Find where the idle adjustment cable attaches to the throttle linkage on top of the engine. It screws in to the linkage, if you turn it counterclockwise you can raise the idle and clockwise you can lower the idle. On my car even at full counterclockwise it was still idling too low, which leaves the cruise control adjustment as a secondary. The cruise control cable also screws into the throttle linkage with a plastic threaded thing. Turn it counterclockwise to put tension on the cable and raise the idle.

 

Aha... the cruise control... that might explain a lot... My car is missing the cruise control cable... I have an empty hole. Seems to be that the other cruise control components are in place, cruise control amp is under the driver's kick panel... Any idea where I can find the parts and bushing? Idle adjust turned fully counterclockwise is also still not fast enough. Hence the zip-tie rig on the linkage to hold the idle at 750.

 

That is not the right way to adjust idle, you want to leave the linkages set to the FSM guide lines. The adjuster is on the side of the ip, below is a picture of one on a 300D...

Becareful as the lock nut can be frozen on and I have seen people break off the mount point..

The bolt also has a spring loaded pin at the bottom of it, I have read of people who have had this spring stick and thus the idle can have issues..

Also here is the PDF describing how to...
http://mb.bolinko.org/wis/w123/CD02/Engine/615/07-100.pdf

 

Hmmm.... I was wondering where that was. I even turned up the IP fueling (internally) thinking that would help - ended up backing it off because I was getting black smoke (too much fuel)

I'm going to pop outside and have a look at mine.

 

Sorry about the pictures...

So I went and looked at that area on my IP... uhh...... ?????????? :crying

 

Well, at least your not the one who broke it

Looks like you'll need that zip tie again and need to hunt for a replacement...

 

Well that's true. Maybe this is part of the reason PO thought the engine was "blown" I knew something was supposed to be there but wasn't sure what. I have a spare IP attached to an engine in storage, but that engine is from a '78 Automatic... I think they used a different IP? Either way it's 60 miles away... But, for now I can live with a zip tie and a pair of scissors in the car in case of an emergency.

Idling that low @479RPM there is one hell of a piston slap that could easily be mistaken for a rod knock. Not to mention it chugs smoke before dying.

 

Very good possibility...

If your is a stick shift, the ip will be fine....The 78's don't have the gizmo's on the ip to control the egr's/alda/auto trans stuff and I don't think you can move them over from a 82 to a 78 injection pump....if you have non of that, you'll be good..

Just installing an ip and timing it is a PITA and very difficult if you've never done it before.....Once you get the hang, its like changing the battery....ask how i know lol

 

Yep, manual transmission & I (as of yesterday) removed the EGR linkages & butterfly. Still a few other components to remove, (any chance there's a list of components to pull?) but the engine seems to have a little more pep. I also have the "jake brake" sound back... absolutely orgasmic.

When downshifting.... oh it is absolutely hilarious.... and a bit cruel at the same time because it scares pedestrians....

And damn are valve adjustments going to be easier now that I don't have to futz with all that linkage.

Would be interested in knowing your IP story

 

Can't really give a list but here's a diagram..

Oh I know all to well on the scaring pedestrians with my shifting thing

Just wait until you start having all the monster trucks wanting to race you as they get pee'd that your sedan sounds louder then their 90k pos ford truck

I got pulled over by a cop in Berkeley once, as the car was screaming and she thought I was speeding in a school zone....going down hill...using the clutch to keep the speed down frightens all lol One day I will buy a new hood pad and maybe that might help...

I bought my 78, with the ip removed because it was "bad" turned out it was an ex veggie car....and I had to learn in a how to time/install an ip...I didn't know that a pre 80 ip would work and the egr/vacuum crap can be removed...I travel way down to find a 77....plus the car supposedly came with a good ip...that one was also gummed up....here's the thread.....man love that car, but boy she has been a pita....still needs so much, I need to steal someone's gold card lol And believe it or not, the cars only been on the road maybe 10 years...

http://www.benzworld.org/forums/w123-e-ce-d-cd-td/1632192-my-new-300d-plus-headache.html