seems to only want to go 60 uphill. Filters were changed.Tank filter cleaned. Nasty black diesel in the tank emptied. Valves adjusted. Purge done. Still the same problem. When i get up to 60 uphill i can floor it, it drops down and revs around 4k so i let off. Downhill when you get over around 72 you can floor it without it dropping down and it will speed up fine.
1983 300SD
Any ideas?

Follow every step in this procedure:

http://www.dieselgiant.com/mercedesaldaboostsystemservi.htm

Probably normal if the hill is steep.

Well yeah. Going downhill makes acceleration very easy for any vehicle and 72mph is too high for it to downshift.

even on hills that aren't that steep. if its long enough it will slow down to around 60. A week ago it was 65. week before that it was 70
will try the ALDA system service Brian.

Check for any leak on piping between pump & injectors, sometimes it's not visible untill pump is working at full pressure, & there is some fuel loss there.
If the symptom is power loss on hill climbing, check tightness of all bolts, & metal pipes integrity. any indetectable loss there makes some cylinder get off the row, loosing power.
Also, a pump checking (regulation/calibration) & adding an injector cleaner to fuel sometimes improves something.
Igor

alda makes the most sense, but you could easily have a worn engine that is losing compression. or a worn turbo that is failing. also you could have a simple air filter clogged up.

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

ended up needing a throttle linkage adjustment. Only was getting about 1/2 throttle. Good as new now!

This problem couldn't have happened overnight...........it must have been a gradually evolving issue ..........but, nothing wad mentioned in the original post regarding the slow onset of symptoms...........????

didnt even notice. Thought it was normal to go 75 uphill. When it got to 70 though figured it was a clogged filter. Changed it, did nothing. Then about a week later it couldnt go past 60 on the same hill. Now.. after the adjustment. 85+ no problem on the same hill. Feels like a rocket now just figured it was slow because it was a diesel.

How do you notice that yo need a linkage adjustment. Do you disconnect and see how far it will go free hand or do you have another system to check for proper setting.

You could move the Throttle lever on the side of the Fuel Injection Pump by hand to note the full range of movement.
Next have someone step on the Accelerator Pedal all the way down and see if the Throttle Lever moves the full range the same as it did by hand.

Other thoughts:
If that Bell Crank on the Fire Wall is going bad it could happen within a few days.
I do not have an SD but on my linkage there is a 10mm Bolt and a Kidney Slot in part of the linkage for adjustment. I remember over 1 year ago some one had that Bolt come loose and the Linkage slippe in the slot.
Same symptoms.

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84 300D, 82 Volvo 244Gl Diesel

Cause has always been lack of fuel whenever my SD wouldn't go. ie fuel filters, alda, algae (don't argue proper name). Guess I'll add throttle adjustment to the list.

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.