1994 E320 starts surging after reaching normal operating temperature - PeachParts Mercedes-Benz Forum

dablk1 · #1 06-15-2010, 11:31 AM

It starts fine and drives excellent. The surging only occurs after it reaches normal operating temperature. Any suggestions?

deanyel · #2 06-15-2010, 11:41 AM

Surging = read the fault codes on the 16 pin connector.

dablk1 · #3 06-15-2010, 12:11 PM

I haven't had much experience with these engines. How do I read the fault codes?

babymog · #4 06-15-2010, 01:11 PM

try a search for "arthur dalton" and "code reader" and it should return threads with the codes and instructions for building a simple reader (LED, switch, resistor, box).

If you have no CEL/Check Engine Light, and it does come on with the bulb-test when you start your car, the most likely culprits are: vacuum leak (fitting under the forward half of the intake), O2 sensor out of range. Sounds like your car is running lean.

Kestas · #5 06-15-2010, 01:12 PM

http://www.peachparts.com/shopforum/showthread.php?t=107630

mlozzi200478 · #6 06-16-2010, 01:30 AM

sounds like it may be a faulty idle control valve under the air box cleaner,its a big round aluminum valve with 2 black rubber pipes going out of it,or could be a bad o2 sensor.remove the idle control valve clean itout with carb cleaner,also spray carb cleaner down the air sensor plate under the air box.this may help if there is a build up of carbon,also run a bottle of lucas fuel injector cleaner,i have good results from it.

Kestas · #7 06-16-2010, 09:23 AM

The throttle bodies of these models suffer from disintegrating wiring insulation, same as the engine wiring harness. Are both original?

dablk1 · #8 06-16-2010, 09:53 AM

I'm pretty certain that they are original. The owner recently aquired the vehicle after it sat for a couple of years. I've been pretty much working on my 91 2.5. I have very limited knowledge about the E320's. I'm not even sure where the ICV is located or where to start with the wiring harness.

Kestas · #9 06-16-2010, 10:17 AM

Next time you're under the hood, pull back some of the armor on the wiring harness and take a look at the wiring insulation. You'll have an appreciation for why the original wiring needs to be replaced. The cost is about $1100 for the part. Many mechanics refuse to work on driveability problems unless the engine wiring harness is replaced. The same can also apply to the electronic throttle assembly (ETA), which is the official name for the idle control valve. It is located by the plastic intake.

dablk1 · #10 06-16-2010, 10:31 AM

Ok, thanks. I want to make sure that I am clear on the location of the ETA. Is below the air filter housing or just beside the plastic intake.? If I'm not able to get under there today it will definitely be tomorrow.

Kestas · #11 06-16-2010, 12:54 PM

This picture should help. Follow the air intake from the air filter, over the valve cover, and to the intake manifold area. Where the large tube stops is where the ETA is located (arrow). It's not visible in the picture.

dablk1 · #12 06-16-2010, 01:13 PM

thanks again...I'll check it out and report back.

dablk1 · #13 06-22-2010, 08:48 AM

Ok I followed the tube. I beleive that I located the ICV/ETA. How do I remove it? There was some insulation that wouldn't budge with 2 clamps attached to it.

Kestas · #14 06-22-2010, 08:57 AM

I had to remove the upper intake assembly to get at the ETA. Some reported removing it with the upper intake in place. I'm not sure what you mean about the insulation and two clamps.

dablk1 · #15 06-22-2010, 09:10 AM

Well I removed the upper intake and I had to loosen an upper clamp above what I believe to be the ICV/ETA. The clamp was attached to what appeared to be rubber or foam insulation. There is a second clamp(lower) that I also loosened. This is right above the throttle assembly.