The good news is that today I put the part back on and it seem sthat all work good - seems like the idle problem is solved ! 
The bad news is that the low power problem and the strange sound from the low part of the engine specially on uphill (sound that reminds an old beatle car whlie driving) - is still exists...I looked for the OBD1 connectors for the check and found those 3:
Didn't make the DTC check because didn't know which one of the switches to use
and what to do with them exactly ... seems like need to use the one of the first two...
Going to read more about it...
Any tips will be very appreciated
According to the videos on youtube the electrolisys can do magic with removing rust...
Here is 2 videos:
https://www.youtube.com/watch?v=qi8qIxK4IlA
https://www.youtube.com/watch?v=q_fAauPKH4o
There is 2 options to make the liquid:
1. (my option) Water + Cleaning soda
2. Water + distilled vinegar + salt
Made in Japan Suzuki Vitara 1997, 4x4, 16 valves, MPI EFI, 4 speed, Automatic, 1.6L, 5 door, from Israel, VIN: JSAETD01VV1200XXX, market: E54