1985 300 SD couple of questions - PeachParts Mercedes-Benz Forum

yuke · #1 12-27-2014, 05:17 PM

For one my neutral saftey switch is acting up in that sometimes it will not turn over unless I move the selector front to rear couple of times till it finally catches. I think the problem is with the bushings in selector lever which I have heard is a real pita to replace and there might be 6 of them so in meantime I was thinking if I could bypass nss by connecting 2 purple wires so it wou lt would start in any position problem is I can not locate it. I looked above to right of gas pedal and all I see is a hard plastic covering that I cannot move or see behind. Is the junction box with 4 or 6 wires behind there? If so I might just cut it out to get at the box. Also just got done adjusting the valves now car seems to have less pep and lower top end have to push hard to hit 85mph. My valves might be a little on the loose side heard that was better then to be on tight side would that cause a loss of pep?

Partscarver · #2 12-27-2014, 05:43 PM

http://www.peachparts.com/shopforum/diesel-discussion/250060-240d-adj-valves-llost-power-re-adj-got-power-back.html#post2171563

no comment on the replies...

vstech · #3 12-27-2014, 05:44 PM

Three things cause power loss.
1. Linkage adjustment/placement.
2. Valves adjusted too lose/wrong valve lash... I.e. Intake valve got exhaust setting and vice versa...
3. Turbo/Alda line dislodged.
Also, if it's been a while, fuel filters clogged can seriously slow down the vehicle.

dude99 · #4 12-27-2014, 05:44 PM

You heard wrong, its better to have the valves a little on the loose side as they tighten over time. I would suggest readjusting them.

I would suggest replacing the bushings as to bypassing things. Your car will become progressively harder to find the right gear in as the bushings wear. Also, I could be wrong, but I think that the automatic NSS also houses the reverse light switch.

Which brings us to the other reason to replace the bushings, to make sure that the reverse light switch continues to be activated in the correct position.

vstech · #5 12-27-2014, 05:48 PM

As for the linkage, there are only two That directly affect the nss. And unless the shifter itself is sloppy, only two are needed.

They are not easy to change, but not difficult either. The trick is to take the trans lever off first, then change its bushing, then do the shifter one.

yuke · #6 12-28-2014, 05:07 PM

Thanks 4 replies dude 99 you misunderstoo me I did adjust them all a little lose rather then tight as I do know they will tighten up on their own over time seems exhaust will tighten more then intake. I might have gotten an intake mixed with an exhaust but I did recheck and do not think that happed. Vstech thanks for the 3 main things to look for. I will take a close look at throttle linkage. When I get some time I will have to check my 0-60 time. Also want to unhook my alda and see if there is a difference maybe it is not getting the signal to dump more fuel. I did take the banjo bolt off rear of intake and it was clear with no leaks to switchover valve but that does not mean signal turbo boost is getting thru. Want to hook up a boost gauge but did not get to it yet. I do think that with car running properly it should do 0-60 in 14 sec. And should be able to hit 100 mph w/o too much effort. Right now I hit 85 on the flats. Just want the car to run its best as I use it daily for my 50 mile commute. When I get a chance I will post some pictures of things under the hood to get a better idea of the purpose they serve.