1998 E300 Intermittent No Power from Stoplight - PeachParts Mercedes-Benz Forum

RLGDiesel · #1 10-23-2013, 02:07 AM

Hi all,

Latest problem...I recently changed oil and filter, and I replaced my warped air filter box at the same time (heat from turbo = wavy plastic = loose clamps). I transferred over the MAF to the new airbox and everything seemed OK.

Over the last couple days (about 10% of the time) when I hit the accelerator from a stop, I experience a 1-2 second lag before any response from the car. It's not like a transmission slip sensation when the RPMs increase and then the car lurches forward. Instead, nothing happens for the first moment I touch the gas pedal...then all of a sudden the car wakes up and it's business as usual. There is a dead spot in the pedal and I'm not sure if it's caused by fuel starvation, electronic faults, or other gremlins. The throttle position sender is $500 and the MAF is $300, so I don't want to start throwing parts at this problem. No check engine lights or pending codes by the way. Throttle cable slack seems appropriate...moves gradually just as a helper actuates the pedal. I know these MAFs are delicate. Could moving it to the new airbox jostled it enough to kill it? The vacuum hoses near the air filter still look undisturbed. I'm really lost and annoyed by this one!

Here's a thread of someone with the EXACT same problem...no solution ever reported by original poster.

http://www.peachparts.com/shopforum/diesel-discussion/207503-e300td-hesitation.html

Other info if helpful...fuel filter, plastic fuel lines about 10-30K miles old. Fuel tank strainer original. Air filter brand new. Diesel purge 10K miles ago. Transmission fluid 20K miles ago.

jay_bob · #2 10-23-2013, 06:22 AM

The flow is your foot -> pedal -> cable -> sensor -> controller (in the big black box on right rear side of engine compartment) -> actuator (on false firewall on right rear just above the turbo) -> another cable (that wraps around the back of the engine) -> IP rack.

Rube Goldberg comes to mind.

As you can see there are several links in this chain.

Unfortunately you cannot see the motion of the actuator to rack cable easily, to determine if it is moving as it should.

I am waiting for the day when M-B finally decides to post the service info on the 210s the same as they have for the earlier models. It is very frustrating trying to work on these cars without the documentation.

As it says in the referenced thread, I would check the connector at the accelerator sensor and see how the voltage changes as you push down.

Failing that you may have to drop by your local dealer (or Indy with a Star DAS system) and see if they can pull the detailed codes you can't get via OBDII. OBDII is just the government mandated minimum for emissions controls, for the "rest of the story" you need to hook up a Star DAS system.

RLGDiesel · #3 10-23-2013, 12:59 PM

Great tips...I did not realize there were so many links in that chain.

Re: The controller (in the big black box on right rear side of engine compartment). Is that in the same black plastic box as the transmission control module...the one that has the stickers on it like "Battery Under Rear Seat"?

Re: The actuator (on false firewall on right rear just above the turbo). What is the false firewall? Any way you could circle it on a picture or something. I didn't see anything that resembled an actuator on the firewall but I might be missing it.

Do you think I messed something up when I removed and installed the airbox or is this a coincidence?

Thanks again!!

TMAllison · #4 10-23-2013, 01:21 PM

If it worked well before I would suggest backtracking and reviewing the work you performed first. Air leaks in duct work, etc.

Might want to check and make sure you reconnected the vacuum lines at the transducer down and below the MAF/Air filter box. Controls the turbo waste gate.

RLGDiesel · #5 10-24-2013, 08:47 AM

Thanks Terry. I checked the rubber boot from the MAF to the turbo for any cracks or leaks with a flashlight. I also looked to be sure all lines were attached to the vacuum transducer since I had to move that entire assembly to the new box.

I initially thought vacuum leak but ruled it out since the car runs awesome once it takes off. No rough or surging idle at all. Could a vac leak cause a delay off the line like I'm experiencing or does it sound more electronic to you?

RLGDiesel · #6 09-17-2014, 06:57 PM

Update to this: I replaced all 6 vacuum lines between the transducer, wastegate, and other attachments and problem solved. There are 3 vacuum lines per transducer. I also switched the transducers from side to side to rule out an electronic fault. Hope this helps anyone in the future.

shertex · #7 09-17-2014, 08:22 PM

Quote:

Originally Posted by jay_bob

I am waiting for the day when M-B finally decides to post the service info on the 210s the same as they have for the earlier models. It is very frustrating trying to work on these cars without the documentation.

Jay, would a WIS subscription meet this need? Or is that not enough? I've been pondering the same thing myself.