380SL Rough idle unidentified wire and vacuum hoses
Being he nice bother that I am, I graciously offered to help my brother with his 1984 380SL. One of his timing guides broke, his chain jumped a link and you know the rest of the story.
I’ve worked on many American and Jap cars before, but this is my first time tearing into a Mercedes. During my spare time and a few months later, I now know why the shop wanted 4-6K for the job.
I labeled most of the wires but was unable to take pics at the time I was tearing it apart. I found a wire and vacuum diagram at the library, but it does not illustrate the parts I’m searching for.
Once I got it all back together, it did start up only after a few quick cranks, however, it is running very rough and will not idle. I adjusted the timing and little improvement. During reassembly, I replaced all belt and hoses including vacuum hoses and fittings. I believe I got the valve timing correct during reassembly. I’ve disconnected the Idle Speed Adjuster (electrical connection) and this made no difference. The adjuster appears to be in working order, as the valve opens and closes. My brother said it ran great the day before the vales smashed. It’s been sitting about 7-8 months. Today I’m draining the tank, checking the fuel filter and will try some premium gas with fuel cleaner.
I do have a few questions regarding some wires and hoses I’m uncertain about and hoping someone can help with. I’m not sure if they are related on not but here goes:
I’m rather certain I got all the wire connections correct with once exception. On the top right side coming form the main wire harness, there is a single orange wire with an eye and bold connection. I have no Idea where this goes. Any ideas? See attached pic.
As I mentioned, I found an emissions diagram for the vehicle, so I’m certain most of the hoses are correctly hooked up. However, there are a few not illustrated:
There appears to be a fitting coming from the top of the Warm Up Compensator. The white hoses on the side are hooked up and in my diagram, but here is what appears to be a hose connection on the top. I ran this to what I believe is the ‘Kick Down’ switch located the right wheel well next to the radiator filler bottle. Can anyone confirm these two hook together?
One additional hose I’m uncertain about is one that runs from a tee located toward the back bottom of the fuel distributor. One end hooks into some sort of valve that has fuel hoses running into the distributor. The other end I ran into the breather tube from the valve cover.
I’ve attached some pics. Hope someone can point me in the right direction of give some useful suggestions on what to try, or if anyone knows of a reliable Mercedes Mechanic in the Las Vegas area, I’m getting close to taking it in.
Thanks in advance.
Update - later that day....
I drained the, checked the filter and all looked good. I put in some premium with some fuel cleaner.
I read a post earlier that talking about cleaning the Idle Speed Adjuster with some carb cleaner. I did that and when I disconnected, idle did increase, but still no power.
For grins, I connected the orange wire to ground and that did something! It activated an electric valve hooked into the fuel distributor mounted horizontally on the left side. Not sure what it is, but it did wonders.
Question, is this suppose to be hooked to ground, or is there a particular place?
Thanks again - by the way, great fourm.
Last edited by cjmarinch; 05-29-2008 at 11:38 PM.