Hey guys need some help with my 97 TF Magna 3lt v6

My old car 97 TF Magna which my sister now owns had some issues a couple of weeks back and well short story the motor died after it had no oil.
We changed the engine to the same one just out of a car that was 98 still TF which runs fine no probs there but we have been having issues with the idle.

It seems to like idling at 1800rpm not the normal 800rpm when warm even when cold it idles at 1800rpm.
Things ive tried so far to fix it adjust the idle screw that actually took it down from 2000rpm idle initially when we started it.
This also seems to make it drink more fuel from what my sister has told me.

Any suggestions or anything else i might have missed or way to check why its idling so high.

Thanks

Idle motor is buggered, change that.

Which part is the idle motor i know all the parts on the throttle body but not sure which one would be the idle motor is it the one below the throttle body or the one on the left side just below the idle screw ?

idle motor is a 6 pin plug under the TB, 2 x 8mm bolts and an "o" ring inside. change with a known working one

Not for 1800 rpm, the idle motor will not do that

i would say you have a good size vac leak, check your manifold gaskets, dont use paper ones, only use metal ones. check your vac lines in particular the booster line. Check that the manifold does not have an open EGR port, there should be a blanking plate if it is a 3.0

Check the throttle plate is closing completely, could also be the bypass valve, the bit the coolant hoses pump coolant through

Well i found one hose that wasnt connected which was the manifold recirculation hose which goes to the intake just before the throttle body dont know how we could have missed that but even after doing that idle was no better.

So will have a look at all the hoses that go to the throttle. With the booster hose u mean the one for the brakes that goes to the brake booster?
Yes i checked the throttle plate as it initially was getting stuck closed quite badly a bit of build up of dirt around it which i have since cleaned and is now opening and closing fine.

Ill have a look at those bits tomorrow will most likely even take the manifold off again to ensure its sealed tight.