Need Help, Idle Control Valve and Filter Prob..
 

Dear All,

My w124 is already 13 yrs old this year, and of late my idling has been bad... its fluctuates badly from 500 to 1.5 rpm ....

i have a few suspects, the fuel pump and some sensors, cannot be the ECU cos its new and recently upgraded with Powerchip...

can you guys help me with the sensos such as 02 / lambda sensor or air mass index sensor?

can u indicate how many sensors must i replace ?

Start by cleaning the idle control valve...
 

Do a search under "idle control valve".

yo.. thanks man..

did a search, seem like the primary culprit could be the idle control valve and its connecting hoses..

really hope its not as bad as some of the search results i was going through...

frankly i did not know w124s or Merz has such a serious and common problem... erm....

will update so see if i can sort this problem.... *sigh :o

Having had the same problem (idle fluctuating between 500 and 1500) on my 1986 300E, having read all the same threads you're reading, and then having fixed the problem by reconnecting a vacuum line that came loose from the intake manifold, I reached the following general conclusion. It appears to me from the many different threads with the same initial symptom but different resolutions, that the fluctuation is a very general, catch-all symptom. It seems like the fluctuation is just the natural behavior of the fuel injection system hunting for the right mix in a system that has some flaw that keeps the mix from ever being right. Having noted that there were many *possible* things that could foul up the mix, I looked for the easiest, cheapest one, ergo, my vacuum leak. I hope your luck is similar. Mine was aided a bit by the recollection that the problem started after I'd done some other work, so I started looking for loose hoses in that vicinity.

where is the idle control valve?

can't seem to find it after i pop opened the hood.... :(

i also notice kinda major oil leak from the engine oil to the air filter? why is this happening... *sigh...

some more additional pictures... idling is a rough ride.. with probability of going dead / stall at the traffic lights....

think i need to service the idle control valve and all its connecting piping... what da' u think? :confused:

check the potentiometer.
 

Netken, please, after you clean the idle valve and check de O2

sensor, have to chech the Pot. The voltage between pin 2 a

ground has to be 700 mili volts or .7 volts, engine running. If It

doesn't match this value, trie to get it rotating POT right side a

little bit down or up direction. For do that, may be, you have to

disconnect the Pressure Regulator to get access to the POT cap

and 4 screws. The two left screw, under the cap, are using as

pivot t, losse 4 screw only little bit. Conect the Pressure

regulator, star the engine, instal the Multi voltimeter red at Pin 2

and Black to batteri ground. Take initial voltage readings

between Pin 2 an ground. If its different than 700 Mili

volts, then rotate Pot right side very slowly, few degrees, lucking

for to match 700 Milivots, +/- .250mv. You will notice the change

of RPM when you rotate the Pot a little bit.

iF YOU dont match .7 volts, after ROTATING THE POT, may be

you have to graduate the tiny screw on the front of the Trim Pot.

Read the Chris Marteen, Jay 300, Sbourg, Threadid and others on

06-25-2003. and "AIR FLOW METER POT SOURCE - BOSCH CIS"

ON 05-25-2003.


Good Luck.

Mario farias
laprefar@cantv.net

RE; IDLE
 

My car was oscillating at idle quite a bit, I pushed on a clear vacumn hose on the air intake and it has never done it since.

1995 E320

i will be bringing the car to the service center tomorrow.... so many things to repair and service.. will update later.. cheers! :)

IT IS HERE (see circle), HELD IN BY A BUSHING RESTING BETWEEN THE MANIFOD PORTS.

Hi! I got 87 MB 190E 2.3L. Basically, I had the same problem before, engine oil on air filter housing. Stall (after warm up).

Now, I changed valve stem seal, idle control valve, fuel pressure regulator and OVP. Problem seem gone.

Hope that can help you out.

well, after going to the mechanic, i changed the valve stem seal only... the problem is still there but not as bad as before.... :)