Mercedes-Benz Forum banner
Cancel

Acceleration Problems. CPS, MAF Sensor? Tune Up?

6591 Views 14 Replies 7 Participants Last post by  DO_Doc, 
X
Well I bought an 04' Crossfire in December (3.2L, Automatic) and have had a lingering problem that no one seems to have an answer to. Keep in mind I have no warranty or the money to just blindly start replacing a bunch of parts. It just rolled over to 40K miles, so I'm hoping it must be something small I can fix myself.

First off, it seems I get much lower gas millage than normal 320 owners. No matter how I drive it, I never get no more than 250 miles to a tank which I'm guessing is around 16mpg. This is mainly city miles but still my driving style or more interstate trips doesn't effect it. The car always cranks fine, and early in the morning it seems to run best with no abnormal activity. During the day is a pretty huge decrease in performance. Some days I feel like I'm pulling a trailer it's so bad. I live in FL so of course the hot temps will make a difference , but I've never been in a car where it's been so effected.

Basically, when it's hot like this, the car acts up worse. When giving the car slight steady gas, it feels like it misses, or goes in and out of gear. You can watch the RPMs go up and down slightly and you can hear the engine going up and down (passengers can easily hear and feel this happening). It just kind of lurches forward. I used to think it did it worse around 40MPH going to 50, but really it'll do it whenever. When you put it in sport shift and leave it in a certain gear, it still does it, but not really at high RPMs. Under heavier acceleration it's pretty bad. Sport shift is also very rough in my car, and does a lot of hard shifting and knocking, I never really use it. It seems to act up much more when I do.

I can't believe with the millage the transmission would be bad already (or at least the TCM on it). It sounds more like it could be the MAF, but I don't know if the spark plugs could be bad as well. As much searching as I've done no one has really had the same symptoms as me, except for one I read and he had a bad crank position sensor. My car has never stalled on me before.

Anyway, any help at all would be GREATLY appreciated. I'm just looking for some positive answers before dropping $$$.
See less See more
Reply
Save
Like
1 - 5 of 15 Posts
X
I bought some CRC MAF cleaner already. I don't have any of those security torx bits, so I guess I'll go to Sears or something today and pick them up. The cheapest thing out of the way first .

Yes, I have no CEL. I didn't think there would be codes thrown without one present. I guess I'll go to Autozone too if the cleaner does nothing.

As far as driving in the rain goes, it's definitely acted up in it. A lot of the time I turn traction control off because it almost feels like it interferes, like it's the TC that makes it do it (feels very similar really). I almost feel like it does something to fix it, but maybe it's a mental thing :p. lol. I'll see how this goes before taking a plug out. I guess it wouldn't be out of the question I'd need new plugs at 40K miles...
Reply
Save
Like
X
haha, seriously though, I kind of regret getting this car already. It was too tempting for $14,900. Now I realize the cost to own and all of the repair prices are out of my league. I just did an oil change myself and it was still like $100. I think If I saved a few grand before hand and just bought a C5 Vette, I would have actually saved money and had the power of an AMG at the same time ;). I figured I wouldn't need to replace anything major until it was payed off since it was so new, maybe I'm too used to my Hondas I had.

No luck getting those security torx at Sears, I'll have to stop by some other places later.
Reply
Save
Like
X
MAF is now clean. I just took the entire plastic throttle body piece off, and then used a pair of pliers to unscrew the torx. It looked dirty to me, and it seems cleaner now. The part on the middle of the sensor (the big flat surface), there is a decent sized discolored spot that wouldn't come off, I don't know how important that is. I also went ahead and removed the plastic and metal mesh to help complement my intake.

I took it for a ride and seems fine for now... I'll drive it for a day or two and see how it goes, and let you guys know if it did the trick :thumbsup:
Reply
Save
Like
X
Well just an update... the car still acts up a little bit, but not near as bad as before, and not as often. The performance during the day has been way better and if I continue to get the gas millage I have been, I think I'll see an extra 50 miles out of this tank than anything else I've gotten since I've had the car. Maybe I didn't clean it well enough, is it possible some can't be cleaned perfectly and just have to be replaced?
Reply
Save
Like
1 - 5 of 15 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Mercedes-Benz Forum
BenzWorld.org forum is one of the largest Mercedes-Benz owner websites offering the most comprehensive collection of Mercedes-Benz information anywhere in the world. The site includes MB Forums, News, Galleries, Publications, Classifieds, Events and much more!
Full Forum Listing
Explore Our Forums
W126 S,SE,SEC,SEL,SD,SDL Class R/C107 SL/SLC Class W163 M-Class W124 E,CE,D,TD Class W210 E-Class
Top