erratic idle and running rich... massive vacuum leak?
We have a 300 that has a bipolar disorder. It either runs great or it idles high, low and
dies and it is running rich - like 10 mpg rich... I replaced the air idle valve and it was better
for a while but never perfect and now is up to its old tricks. I also bought new hoses for
the connections to manifold and engine but have yet to put the engine side one because
the engine side is buried. If you accelerated down a off ramp - 9 times out of 10 it runs so
rich you,d swear you were driving a hopped up diesel. Also is there a large rubber gasket
in the intake that is prone to cracking. Thanks.
sounds like a fuel pressure regulator
Search Mercedes-Benz 300-Class Questions
Mercedes-Benz 300-Class Experts