It has high idle at start up.

Hello, sounds like an air leak to the intake manifold. When a large amount of air comes into the intake, either from an intake manifold gasket leak or another un-metered air leak, the idle can get uncontrollably high. This is because the leak of air coming in can't be controlled, and all the engine's processor can do is provide more fuel to compensate for all that air, raising idle speed. Have this inspected. www.repairpal.com/repair-shops