Won't idle when hot

[Vetruck]

Update- Car has been smooth as glass for several days now. I would officially call this problem fixed. I cleared the code /service engine light a day ago and it has not returned in about 60 miles of driving.

[taz069]

I got ya beat by 5 days!! Not lmao!! But I did replace several needed items. All coils,and wires. Just waiting for my replacement tb ,purge valve,tb boot, and different ovp to come in now. Will split my wiring harness on my old tb this evening. And get it rebuilt for a spare. Yes mine has the same problems you have listed and thanks for the info on your writeup!! Check with chim in the classified he'sparting out his 96 c280 sport!! That be where my parts arecoming from. His was running and got t-boned. Thanks again!!

[mbsickness]

Seems like there are quite a few members with throttle body issues recently. For those folks who end up looking for a replacement make sure the part number match. There are a few different ones used over the years and in my case it had to come from a non-ASR C280 from 94-95.

[Vetruck]

Seems like there are quite a few members with throttle body issues recently. For those folks who end up looking for a replacement make sure the part number match. There are a few different ones used over the years and in my case it had to come from a non-ASR C280 from 94-95.

Since you mentioned it, I also thought it was very suspicious that several people are having the same issues all about the smae time frame (years wise). Kind of tells ya that everyone is going to have this issue from wires falling apart probably regardless of mileage, its probably more of an age in time rather than miles. Even a car just sitting there in a garage with low miles will suffer the same fate in the same time poeriod as a high milage car. Good ol Mecedes Biodegradable wires- the fuckers should have had a recall on this the filthy bastards

[taz069]

I am not so much sure on the year thing. I cut my tb wiring harness open last night and the thing looked brand new. If I can figure out how to send a pic with this new DNA phone I will.

[mbsickness]

In preparation of a rebuilt throttle body I removed the existing one from the car and just out of curiosity sliced open the wire harness. Didn't look too bad but it did have bits of insulation missing and cracks all over. Taz069 consider yourself lucky to have an intact harness. Is it possible yours was replaced in the past?

[taz069]

Mb I doubt it was replaced. Seeing the previous owners drove it into the dirt. Mine is looking like either a bad coil inside the tb or the potentiometer on the throttle linkage side.

[Vetruck]

Mine was just gone. I mean you could hardly see any isulation even attached to the wires, like about 10% still there and the rest of it feel out like sand. What amazes me is I know the previous owner of my car very well. He is an 80 year old guy that just babied this car and always garaged it. I doubt the car ever went over 70 mph. He also lives in Huntington beach about 3 niles off the coast were it is always about 10* cooler than inland here in So Cal- but yet not too close where things get corrosive on car paint etc like the ocean front homes do. This car lived in a perfect climate and was driven mildly- yet the wires were gone.

[mbsickness]

Hate to admit I was hoping for more damage as the car doesn't run beyond an idle. I hope the rewired throttle body does the trick.

[taz069]

Got the tb from chim in Friday and between rain downpours finally got it installed. After a few sputters things cleared right up running like a top again. I did disconnect the battery for 20-30 min after install. I guess the computer had to relearn things. All good now. No codes. Now onto the next lil noise. Sounding like the flex disc on the drive shaft right behind the tranny. It starts slow and as speed increases so does the sound. The sound is coming from around the shifter area. Yeah another problem. Thanks Ve for the write up.

[Vetruck]

Interesting it did the same few sputter at first. Thanks for confirming that. It is definately then the computer relearning on initial test drive. My sputters went away after 2 start and stops- and what I did get was very minor.

Good luck with the next project Taz.

Im actually heading out as we speak to get my tires mounted onto my wheels. Ill have pics soon. Not going on the car until later this week though. I have to fit the new studs and locktire and let them cure ont he car overnight maybe on Wednesday this week if all goes as scheduled.

[taz069]

Just had the car up on ramps. My flex disc's look great! Now the surrounding heat insulation is a different story. Did some rigging, hehe. A old coat hanger and built a arc to support the sagging padding. So far so good. I def would hate to have to replace that padding!!! Omg at the things to be removed. Car sputtered again just swapped out the purge valve and the ovp. Letting it sit with the battery disconnected and gonna put the charger to the battery. After I walk the pups and have a cold one. Looking forward to the pics!!

[Vetruck]

I ususally remove crap off the bottom of a car over time of ownership. things like heat sheilds and lastic guards etc. I like a car that is more simple and easy access to work on. Case in point I just shitcanned my plastic rear control arm covers. Heat shield can be done with dynamat if it gets hot int he cockpit. I have some of that laying around I use for heat wrapping parts like starters etc, or just plain l removing OEM heat stuff like you idsribe and stategically placing the new dynamat.

Just back from getting the new tires mounted
Attachment 1434

[taz069]

Car tagged and on the road and somewhat running smooth. It still has the intermittent stumble. Once it warms up it very rarely stumbles. Once in a while it does. Heading to AutoZone and going to have them put their scan tool on it. I have just about reached whits end. Now come to find out my front lower control arm rear bushings are on the way out. Not to mention getting some Lucas rear end gear oil for a change in rear end fluid today. Thinking about changing the fuel filter to see it this helps. I did put a new one on when I first got the car maybe some old residual crap in the tank has it partially blocked. Fingers crossed. After a year + I am starting to wonder if this lil project is worth it!!!!!!!

[Vetruck]

Give me more info. what rpm is it stumbling (ie- coming off idle, or none with steady throttle position...only when throttle position is changed? etc)

Is it the same exactly as it did prior to putting on Chim's TB?

[taz069]

It stumbles at around 2k with steady throttle. Now let me run this by ya. Just returned from AutoZone. Their code reader showed some new codes. 1 being p0325 and p0327 knock sensor. With this it could be low fuel pressure, defective sensor,wiring, or engine problems. Will check on all of this. Next is code p0441 evaporative emision system. Which could be loose fuel cap(not!!), evap canister or hose cracked, purge or vent solenoid defective, or vacum leak at engine(possible). And then we have code p0341 cam position sensor. It's new so I doubt that but one thing in their print out says cylinder misfire, check ignition system for bad plugs, wires, coils. Now I just replaced all of that. So possibly???? Hope this helps a lil Ve! Out to change the rear end fluid now with some Lucas 80-90w. Let me know.

[Vetruck]

Im not a real ECM/PCM guy at all, but I know enough about basics to make me real leary about the cam psition sensor has to be part of "when the injectors fire" and well as "when the ignition fires"

I do know and have experience with hall effect triggers (crank shaft triggers) that tell the ignition when to fire. I would greatly suspect the cam sensor is somewhat the same principle. and is a safer way to tell the engine if its safe to fire based on the condition of the timing chain.

[taz069]

Just found a old post in benzworld on this issue, back in 2010. It was in the amg section. The dude's wiring harness was fried where the plug meets the knock sensor. Mybe next weekend i can split and redo all said affected wiring if this is the case. Still have some parts in the works. I can say that my cam position sensor wiring is not of the best quality and that be from a electrician. With that said I'm going to look at redoing my harness from scratch. I do know of specific products where i can reuse the original wiring. Just put a different coating on it and seal it differently. And most of all reroute some of it. OMG!! But it can be done in a few days.

[Vetruck]

In my most getto fashion, I shall reiterate what fucking morons Mecedes-Benz executives are for allowing the use of cheap ass biodegradable wiring in the first place, and then what fucking low life money grubbing ass lickers they are for swindling there way under a the legal statue of limitation as to not issue a recall and simply send a message to all old Mecedes owners they give a rats ass about us.

FUCK YOU MERCEDES BENZ

[Vetruck]

and FUCK YOU STEVE CANNON



there, I feel better.

[taz069]

Lmfao!! Going to chime in a lil!! Ve to my understanding for this short term of dealing with this issue. That the knock sensors deal with fuel pressure applied to the rail system, and they deal with timing also. It's a computer vs computer . Say the cam position sensor is telling the computer I need +15 degrees(via throttle position, maf readings, intake temps) in timing advance , and the knock sensor is telling the computer I need a -17 degree in timing by way I'll adjust fuel pressure in the mean time. This is a totally new issue to me and still with the said problems we have these cars!! It would be best for me just to pull the old wiring harness and just rebuild it. Now that I have the car tagged and insured I no longer have the extra cash to throw at it. With that said I still have the front lower bushings to contend with. I just wish I could get my hands on the original owner and some mercedes engineers! And drag them behind my better than new c280!! Cause I have no degree (college) I have a will and determination to see this thru!! I dang sure should have kept my mouth shut now the rear bearings are gonna go out!! ROTFLMAO!!! Still beats a new car payment!!

[Vetruck]

Still beats a new car payment!!

Quote the fact- you got that right.

[taz069]

Be safe friend! Keep in mind that's why we were built!! We can do better than any engineering dept!! And heaven forbid if we had their design experience! Me for one do understand that the Mercedes factory took up American standards in 95-98. And hence pass the buck and used susubstandard material's (I.e it will break down outside of warrenty) recall issues could not have been adressed until well outside of a specific guideline. I still have my grandmothers 66 c-10 Chevy. And that booger shoot it some gas and it will run!! No cars or truck nowadays will last that long!

[bpeter]

Vetruck

Can you confirm if you rebuilt the wiring on the tb or replaced the entire tb unit.

[Vetruck]

Vetruck

Can you confirm if you rebuilt the wiring on the tb or replaced the entire tb unit.

I bought a brand new complete TB unit with the entire new wire harness attached all as one unit. It is a VDO unit. I have a 4 cylinder C220 and it was just shy of $600 shpped to my doorstep.