My Rx7 cranks but won't start.

I'd check the fuel pressure and prepare to replace the fuel pressure regulator once it's found to be defective~

check the incoming valve at the carb. can be stuck beacause dirty fuel filter

If you have spark, the crank sensor should not be the problem and as roy said check the fuel pressure regulator or if after tha reg. are gas delivery

Just becase you hear the pump pressure need be min of 32 psi just to start

my mazda rx7 wont start unless i add gas but wen it starts it sounds like its working on one rotor .when i remove the leading plug on rotor number 2 it does not seem to be getting fuel because the plug is still very clean.so what could be the problem

where is the income valve located?