. Also, just curious if this a problem that developed recently, or has this been the case since you've owned the vehicle???

__________________
1980 Mercedes 240D
1982 Mercedes 300SD
1985 Mercedes 300D
1993 Dodge Cummins Turbo Diesel

As posted in the previous post this is apparently a linkage problem between the engine and tranny. If I shift manually from S to L to D everything seems to be fairly proper shifting wise, although the shift from 2nd to 3rd seems a bit fast and it can't be controlled simply because once you move the selector to L it shifts both 2nd and 3rd gears, waiting for you to move it to D for 4th. The speed difference between 2nd and 3rd is only 7-10 MPH if that, and it's begging to be shifted to 4th around 40-45MPH. The problem at this point is how to adjust the linkage so it shifts down to 1st gear when stopped and somehow delaying the shift from 2nd to 3rd to keep the RPM's up before going into 4th. I'd also like it to downshift automatically from 4th to 3rd while asending a hill, without dropping the pedal to the downshift switch. There's got to be a way to adjust the tranny to respond as it should. Seeing as it's a mechanical linkage, how's it adjusted.


Thanks,

Charles

You should shorten the linkage. You also will need to verify the proper function of the linkage due to your unknown combination. The linkages should have a slip joint in it somewhere. As the throttle linkage moves you should get significant movement of the transmission rod before any inj pump movement takes place. I don't think just a link adjustment will be enough, I presume you are not getting that pre-power linkage movement.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Greetings Steve,

Once again, I'm hunting in the Haynes manual for a pre power linkage. Where is it and what does it connect to? I see the linkage adjustments for the tranny, and after your explaination I see where I need to look and probably what needs to be done once found. Didn't find this prepower linkage though. Can you help me out on this one? After reading Ted's email I am assuming that the prepower linkage is the slip linkage on the power control rod that takes up the slack before actually moving the rod for the tranny shift. Is this correct in my thinking?

Thanks,

Charles

[Edited by can-do on 02-28-2001 at 08:28 PM]