300TD throttle linkage

[Junkman]

The throttle response feels sluggish and I'm starting on checking throttle linkage. Other things like fuel filter, valve adjustment, clear boost banjo have been addressed so let's deal with the linkage in this thread.



I must not be understanding the FSM correctly as mine appear drastically different from specs. See the pages from the attached FSM.


I began by disconnecting the linkage and checking current measurements.
For example, my connecting rod 14 is short and only measures 100mm from the wide part of the connection to the other.


If I'm reading the FSM correctly, standard specs should be 140mm for connecting rod 14. There isn't that much adjustment in the linkage. My linkage matches the diagram on the 1st page - even part 34 which is one way to confirm the correct diagram.


What am I missing re what the specs should be?

[300TD1982]

Originally Posted by Junkman

The throttle response feels sluggish and I'm starting on checking throttle linkage. Other things like fuel filter, valve adjustment, clear boost banjo have been addressed so let's deal with the linkage in this thread.



I must not be understanding the FSM correctly as mine appear drastically different from specs. See the pages from the attached FSM.


I began by disconnecting the linkage and checking current measurements.
For example, my connecting rod 14 is short and only measures 100mm from the wide part of the connection to the other.


If I'm reading the FSM correctly, standard specs should be 140mm for connecting rod 14. There isn't that much adjustment in the linkage. My linkage matches the diagram on the 1st page - even part 34 which is one way to confirm the correct diagram.


What am I missing re what the specs should be?

Was your car repaired with junkyard parts? Mine was, and I had an impressively mismatched setup that made troubleshooting... interesting. I ask because on p20 of 30-300 they show that rod as being 100mm, but that's for a USA 123.1 or USA 126.120 starting 1981.

[barry12345]

First things first. If someone presses the pedal inside the car down. Then the arm on the injection pump hits the stop. Is observed by you.


The linkage is not the problem. At least for low power output. The linkages from year to year did not remain the same on these engines.

[Diesel911]

Originally Posted by Junkman

The throttle response feels sluggish and I'm starting on checking throttle linkage. Other things like fuel filter, valve adjustment, clear boost banjo have been addressed so let's deal with the linkage in this thread.



I must not be understanding the FSM correctly as mine appear drastically different from specs. See the pages from the attached FSM.


I began by disconnecting the linkage and checking current measurements.
For example, my connecting rod 14 is short and only measures 100mm from the wide part of the connection to the other.


If I'm reading the FSM correctly, standard specs should be 140mm for connecting rod 14. There isn't that much adjustment in the linkage. My linkage matches the diagram on the 1st page - even part 34 which is one way to confirm the correct diagram.


What am I missing re what the specs should be?

When I did mine I measured from the center of the linkage socket to the center of the socket on the other end as best I could and mine has run OK since that time.

Also the pdf posted has one page but there is a lot more pages to it showing the other linkages. It is up to the reader to read which linkage is for his/her model.

The part on the fire wall that the linkages pivot on is also known to fall apart behind the metal plated.

[Junkman]

The arm hits the stop when the pedal is pushed down. I also observed that there is only a small amount of pedal movement before the linkage can be seen moving.

@Diesel: yes, I was measuring from the center of the ball to the other center on the other end. I posted 1 page because the complete file exceeded the forum size limit. I'll go back to make sure that it is the 1st page that applies to this car.

An 85 TD is a 123.193 which is what's indicated on p1 of the file. The linkage diagram matches the linkage at least where it attaches to the firewall. I'll look for the same attachment with different length specs.

[vwnate1]

Might you have the PDF chart for a 123.123 ? . mine is a 1982, should be same as 1981 .

TIA,