help with milage and acceleration problem
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Joined: Oct 2014
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359e00a1@opayq.com
help with milage and acceleration problem
okay, had to re-register since it has been a while... i have an 01 c240. my milage during city milage has dropped 4mpg, my mpg at freeway speeds is great (33mpg). when i accelerate under loan in gears 4, 5, and six it is sluggish and i note some surging at cruisin rpms {2500-3000), and it takes like forever to punch up in the lower gears from starting under loads. Manual trans guys! 187K miles. Loads of recent repair making up for the age, all new rubber hoses, new O2 sensors with the left bank upper left to replace, new bottom o-ring rubber gaskets on all injectors, replaced the air manifold gaskets and valve cover gaskets. Zero codes!!! What could cause mild surging, poor load acceleration, and lower city mpg???? No cat rattle or rotten egg smell. Has me baffled! I have the dash command app and the fuel rail pressure seems to be bouncing from negative to positive in even numbers and intervals. fuel pump replaced two years ago.... i am at a loss. I don't want to just throw cats, coils, and injectors at it - I just spent $2k refreshing a lot of worn out but not broken parts (well, except for one valve hose that was not shown in the parts list at Autohauz - man, that thing was TOAST)
Senior Member
Joined: May 2014
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From: Jersey City, NJ
2001 C320 w/ Sprt Pkg
You're in the same boat as me brother. On the highway she is excellent. I can squeeze out over 400 miles a tank. In the city, she's like driving through quick sand. Horrible MPG, and the overall feel is sluggish. I've had people suggest either the fuel pump, fuel filter or maybe even the cats are on their last leg. All assumptions....
If you find out, please share it, as will I if I do!
If you find out, please share it, as will I if I do!
Thread Starter
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Joined: Oct 2014
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359e00a1@opayq.com
not the cats
so i popped by a reputable muffler shop here in austin. he stated that you would know when there is a bad cat on a w203 - it would rattle like a **** and you would have acceleration problems in neutral just revving the engine. i am beginning to suspect i have an injector with a poor spray pattern that clears up under heavy acceleration (otherwise it would not accelerate perfectly from 3500 to 6000 rpm like it does in first, second, and third).
Newbie
Joined: Oct 2014
Posts: 7
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From: Houston, TX
2004 Acura RSX (totaled); 2007 Mercedes-Benz C230; 2006 Acura RSX
My c230 shakes soon as I hit 60 mph or higher on the highway and my check engine light keeps coming on. The shop said it was the camshaft sensors but it was replaced, yet I'm still having the same problem..and my gas mileage is awful on the highway.
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Thread Starter
Newbie
Joined: Oct 2014
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359e00a1@opayq.com
oh, duh...i see you live in Tx. as well! Overall is 22 (down from 25). i guess you can say i am hyper about routine maintenance. i just went thru a major refresh under the hood, all new vacuum lines replaced, new plugs and wires, replaced the air intake and valve gaskets, replaced everything in the cooling system, new front and rear shocks (Billstein) and new rotors and ceramic pads.
that milage is at 70mph, meaning a clear freeway - NOT commute milage.
that milage is at 70mph, meaning a clear freeway - NOT commute milage.
Last edited by atxmike63; Oct 27, 2014 at 01:21 PM.
Thread Starter
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359e00a1@opayq.com
so, replacing the four coil packs that were origonal helped a LOT. smoothed out acceleration and city milage is improved. it's not as good as new, but I can live with what i have. I broke my rule and bought non-oem packs. Bosch were $55 each, I got four for $80 delivered.
