How much slack should be in the throttle? On mine, there is 3/4 in travel of the pedal before it actually starts to move the linkages. Is that too much slack?

__________________
85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

What you want to examine is if the linkage on the pump is being totally advanced. Usually with that much input slack it is not. Usually just an exerecise in examining the total linkage to find any fault.

I shortened the throttle linkage rod to its max and the slack feels like it is less. I suppose there has to be some slack so that engine movement do not actuate the throttle. The remaining slack that I can't adjust out is probably due to worn pedal mechanism, bushings etc. How do I get the panel off to expose the pedal rod?

__________________
85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Our '83 300D is the same way, I haven't really looked into adjusting the linkages yet....its not being actively driven. I'm going to try and adjust them sometime soon though.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

I am not sure about the throttle linkage arrangement on a 300D, but on 240Ds that fix you mentioned won't actually "fix" the problem. It may make the engine race like a banshee.

On a 240D there is a joint at the throttle linkage pedestal hanging off the valve cover. In that section a link that normally has a nice tight connection that employes a rubber pad with two slots in it that is bonded to a metal plate and engages two rectangular cross section prongs. The rubber is eventually mutilated by the environment under the hood. The rubber actually falls off and you are left with a very sloppy fit between the slots in the metal plate and the metal prongs. Taking up the slop in the system by changing the length of the various rod may pull the linkage over one way or the other, but it does that at the expense of throttle travel. What you want is the full throttle travel when you are done, and no slop. On a 240D I fixed this with popsicle sticks wedged in the slots to tighten the fit, wrapped in electrical tape. Another member of the board added some wire to prevent the parts from eventually becoming loose and falling out, which works fine.

So, make sure you what ever you are doing, you end up with something that doesn't leave you with limited throttle travel at the injection pump. 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)

I'm wondering if this hasn't happened to my '81..

Driving home from work, it seemed as if mashing it to the floor wasn't 'enough' to get her going.. I drive the expressway home, and was getting passed in the slow lane.. (about 60-65mph)..

I looked under the hood today at the linkages.. There are two that attach to the top of the valve cover.. The front one has about a 1/4" of slack in it.. I unfortunately never paid attention before this, so I'm wondering if there's supposed to BE slack in it-- or not..

It looks like a small 'barrel' over the linkage rod-- and the bolt is slipping in and out of there.. Not sure if this makes sense-- it's the best I can describe it..

AJ

__________________
Agnes (the Limo) '84 300SD
Pearl (the Taxi) '81 240D (preparing for the 'afterlife')
Bridgette (baby girl) '82 VW Pickup-- currently getting readied for her rebuilt (overbored) engine.
1 VW 1.6 NA diesel **not installed in vehicle**
Gidget (the bimbo) '87 VW Cabriolet-- the diesel engine it above is eventually going there!

and a BMW Motorcycle. (1998 R1200C)

Did I mention I'm of German Heritage??

The 240D linkage problem I tried, and after reading it a minute ago I would say failed, to describe is mechanically obvious if you have someone step on the throttle pedal while you watch what happens. The side connected to the throttle pedal (the side with the two male prongs) moves through quite a bit of the available arc before it begins to move the injection pump side (with the two female slots). The fix is to make this connection pass torque from the throttle pedal side to the injection pump side for the whole stroke on the throttle pedal side. Different arrangements from year to year and 240D to 300D may exist, but the philosophy is the the same. My father-in-law's 1980 or 1981 240D is somewhat different, but his had a failure of the ball joint support for the throttle pedal side at the firewall. The fix was to buy and install a new ball joint there in his case. In my case the real solution is to buy a new female assembly, however, I don't think you can buy just that part. So, I run with the popsicle sticks.

Good luck and I hope this helps. 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 guess I'll try taking the 'popsickle' stick route-- and see if that 'diagnoses' the problem.. I just don't remember that slop being there-- but I guess I wasn't smart enough to photograph it, or whatever-- BEFORE I had a problem..

Hindsight.. (sigh)

__________________
Agnes (the Limo) '84 300SD
Pearl (the Taxi) '81 240D (preparing for the 'afterlife')
Bridgette (baby girl) '82 VW Pickup-- currently getting readied for her rebuilt (overbored) engine.
1 VW 1.6 NA diesel **not installed in vehicle**
Gidget (the bimbo) '87 VW Cabriolet-- the diesel engine it above is eventually going there!

and a BMW Motorcycle. (1998 R1200C)

Did I mention I'm of German Heritage??

Much to my happy surprise-- It was the accelerator pedal, at fault..

After looking at 'rigging' a temporary fix I got it the car, and noticed the pedal didn't look right.. It pretty much came out when I looked at it.. I took it around the block, and she was back to the anemic performance I'd become accustomed to!


Is it secured with anything.. I didn't find any screw holes, in the little metal plate at the base of it.. The top part of the pedal looks like it travels up and down a rod on a plastic sleeve..

Anyway-- I'm still considering this good news, since I did a quick out to the expressway... and in a few minutes I was doing 75/80, which is sometimes required "out there..."


AJ

__________________
Agnes (the Limo) '84 300SD
Pearl (the Taxi) '81 240D (preparing for the 'afterlife')
Bridgette (baby girl) '82 VW Pickup-- currently getting readied for her rebuilt (overbored) engine.
1 VW 1.6 NA diesel **not installed in vehicle**
Gidget (the bimbo) '87 VW Cabriolet-- the diesel engine it above is eventually going there!

and a BMW Motorcycle. (1998 R1200C)

Did I mention I'm of German Heritage??