I had th whole exhaust off to the manifold, and tried reving the car. it made no difference the same 4500 ish RPM. Very loud though!!!
I will have the ignition checked. Are there any DIY tools available to check this, or do I have to take it to a garage, and does it have to be a merc garage??
I take it from this that you dont suspect the oxygen sensor, or air flow sensor??.
What about rev limiter, could that be causing the problem??
If it helps, the car is sometime hard to start when it is cold, needs cranking twice, and reving when it fires to get it going. The car is also quite economical, about 26 -28 mpg on a good run.