Wont rev

[uhayat]

Hi all,

My first time posting. Something has gone wrong with my 1998 C-180. It starts first time everytime but then when I press the accelerator it does not rev up. Starts to misfire, sputters, shakes and all. idle is almost perfect, no misfire, no shaking etc.

If I put it in 'D' i can drive it all day (at idle speed :)) without pressing the accelerator. If i try to rev it, shakes, misfires etc etc.

Please help I'm in a fix.

p.s I had a set of (i know working coils) and have changed them with no luck. MAF is also fine (tested on another car). Also have put new plugs.

[Denlasoul]

If the plugs are good, look into your fuel filter and fuel pump.

[slowpoke]

yup, could be the fuel pump or filter... you could try checking your fuel pressure regulator also...

[uhayat]

thanks guys. I have replaced the filter with no luck. Will check the pump and the fuel regulator next.

Regulator is the small cylinderical thing with a vacuum pipe on the fuel rail - right?

[Cru328prod]

haha you cant just test your MAF on another car......well what type of smoke comes out of your exhaust for 1? black, white? also whens the last time you changed to sparkplugs.....Merc claims there wires are lifetime....but it still doesnt hurt to change them now and then...is the CEL on too?

[Denlasoul]

Originally posted by Cru328prod
haha you cant just test your MAF on another car....
Sure you can. If I put a bad MAF on my car, for sure it will throw some codes. This should apply to this car as well.

[Cru328prod]

it depends on the how much damage is done to the maf.......sometimes it won't even throw a code....


I think you should do a "seafoam treatment" see if that works first before you start replacing shit...that shit works wonders

[slowpoke]

Originally posted by uhayat
thanks guys. I have replaced the filter with no luck. Will check the pump and the fuel regulator next.

Regulator is the small cylinderical thing with a vacuum pipe on the fuel rail - right?

yep, that's the one. you'll need to de-pressurize the fuel system first though.

you can unscrew the gas cap and/or release the pressure via the valve next to the regulator. its covered by a cap but looks like a schrader valve (used in bicycle tires).

you'll also need a pair of snap ring pliers, as you will have to remove the snap ring holding the regulator in place.

btw, it's best to work on a cold engine because if you forget to de-pressurize the fuel system, removing the regulator will spray a fair amount of gas out of the regulator's receptacle.