Full RPM shift points, early upshift, rough idle, vacuum tuning etc

[Bondavi]

UPDATE 6/1: I have ordered a new fuel pump relay for this, euro spec with the 5950 rpm cutoff. Lets see if that solves this. I also found out my idle controller module IS BAD. So looking for a correct one for a euro 500. ANyone have one? 002-545-07-32?

Ok I admit, my car's kickdown solenoid is screwed. I need to get the car up on the ramps and fix that. Hence I've only been on 2nd gear starts from day one. Not that I'm complaining, the car really does MOVE, even starting in 2nd.

My question is, flooring the pedal from 2nd to 3rd, I get upshift around 4700-5000 rpm, I can't say if I triggered the kickdown switch at that time, but the pedal was pretty floored but I've only done this one or twice. The cops around here are pretty stringent, and this 500SL would be doing autobahn speeds if I wanted to do a "simple WOT test for 2nd to 3rd." Its that quick!

Basically my question here is, if there is a vacuum leak somewhere in the system it will result in early upshifts, right?

I'm still figuring out the vacuum tubing from factory along with the USA DOT federalization diagrams put on the car. I pulled the vacuum lines at idle (which is on the rough side, didnt do that before when I redid the chain, pulled off the "piggyback quick fix" vacuum lines, and manifold). Heck, the EGR valve and charcoal canister were off the same line! So trying to stay factory correct I refurbished all lines (except at the firewall coupler set, will get to that later). I feel vacuum coming out from the lines supposedly for "EGR" from the throttle body switch and the charcoal canister off of the upper intake manifold, even at idle.

Chances are the CIS mixture was leaned out due to the vacuum leak I found before replacing the TB/timing chain/manifold gaskets/all injectors/seals, etc, so maybe tuning the mixture will smooth out the rough idle, you think? The car does pull real hard, aside from a slight vibration, maybe spark plug wiring?

A lot to consider here, but I want to get the vacuum done right with the new bushings and plastic lines I have in place. Pics from 500SL owners would be great to use as reference.

Tomorrow I will run the car and disconnect certain vacuum lines and see if I can find a smoother idle.

Say, where can I source a new harness for the warm up regulator/thermoswitches/idle controller stuff?

[kbannister]

You're right, a lot to consider. I wouldn't worry about the kick down speed until you get the idle right. Sounds like maybe you disconnected or broke a line during the chain replacement. You said you have vacume at the egr at idle, maybe that is the idle problem. Be sure the egr is working properly before going on to other causes. A malfunctioning egr will cause a rough idle and smooth out under acceleration.

Not sure if I understood your 2nd gear start statement but these cars are 2nd gear start. And you are right, autobahn speeds are running when it does shift.

[kbannister]

Okay, I had to go to the hardware store and didn't see any POOOLICE on the way there so on the way back, I let it have it. Shift point from 2nd to 3rd is 6000 rpm. Did it twice at two red lights and same shift. Don't know what it is from 3rd to 4th, and sorry, I ain't gonna find out, at least not this weekend. Actually I would assume it is the same.

[TheV12pwr]

Originally Posted by kbannister

Okay, I had to go to the hardware store and didn't see any POOOLICE on the way there so on the way back, I let it have it. Shift point from 2nd to 3rd is 6000 rpm. Did it twice at two red lights and same shift. Don't know what it is from 3rd to 4th, and sorry, I ain't gonna find out, at least not this weekend. Actually I would assume it is the same.

...one day you'll make 'the news'

[Bondavi]

I pulled the EGR vacuum tube off and plugged the vacuum tube with a screw. Idle smoothed out, but rather than getting 750rpm idle, it stays at 1500. Pretty sure my warm up controller PCB is fine, will have to go through the vacuum line routing again and recheck. No one seems to have an asnwer about vacuum routing. My federalization papers show the EGR valve getting its vacuum off of the tube opening in front of the idle controller valve. But the throttle body vacuum switch diagram shows an opening that is labeled "EGR" so I plugged that directly. Was still getting vacuum at low idle, hence EGR was open at idle causing the rough idle.

Maybe I should just plug off the throttle body EGR vacuum opening, and lead the line from the idle controller unit into the EGR?

If only I had someone else with a 500SL near Sacramento I could compare the vacuum routing and get mine set up right. Hmm...