It's easy to check it if you have a meter. Need to pull it, but you've already done that. Need the FSM to check the readings range. There are three pairs of pins that orient to the three ring-things inside. You need to meter them. A bad ISC will throw a value out of range. Try searching too as I know it has been discussed on which pins to match in the connector, and the value range you should get.

If you get one, make sure it is for your 3.0 version. I think the one on ebay will suit you, as I don't think OZ got the 3.0 24V SOHC version. Over here we did in 95-96. I ordered an ISC from a shop that rebuilds them here. Se sent me one that was for 3.0 12V. He didn't know there were other 3.0s in Monteros.