I have this 72 3.5, (US named 450SLC) and I am running rich, some books read for a adjustment to lean down under the dash on the passanger side against the firewall. The only device I found that may look like that is a alumium finned unit that has a turn dial on the bottom to the left of the unit in which you can turn clockwise or counter clockwise. Is this the unit for adjustment? If anyone knows please let me know. Thank You.

Tim

That knob is the fuel system mixture adjustment. About 20 clicks in the total range of adjustment. Count the clicks to remember the original setting so that you can go back to it if you turn it the wrong way!!

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Thank you, I thought that might be it. I have moisture and soot on start up only. I have turned 8 clicks so far, can't see a whole lot of difference. Is this 72 SLC 3.5 set up to lope on cold start up. The owner before me disconnected something he told me on the air cleaner intake housing to stop the lope, but I remember that some cars were set up to lope on cold start up so as to not have the cold start fast idle. I have not gotten my books or CD yet to figure this out.
Thank you for you help.
Tim
Woodstock, GA

So is this lope normal. I just brought home my new (new to me) '73 450 sl. The engine starts right up when cold. After a few seconds the engine begins to lope (rpms fluctuate up and down, up and down). After about 45 seconds, the idle smooths back out and all is well. Is this normal? If not, then what is the problem. Thanks in advance.

Joesixpack,
Yes, this is normal until you fix it, can be easily fixed.
1. Your computer control box on fire wall in passenger side.
2. Device located just to the left of and right beside the throttle value. This has to be replaced, very hard to get to and replace. I forget the name at this time. Its a sensor.
Replace device and then you should set you computer about 10 clicks to start. Adjust from there for running. You need any help, I am in Woodstock Georgia.
Call me 770-516-5307 - Tim

Thanks TSL. Is this an expensive fix? If you remember what this device is called I would appreciate it. I haven't had a chance to get the manual yet. Thanks again.

JoeSixPack,
It is not expensive, to do your self.
Bought part local. $60-90 I believe, going from memory, I am thinking it is the decel switch, cut have to check a few things.
Most of all be sure auto is in tune.
1. Go to computer on passenger side fire wall, remember how many clicks you go. Move knob all the way down or up and see if the engine responds to this. If so you computer is working.
2. Check the vacumn advance on distributor. Pull air line off on vacumn unit attached to dist. If engine responds to this then changes are your advance is working.
3. These two parts working, then switch decel switch beside the throttle body intake horn on manifold. You will then have to adjust your computer, maybe. Leave at setting that was hopefully made when decel switch was working.
This solved my problem quite well.
Best with your new auto. I am repairing and upgrading mine myself, learning all kinds of stuff about these vehicles.
Take a look at these products, have done excellent for my 72 SLC, I was getting 13-14 around town and I am now getting 16-17.
www.directhits.com
Tim