Mercedes-Benz Forums - My MB Online banner

1 - 9 of 9 Posts

·
Registered
Joined
·
23 Posts
Discussion Starter · #1 ·
As I posted on the other forum my car would idle really low to the point it would lag on acceleration when in gear and A/C on. I found the IACV unplugged and plugged it in. Now the idle barely goes down when in gear/A/C and it even shifts more smoothly :S. But once the car warms up when I go into Neutral or Park the Idle RPM's will gradually rise quite quickly, um to 4000 RPM. Until I go back in gear or turn the car off. I tried a spare ICV which was hanging around and same thing. Before all this though I had someone "adjust" the idle with an allen wrench in that hole (Don't know what it's officially called :() near the air intake under the air filter. Anyone have any idea at all what's wrong? Also once it's warm, in gear it idle's at 1000 and runs up to about 30-40MPH without pressing the gas. Help please :( And thanks in advance :)
 

·
Registered
Joined
·
1,561 Posts
you probably changed too many variables when you changed the idle screw thingy (i can't remember what it's called either) AND you plugged in the IACV.

Try letting it get warmed up, then adjust the screw again.
 

·
Registered
Joined
·
23 Posts
Discussion Starter · #3 ·
mgw_300e said:
you probably changed too many variables when you changed the idle screw thingy (i can't remember what it's called either) AND you plugged in the IACV.

Try letting it get warmed up, then adjust the screw again.
How would I find the perfect idle. Will I know when I get to it, 10,000RPM? I noticed it has like a balace effect? Too far and it'll die or too few, it'll die too. The increasing RPM isn't due to the ICV though? Thanks btw too. :)
 

·
Registered
Joined
·
23 Posts
Discussion Starter · #4 ·
I just took it to my mechanic and he said that the 91's 92's frequent that problem and it might be the wiring harness (i think that's what he called out). Omfg. -sigh-
 

·
Registered
Joined
·
1,561 Posts
JDW124 said:
I just took it to my mechanic and he said that the 91's 92's frequent that problem and it might be the wiring harness (i think that's what he called out). Omfg. -sigh-
the wiring harness issue is very obvious when it gets bad. all kinds of weird symptoms happen, but when you look at the wiring harness, it is literally crumbling before your eyes.

HOWEVER, the wiring harness was only an issue with the m104 engines. (maybe the m119 of similar MY? i can't remember)
 

·
Registered
Joined
·
23 Posts
Discussion Starter · #6 ·
mgw_300e said:
JDW124 said:
I just took it to my mechanic and he said that the 91's 92's frequent that problem and it might be the wiring harness (i think that's what he called out). Omfg. -sigh-
the wiring harness issue is very obvious when it gets bad. all kinds of weird symptoms happen, but when you look at the wiring harness, it is literally crumbling before your eyes.

HOWEVER, the wiring harness was only an issue with the m104 engines. (maybe the m119 of similar MY? i can't remember)
m104.phew. I'm gonna tell him that and see what he can figure out. Thanks matt for the help. I hope I get this issue resolved soon :D
 

·
Registered
Joined
·
1,561 Posts
phew is right - that wiring harness job can run $1500+
 
1 - 9 of 9 Posts
Top