hallo from greece
i have a japanese vitara 1991 and after swapping the engine _the same code g16a- everything was ok
I run the engine for aboyt 20 minutes everything ok
I change oils spark plugs filters nad then.................... nothing
The electician says its the ecu
I dont think its the ecu since sometimes i can start the engine
Kill the engine and then nothing
When turning on th switch i hear a rellay near the ecu cliking all the time ,when i dont hear it ,it cliks once and then silence i know it will start
This happens once every 1000000 times
Since i have a second one spanish model i decided to swap the ecu but
some difference in the codes
Does anyone knowns if the are compatible?

Go ahead and swap them - the important number is the top one - the 33920-56B70.

The electrician is right, it is the ECU, the constant clicking is the main relay as the ECU resets itself again and again.  Find a good electronic tech and have them open the ECU that's giving trouble - there's a high probability that it has defective (swollen & leaking) electrolytic capacitors - they can be replaced, and when that is fixed and useable, get the other one done.

thanks for the answer
i open the ecu thae one on the car and i coyldnot see anything wrong no leaks no blonw capasitors
but since they  are the same and theres no chance of blowing the second tommorow i will try it
after i fix the cables behind the drivers rear light all of them is\\are  full off corossion and 2 of them were cut
thanks again
sorry for my english

one more question please
heres 2 photos  of the wires that connect with the ecu
the colours are different

any problepm with that?

If both ECUs are 56B70 then they are the same. The problem with caps often can't be seen until they are removed from the board, the acid leaks out and erodes the trace underneath.