Major safety warning for EVERYONE!! Accelerator sticking..
 

My cruise control wouldn't work right recently. It would sort of want to work, but wouldn't. I heard it could be the amp.

My mechanic looked at it when the car was not running. He played with the metal linkage shafts that throttle the car. When he pushed it forward a lot, .... it stuck. It wouldn't release. He had me get in the car and floor the gas pedal. It stuck.

WHOA!!!

Good thing I don't floor it when driving, that could have easily been a major traffic accident, for me and others, like the Lexus incidents!!

He took the linkage apart to see which part was sticking. We sprayed the linkage with silicone (since it doesn't go away like WD 40 does) which stopped the problem, and got my cruise control working again.

Please, lube your fuel linkage.

Jeff 1991 300d, 152k

ya. dry rusty linkage is a bad thing. MB recommends disassembling and cleaning out with penetrating oil such as wd40, then lubing all sockets with atf.
another thing that will cause stuck accelerator is the heater hose that crosses over the oil filter housing. it's common practice to move the hose out of the way when changing glow plugs, and if it's not moved back, the accelerator will stick on the hose, causing the same symptoms.
so... if your mechanic just changed or inspected the glow plugs, it's possible this occured!

Been there done that!!!!
http://www.peachparts.com/shopforum/showthread.php?t=255806&highlight=linkage

Just bought an 82 300SD, and I've been reading a LOT. I think lubing my linkage is tomorrows to-do item. My cruise is really jumpy, and the pedal feels stiff. I had assumed it was the cruise amp as well, and that the pedal just feels that way. The car has been sitting for about a year, and if a little lube fixes it, I'll be really happy. Plus, its better than having the pedal stick and plunging over a cliff Wile E Coyote style... :D

Thanks for the heads up!

lubing the linkage is a good idea, but stiff pedal is usually the guide and bushing on the valve cover.

Well the linkage and all are getting the good once over, and if I'm lucky it'll cure my cruise control. If I'm not, I'm no worse off than I was.

Well, a month down the road after cleaning and re-greasing with lithium grease. The pedal feels a lot better - its still stiffer than I'm used to, but there's a lot of linkage to push and pull, so that follows. My cruise is a lot more steady when it works, but it does just cut out sometimes, so I think I have some amplifier or grounding issues as well. Still, an improvement. An item to check if you buy a car thats been on the deferred maintenance plan.

Using the brake pedal would have definitely slowed down the car if such an event did occur. ;)

Where is your sense of adventure?:D You could always do like the guy from California that claimed he had a runaway Prius. Rather than turn off the key or hit the brakes, he wanted others to believe he reached down and pulled up on the accelerator while traveling at nearly 100mph!:eek::rolleyes:

Just kidding! Yes checking/lubing linkages after any underhood work is definitely a great idea and often overlooked.

... or putting the gear into neutral, or turning the ignition off..

Maybe this problem is just because he never floor it? Everything that is not being used will stop working eventually.

Open the amp, and resolder the bigger welds. They get hot when the cruise is working, and when they do, they lose connection.

Yeah, that's my plan, but its low on my priority list right at the moment. There are no major problems with the car but all sorts of minor ones. I think I'm going to rebuild the main power cables and engine ground etc, just to eliminate that from consideration for all the electrical gremlins.