i have a 87 rx7 gxl NA s4 5spd 72k. it has intake, headers (witch eliminates the pre-cat) and catback. the problem randomly started today, the engine cranks fine but wont ignite at all. i try pressing the gas pedal but that doent seem to help, it takes a bunch of trys before it starts. im thinking mabie the problem has to do with not having the pre-cat. i put a bottle of fuel injector cleaner in. tomorrow im going to check the injector connections and make sure the spark plugs are tight.
on a side note i believe this is with cold/semi cold starts, i may be wrong

thank you for the help