I have a neighbor who owns an 86 mercedes 260 SL. He's had it into the shop
several times, due to an intermittent problem. Sporatically, he experiences
a loss of power, and the vehicle will not go above 30mph. Just as
mysteriously as it happens, a few miles later, it clears up and drives as
if nothing is wrong.
When he started the engine for me, I noticed that the RPMs rose about 300,
then dropped back to idle again. The idle change wasn't like a rise and fall
from bad carburetion, but was more like the rise an engine, compensating for
an air conditioner switching on, would be.
Does anyone know the problem, or has anyone had this problem that could give
me some advice?