Toyota Corolla 2001 high idle - 1ZZ-FE

[Levin_corolla145]

Hey guys,

I recently purchased an Automatic 2001 Corolla  that had a rod knock on cylinder 1 due to a spun bearing, the engine was disassembled and the engine block and head were sent to the machine shop, the block was inspected, cleaned decked and honed, the cylinder head was also inspected cleaned and assembled by the machine shop ready for installation.

The engine had a lot of carbon buildup and oil gunk presumably due to the previous owner of the vehicle not servicing on time or at all. Every single component of the engine was cleaned from pistons, rods, oil pan, front cover etc. I then assembled the engine using brand new crank and rod bearings, new piston rings and the rods even had brand new small end bushings pressed, so the entire rotating assembly was essentially brand new and everything was assembled according to Toyota spec from their repair manual.

After the engine was assembled we installed the engine to the vehicle, attached all the wiring and all other accessories and components and cranked the vehicle with no issue, I then began bedding the rings by holding the RPM's between 2-3k for 20 minutes.

The car runs perfectly fine, the only issue is that when it warms up the idle stays between 1.5-1.8k RPMS and only when it's in 'P' or 'N', and that is only when the engine is warm, on a cold start it holds at around 1.1K rpms. Now if you put the car in gear the idle drops down to 900-1000rpms which is what the normal RPM should be, if anyone has an idea on where I should be looking or what to do that would be greatly appreciated. Keep in mind the throttle body and intake manifold were all cleaned as well, all vacuum lines are attached as well. Thanks.