1994 Subaru AWD 4door saloon - put a used engine - the mechanic put the idling RPM low. After driving first time with the replace engine for 5 miles got check engine; Next day no check engine light, but the vehicle was vibrating lot when stopped at lights (annoying). Took it to the mech. Shop. RPM made 1000+; Now no vibration while stopping at lights but 1. The RPM goes high when I start the engine and 2. Vibrates when I turn off the engine. But the Check engine comes and remains steady (No blinking). Inspected and found RPM was high. He reduced it a bit. The check engine light came again after driving about 9 miles. Should I go by trial and error?
I have been driving this vehicle for 2+ yrs after I bought it from someone. Earlier engine died due to No oil in crankshaft.
I did not drive this vehicle in the last two months prior to getting the engine replaced.