Ok my car has a problem with idling. When the car is in PARK it will run at around 750rpm then jump to 2000 and hang for a minute and then back down to 750. When in DRIVE it hovers around 500 or 600 and is on the verge of dying. Sometimes it will die sometimes it won't. I drove it to tafel motors and they looked at it and determined it had a bad vacuum leak. Later in the day the said the total to fix would be $1400.00. They said that not only is there a vacuum leak but the Air flow housing is bad. The mechanic said the sensor is not giving a correct reading. The part is 800, although I found it on benzbin for 550. He said that should clear the problem up. Does that sound about right??? Also now the car won't run hardly at all though. I not sure if putting the new vacuum lines on did something. It was the vacuum lines right by the air flow housing.

What do you guys think?

Thanks

Come on guys...anything???? Thanks

Jimmy

When my 2.6 started misbehaving at idle I found that the idle signal switch on the throttle body was not functioning properly, but fixed it with a few shots of WD-40 and it's been fine ever since. I also checked the microswitch on the linkage and it was okay.

Chances are your problem is something simple. Unless the engine is exhibiting bad behavior at other than idle, I doubt of the airflow/fuel meter needs to be replaced.

These cars have a fairly complicated idle stabilization system, so if they misbehave only at idle, this system should be checked - sensors, wiring/connectors and idle air control valve.

Others have reported solving idle problems by replacing the airflow sensor switch on the fuel meter. According the the KE documentation I have this potentiometer is only used while the engine is warming up. Go figure!

I think you need a second opinion.

Duke

We will know friday hopefully. My brother in law is sending me a used but working air flow housing with the fuel distributer as well for FREE!!! The guy at tafel said he test the sensor on the air flow housing and said he was sure it was bad. If that doesn't fix it I will tow it home and do somethings myself. Thanks for the help Duke

It could also be the airflow potentiometer.
Do a search on it. There must be at least 10 very looooong posts, with pictures and detailed explanations of all repairs.
Good luck.

__________________
1999 Porsche 996 Carrera Convertible
1994 420E - SOLD
1986 300E - SOLD, what a car
609 Certified

hey guys,
i did a ton of searches and come up with several good threads. Correct me if I am wrong but isn't the airflow potentiometer the sensor thats on the air flow housing, the on Mercedes says you can't buy by itself? I think a few people have posted bosch part numbers if thats what you are referring to.

Thanks

Well guys the airflow housing and fuel distributer was replaced with a used working one that had been wrecked in the rear. It seemed to help but still has a idle problem. I can drive once it warms up and it doesn't seem to flucuate much. I noticed that when it's cold it seems to jump up to 1500 rpm and then back down to 500 or 600 sometimes it will die. Also if I give it gas and hold the rpms to say 1500 it will stay for 30 seconds and then just drop down like I wasn't even pushing in the accelator. I cleaned the idle control valve but that seem to help for only about 3 minutes and then back to the same old $hit.

after some more testing I made sure the idle air control valve was getting 12 volts and it was. I then unplugged the connecter and it didn't do anything, no change in idle. Weird thing is it seems to not surge in idle anymore. It stays around 600-700 no more 500-1500 crap. It does run rough though when it's cold, soon as it warms up it seems to idle pretty good. I am finally making some progress and soon enough hopefully I will have a smooth idle!!!!!

Thanks guys

Well I got a used but working OVP and also idle control valve installed them both and still no change. I installed the ICV first. Started the car and it seem to idle pretty good till I revved the car up then it hanged at 1500 then down to 500 and back up. Same ol stuff! I then popped the OVP in and had no change at all. One thing I have been noticing with the idle is the economy gauge stays about mid way when it's surging. Also when I barely apply the gas it goes all the way in the red. Doesn't seem right. I don't think it's the a vacuum leak because of how erratic it is. It will surging for a minute or two then stop. It might start again though at anytime, also when it's idling decent if I rev it up to about 2000-2500 it will usually hang on the way back down at 1500 and then surging a couple times.

Bad thing is it seems any fuel problem seems to cause a surging idle after reading these forums.

Can any of you guys that are experts on idling maybe do a step by step on the steps to remedy a problem like this as well as the correct values the sensors should spit on the voltmeter.

Also anyone know where I can get a 88300e service manual on cd at??

I read you replaced the Idle Control Valve with an used one.
Have you tried to clean it?
I was experiencing the same problem, after cleaning the ICV the problem never came back.
Lots of carb cleaner, and then some WD-40 for lubrication.

__________________
1999 Porsche 996 Carrera Convertible
1994 420E - SOLD
1986 300E - SOLD, what a car
609 Certified

I tried cleaning cleaning the ICV that was on the car. I did not try and clean the new/used one. I will take it off and try to clean it as well and see what happens.

Little update not sure if this matters or not. I was messing with the car again Saturday and as the idle was fluctuating between 600-1500 I unplug the sensor on the side of the air flow housing it the fluctuating idle stopped the same was as when I unplugged the idle control valve. I am starting to thing that something that tell these things what to do may be bad. I also replaced the OVP and that did not help at all.

Maybe someone could reply with a step by step for tracking this down and I will try that. Letting the dealer look at it already cost 475 bucks and it's pretty much still the same. Plus the car is pretty easy to work on, I am just not familiar with what readings I should expect.

Thanks

Jimmy

Also a 1988 300e cd would be nice, if anyone knows where I can find one.

Any update on this issue? Did you get it fixed? what was the solution?

I am also interested to hearing if anyone have solved the surging problem. My car does the same thing as discribed by djimmy31.
My solution so far is to drive with the ICV disconnected.

Hurshi

__________________
1989 230E, 8v, 166.000 km, updated to 94/95 trunk & hood
2002 Daewoo Nexia 50.000 km
Sold:
1987 VW Jetta GLE 16V, Recaro seats
1982 Volvo 240 DL (lovely car!)
and few more american cars.

Well,

I've replaced the ovp "used one", air flow housing "used one", new fuel injectors, and finally had shop adjust co mixture. Car now idles fairly well and has ton and tons more power. On occasion though like new years eve night upon coming to a stop sometimes it would either idle real low like 350 -500 or just die. Starts right back and runs fine for awhile. I am thinking about putting a new idle control valve on it.

The 300e needs a website devoted to idle issues!! lol