Air Mass Problem

[championlad]

Hi,
I have a 1996 C180. The engine had a pinging coming from the engine so i replaced the Air MAss Sensor. it soted the problem and ran ok for a bit. now i am having these problems.
The Carb Spit on 1st start till its warm.
When its warm and i sit and rev it only gets to 4000rpms and then just stays there . i get the feelin of loss of power when driving and if i swtch off and let cool for a bit then start to drive again when at the lights or stopping the revs will dip to nearly stalling point then jump to over 1000 then back down. will do this for a bit then go stable.
I dont want to have to pay a frotune to diagnose the problem. please can anyone help............
Can it be a faulty air mass sensor. or something else.

 

[mightymerc]

hi just to advise you when your car while you sit in it when warming up and in neutral it will only rev up to a maximum 4000rpm. It is meant to stop at that you cannot possibly change that when you rev it as thats the most it will go up to. Its normal but in neutral. I had one problem similar to what you are describing occasionally my car would rev up itself to the highest 4000 rpm when stationery at the lights after warming up and stationery or coming to a stop. I had to hit hard on the accelerator to derev it or switch of the engine and restart. However my car was misfiring too and losing power. I changed the spark plugs and plug caps only it did the trick. No misfire no over revving when warming up and stationery at lights, no loss of power. Now it just drives beatifully.