94 d21 high idle PLEASE HELP ME!!!!

I have a 94 nissan D21 with 2.4L with which seems to start and run great until it is warmed up. The motor Idles between 1000 to 1100 which is fine but Once the motor is warmed up the idle increases to about 1700rpm.

If you continue to drive the truck the idle will eventually settle down to 1000 but will usually increase all on its own back to 1700rpm without touching the gas pedel.

I have READ LOTS OF POSTS and have a great mechanical knowledge but cant seem to fix this isseue.

- I have cleaned the TB with cleaner
- Cleaned / Oiled throttle linkages (Nothing sticking)
- Did remove and clean old IAC valve
- Ended up replacing IAC valve with new one
- Bent the indicator for the wax kit, very hard to explain but I have removed the cold start linkage so that it CANNOt open the throttle body
- Replaced the cooling temp sensor
- Replaced the O2 Sensor
- Replaced air filter, Fuel filter
- THERE are NO ENGINE CODES

I give up!!!! I keep replacing part after part but no luck. I have tried to feel and inspect ALL vacuum lines and cannot find anything that is broken or cracked etc.

I know that someone has posted to try and ground a couple wires from some harness and that may solve my problem but I have NO IDEA what wire or wire colours I need to try and ground.

ANY 1 HAVE THIS PROBLEM??