I have recently purchased a vti del sol.

The old owner had just replaced the engine. And now i am stuck with a problem.

When the engine is started and cold the idle is between 2500 and 3000 until it is warm then it is at around 250 rpm. There is no check engine light.

Also the gas mileage is really bad. 7 km/liter.

And finally the engine sputters/misfires while downshifting around 2750 rpm.

Please help!!