rough engine

[welshpe]

My 1967 230SL starts fine and idols fine but won't get over 1200RPM until it warms up and then it still bogs down badly between 1200 and 1800 RPMs. Once over 1800 it runs well. Maybe some slight backfiring but more of a miss. Any ideas?

[J. Huber]

Are you still using points? If so, I'd check the dwell angle to be sure you are around 38-40 and/or replace them and maybe put some new NGK BP5ES plugs in.

[ja17]

Hello welshpe,

I would go through "the linkage tour" first.  It makes a big difference it the linkage is set up wrong.

[welshpe]

It was sticking points!!! Just a touch of grease and it's running great.

[peller]

I have the opposite problem with my '68. When giving it the gas, the engine runs smoothly. However the idle is rough, with the car on the verge of stalling. Its idling at about 500 rpm. How do I advance the idle up a little bit? I think it needs just a smidge.

[ja17]

Try the big slotted air screw on the intake manifold first. coun ter-clockwise should increase the idle. If the engine does not respond,  we will need to make other adjustments.

[peller]

Can you post a picture of the screw you are referring to?  I want to be sure I am looking at the right one.

Thanks

[Jonny B]

Here is a photo of the idle air adjustment screw that Joe A is typing about, from my 1970 280 SL.

[peller]

Awesome Guys! I'll give it a try tonight!

[Benz Dr.]

It was sticking points!!! Just a touch of grease and it's running great.

It's very important to have a bit of grease on the cam lobes. Bosch makes a special grease which is very sticky so won't fly off and contaminate the points. I use it on all of the moving parts that can't be oiled after assembly. A tube of this stuff will last a life time and you will have plenty left over. I've had the same tube for the past ten years and it's only a 1/4 used up. And I use it a lot.

I've seen where the points would flutter on a freshly rebuilt unit. When I added a bit of grease they settled down and worked perfectly. A tube is only 5 or 6 dollars. 

[J. Huber]

Hey Dan, any trick to applying this grease to the lobes?

[peller]

Try the big slotted air screw on the intake manifold first. coun ter-clockwise should increase the idle. If the engine does not respond,  we will need to make other adjustments.

Joe and Johnny,
 Finally got around to working on the car this weekend. Adjusting the air screw did the trick and she's idling like a top now.  THANK YOU for the help!