Greetings! I've been looking for a site like this one, now maybe I can get some answers.
I have a 1995 C280 (it's green, does that make a difference?

) that has had an odd problem for quite a while now, and it may be progressing. Here's the situation.
There are a number of places around where I live where there is a rather long slight downhill that leads to a right torn and then acceleration, most notably the freeway on-ramp not too far from home. If I cruise down this hill, ease into the turn and accelerate the car will start to shake, cough and sputter, and I must pull over, turn off the ignition, then start it up again to clear the problem. After that it runs fine. My service center (not MB dealer) replaced the engine harness, and then the fuel sending unit in the tank (the car is on its second tank, third or fourth sending unit). The problem cleared up for a while after replacing the unit in the tank, but it's been back now for a while.
Recently (last two months) I've had an idle issue. When idling, the engine will miss, not a constant miss, but every few seconds (not regular) it feels almost like putting it into drive from neutral. I don't notice the tach changing, although if the roughness comes close enough together the tach will move slightly). The car runs fine once I get beyond idle.
I don't know if the second problem is an offshoot of the first. A search of this forum points towards the OVP, although the reference I found indicates it's behind the battery by the firewall, but my battery is in the trunk. Where do I find this OVP and how do I test it? I looked for one on this site parts catalog but didn't find it.
advTHANKSance...
Cecil...