I'd think that the "crankshaft position sensor" alone - would handle all fuel-injection, spark timing matters. The cams / crank are, after all - pretty well chained or belted together. (This might be a wrong presumption re those CVCC and other engines with variable valve timing.)

Now on my '94 Acura - the only sensor near the cam (which is in the head) is a "knock sensor". Its signal (as all the others) is sent to the "engine computer" -- every maker has different acronyms for these boxes. Actually: there's a front one and a rear one.

Their purpose has nothing to do with camshaft position: it's a bloody microphone; it detects the bad-sound of detonation.. or 'pinging' == from too low-octane fuel. ('Too low' for conditions: depends on engine condition, outside temp and load, like say, uphill.)

Pinging means that, if prolonged - damage to piston crown will result; not long after that: total engine failure. So the computer retards the spark timing until it stops. This is a common way of allowing an engine designed for premium fuel - to manage on regular. You don't save $ buying the cheaper gas, because: you'll use more (!) But at least you won't do expensive damage to the engine guts.

You need to find out if the above -- is what your "cam sensor" is really doing. And if a new one is expensive: try the wreckers. Knock sensors don't usually 'wear out' - maybe a wire breaks in the small coil. And they usually are expensive. Because - what choice have you?


Luck,

moi