I just bought a 1989 230TE and the car didnt even want to rev more than 3000rpm. Initially my mechanic adjusted the fuel governor and the revs went up to 5000 then 6000rpm. However after the adjustment the idling became smooth then within five minutes the engine started to shake and no CO adjustment can make it smooth. If you try to rev the engine, it will choke and die. My mechanic decided to install a new governor and so the idling became smooth and revs could reach 5000rpm to 5500rpm( still cannot reach redline). After 5 to 10 minutes the engine started to shake and no amount of adjustment can make it smooth. If you rev the engine it will also die. What is wrong? Please help?: (Engine temp 85 deg. cel.)