engine wont start

under the intake there is a plug for the knock sensor.it is commonly for got and will not run if it is un hooked.it is located on the right hand side of the in take (if your looking at the motor)and the wire should stick up out of there.this is on 3.0 toyotas.let me know how this works out for you.

Scott is right about the knock sensor harness frequently being forgotten to be attached, another thing I have seen is these harness frequently deteriorate once disturbed during replacement of the head gaskets, they just heat cycle and deteriorate, our dealer always stocks them I think $18.