I have an '81 240DL wagon. K injection, 140k miles. I love this baby, but it has developed a funky, intermittent problem.

It seems to be most prominent in 2nd gear (manual trans), also in 1st gear when you first get it rolling. Once or twice it has happend in 3rd gear.

Let's say you pull of a stop light, get it rolling in first, put the clutch in, shift to second, and give it the gas. It sounds like it is running on 2 cylinders, and bogs down. I have even spotted a little puff of black cloud when it does this.

After it bogs down, I Ease off the gas, put the clutch in, give it a rev, engage and ease it into gear, I can accelerate just fine, maybe a little sputter.

This started about a month ago, and does not happen all of the time. I have also noticed that idle speed seems a little high when it this occurs.

Distributor cap, rotor, and wires are all less than 9 mos old.

Timing belt is 6 mos old. timed it out when I replaced the belt.

Injectors and filter are about a year old.

I have a couple of ideas of what it could be, but I am hoping someone can help me put together a "short list" so I don't have to tear the whole thing apart trial and error. here are some items I have considered:

1)Leaking air bypass valve, that would explain the high idle.

2) I have dismissed play or wear in the distributor shaft, It's my experience that the distributor contacts tend to be nicked when this is a problem. Contacts look just fine.

3)incorrect air/fuel mix, misadjusted lift plate.

4)malfunctioning control pressure regulator

any advice anyone may have, or suggestions what might be wrong would be greatly appreciated.

Thanks,

Dan Sadoski