300sd Diesel Shut Off - PeachParts Mercedes-Benz Forum

greazer2b · #1 06-20-2017, 05:50 PM

While trying to adjust my idle I broke off the adjustment screw. After thinking about how to repair I came up with temporary fix.

Went to Menards and picked up a spring 5 3/16" long,so it was perfect pull not to much but just right to set RPM at 850 for A/C mode.

To repair bolt I used to JB Weld to put back together then let sit overnight and then I used a insert that is used for screwing in particle board for shelving then filed the teeth so that it just fit in.
Then pulled out and filled with JB Weld after 24 hrs cure it set very well, the insert has 1/4"x20 thread so the bolt work real well.

But here's my problem: It won't allow me to shut off car

even with popping the hood I can't get the "Stop" to Stop. If I back out the bolt the linkage will allow me to push stop but therm I loose my idle.

I would appreciate help

Thank

tyl604 · #2 06-20-2017, 07:26 PM

Trying to visualize mine. Can you send us a pic?

Dan Stokes · #3 06-20-2017, 08:09 PM

I think I need a pic, too. My brain doesn't seem to be drawing what you're describing.

Dan

greazer2b · #4 06-20-2017, 09:04 PM

Quote:

Originally Posted by Dan Stokes

I think I need a pic, too. My brain doesn't seem to be drawing what you're describing.

Dan

Sorry for confusion. The adjustment bolt has a slotted head and nut that you losses and then put screwdriver in and slowly turn to add rpm. It sits tight against the engine side of pump, between Alda and glow plug on block.

John

ROLLGUY · #5 06-20-2017, 09:12 PM

If you re-used the bolt, it has a spring loaded end that allows the stop lever to move. If you changed the bolt, then there is your problem.

greazer2b · #6 06-20-2017, 09:50 PM

Quote:

Originally Posted by ROLLGUY

If you re-used the bolt, it has a spring loaded end that allows the stop lever to move. If you changed the bolt, then there is your problem.

Thanks RollGuy
Due to the break I was unable to just JB weld due to only having 1/4" surface on each side of bolt. Looking at the bolt I can see were a spring would sit.

I didn't find the spring end, plus have driven since it's my only car.
Would you happen to have?
John

ROLLGUY · #7 06-20-2017, 09:56 PM

Quote:

Originally Posted by greazer2b

Thanks RollGuy
Due to the break I was unable to just JB weld due to only having 1/4" surface on each side of bolt. Looking at the bolt I can see were a spring would sit.

I didn't find the spring end, plus have driven since it's my only car.
Would you happen to have?
John

I am sure I have a spare from a junk IP. I have seen this happen before, and the best fix is a piece of aluminum angle. It is not easy to do, but several people (including me) have done it successfully. It is fastened to the stop screw just to the right. There is a thread here somewhere, but not exactly sure where.

greazer2b · #8 06-20-2017, 10:04 PM

I thought of that, and was my back up plan however the new set up is spot on it hits the linkage. The bolt is a 1/4"x 2 1/2" machine screw.

So there's plenty of bolt under there that could hold a spring.

John

ROLLGUY · #9 06-20-2017, 10:33 PM

Quote:

Originally Posted by greazer2b

I thought of that, and was my back up plan however the new set up is spot on it hits the linkage. The bolt is a 1/4"x 2 1/2" machine screw.

So there's plenty of bolt under there that could hold a spring.

John

You need to use the factory adjustment bolt if you want the stop lever to work properly.

greazer2b · #10 06-20-2017, 10:43 PM

Quote:

Originally Posted by ROLLGUY

You need to use the factory adjustment bolt if you want the stop lever to work properly.

I still have the bolt? The end of the bolt is rounded smooth about 1" long, so I thought another bolt in same place would work....however it didn't as you have pointed out due to not having a spring .

How long is the spring? Can't I slide it up on the bolt and have it ride on linkage?
Sorry I am not questioning your experience I am yet ring to understand.
John

ROLLGUY · #11 06-20-2017, 11:10 PM

Quote:

Originally Posted by greazer2b

I still have the bolt? The end of the bolt is rounded smooth about 1" long, so I thought another bolt in same place would work....however it didn't as you have pointed out due to not having a spring .

How long is the spring? Can't I slide it up on the bolt and have it ride on linkage?
Sorry I am not questioning your experience I am yet ring to understand.
John

The bolt is very special, and nothing will take the place of it if the stop lever is to work properly. It has a plunger with a spring. The spring is stronger than the throttle return spring, so when it is adjusted, it raises the idle speed without compressing the spring inside the bolt. Only when the stop lever is pressed, does the spring inside the bolt get compressed by the plunger. If your bolt is missing any of it's parts, it will not work.

greazer2b · #12 06-20-2017, 11:20 PM

Quote:

Originally Posted by ROLLGUY

The bolt is very special, and nothing will take the place of it if the stop lever is to work properly. It has a plunger with a spring. The spring is stronger than the throttle return spring, so when it is adjusted, it raises the idle speed without compressing the spring inside the bolt. Only when the stop lever is pressed, does the spring inside the bolt get compressed by the plunger. If your bolt is missing any of it's parts, it will not work.

So I will need to redo what I have done. I still have the bolt and nut. Could you let me know when you find a spring.
I had a feeling that the tapered bolt was very unique as are a lot parts on these cars.

Thanks RollGuy

ROLLGUY · #13 06-20-2017, 11:22 PM

Quote:

Originally Posted by greazer2b

So I will need to redo what I have done. I still have the bolt and nut. Could you let me know when you find a spring.
I had a feeling that the tapered bolt was very unique as are a lot parts on these cars.

Thanks RollGuy

The bolt, spring, and plunger are all one assembly. It does not (should not) come apart.