does it crank at all? Can you hear the starter solenoid actuating? Check the little signal wire on the starter, it is a spade connector and sometimes they can get pulled off, the wire loom is really tight there.

 

Are the symptoms consistent even when it starts? To clarify, when it doesn't start, does it seem as if all is normal and then you just get nothing?

If so, I'd say its likely to be starter/starter connection or that clutch switch.

 

agreed

sometimes if the starter is bad or had a bad spot (hence old guys hitting the starter with a hammer) it will only start randomly.... it is possible for a starter to over heat and some of the wires could be loose too..check it out and get back to us

 

Can you hear the fuel pump prime when it refuses to start?

 

No idea whether you guys have a factory fitted immobiliser but that's common behaviour for us in the UK when we experience this issue...a faulty immobiliser.

 

Is it even possible to push start an S2000? If it is, then same question if the battery is dead!
With fuel injection and a dead battery, the pump won't be pressurized.

 

Yes. You push it down a hill, put it in second, and then bam. Frankenstein start.

 

ok i was laying around with the car this past saturday and i got it to consistently start weather hot or cold by fideling with the starter switch and green connector on the cars harness side. also when it does NOT start it will push start just did it this morning.

 

yes and already jumped the clutch switch to by pass it on the cars barnes side. il do it again tho

 

ya i am going to have to check this, just been so busy with school haven't had the time.