Car overheating while engine is off

[fixkick]

The dashpot retracts too fast.. About in 4-5 seconds.
After that, rpm stay on 1100-1200.
If I press gas pedal (just an hit) they go to to  750-800.
I tried another dashpot with no luck.
Can be a TPS problem too? Cause a mechanic removed it too clean the TB... dunno if he put it on again in the right position...

the DP can in fact retract in 3 seconds,  the time the DP lasts is based solely on the temperature of the engine cold.  -40C to +82C,  faster when hotter engine
then the IAC rules cold start RPM (below 71c)
boy that is  ODD that throttle hit thing, never seen that ever. (but smacks as idle switch failing) 
what matters is the engine temperature when engine is started.
if the mechanic removed it and did not do the calibration , now the idle switch is set wrong,  it must be closed this switch after the DP retracts.

below 150F (71C) the IAC is open and idle must be fast, or the IAC is dead.  coolant temps are what matter here.
when testing the idle always know what the coolant temps are,  I use a ohm meter at the ECT (unplugged.)
750RPM is wrong on any 8v cold engine , means IAC is dead.
or use  IR gun to read thermostat housing temperature before starting so you know where it is starting temp. wise.

here is the table  I made for USA cars , many cars in EU have different ECT. sensor,, type1,2,3, etc. no country or VIN told by you So all I can do is guess.
at 21C the ECT reads about 2300 ohms , fully hot 81c is about 300 ohms.  


https://fixkick.com/ECU/temp-sensors.html


the IAC must be open on cold engine, at end of DP cycle, up to 71C it is open, (less warm) and fast idle.



TPS 8v calibration is here.

https://fixkick.com/tps-testing#8V_Calibration

TAGs (body)
USA has no such tag ! outside yes.
do you have this?  this is on the fire wall on all non USA Vitara's  and engine parts (EFI for sure) must match these codes.   NO VIN here, just chassis codes.