Rough start and idle fixed!!

[Nitrogenbalance]

I have read multiple posts this past month about rough idles, both consistant and non-consistant. I have also read a few posts on rough starts which was my main problem on my C43.

I went and bought a scan tool from sears for $149.00 and it works great. It also clears codes as well. So I plug the thing in and it tells me exactly what I expected. Two codes indicating fuel trim problems on both banks. The codes were P0**** on both I forget the exact codes.

So I purchased some NGK plugs #BKREY, and a set of Magnecore compition wires. I also purchased the interesting CRC mass air flow cleaner.

I spent about an hour cleaning the entire engine then got started. I first removed and cleaned the MAS very carefully and completely. I replaced it and covered the opening with some Cling Wrap to keep dirt and things out of there. I then continued with replacing the wires and plugs. The plugs were pre-gaped and the wires were very nice to work with and went in without any issues. Props to magnecore. Removing the old wires and plugs was the only part that wasn't fun. Covered the new plugs with a bit of anti-seize and dilectric grease stuff on the contacts. 16 plugs and 16 wires was a lllooonnng job.:o

So I cleared the codes and fired her up. Upon the first start there was no hesitation or roughness at all. 5 minutes into my first drive I found my ESP light blinking again...she's back!!! The car now runs like the day I got it. I slowly forgot how fun this car can be!! The codes have yet to return as well. Thought I would share my luck.

[machomachacho]

cool man.

this month i've done replaced the MAS, sparkplugs, ignition wires, and next on the list are the o2's and coilpack.

Originally started out with codes 300 and 302, but after reading all the mbforum, mercedesbenz sites i too figured it was the MAS...

yesterday she decided to throw me a 141 and 155 (downward heater o2 sensor) @$#! so slowly but surely i'll fix the dreaded/mysterious off the line, suddenly misfires and shakes and shudders, restart ignition at the next light, problem gone BS with our benzos. GLad to hear yours was an easy one.

[rman]

i'm reading all these threads about people replacing this and that, and wonder how much better my car would run if i did a full tune-up.

i've only had it for less than 3 weeks.....but it's got 91,500 miles on the clock....The idle isn't the smoothest, but compared to all the other vehicles i've owned in my life it's pretty smooth.

I can feel my idle miss a little bit, but it's just not very obvious to me. I mean, i used to drive a ford and when it idled rough, you knew it.

With a miss would you all suggest plugs/wires? or a MAS? Also my idle bounces a bit (in Drive) say, at a red light while my subs are pounding.....Cap? Alt? I've got a spare yellow top optima, wondering if that and an isolator will help any?

sorry to hijack the thread....it just got me thinking....

[dshenberger]

I did my plugs at about that mileage. They were the worst I have seen. From now on I will be replacing them every 50k or so. I don't think wires are an issue at that mileage, but the MAF may start to act up before too long. I was getting a fuel trim code so I replaced mine. Just keep in mind you have 12 plugs, and they are sort of awkard to get to. I still wouldn't pay someone else to do them though. Another thing to note about chaning them is: the wires are a real pain to get back on. They come off pretty easily with gentle prying with a 17mm wrench.