My 87 iroc 305 tpi is has trouble starting at times. It has alot of hesitation when you give in throttle and when its in neutral or park and you rev it up the engine wants to shut off when the rpms come back down. So far i have changed the fuel filter, plugs,wires, cap and rotor. The electric fans stay on constantly. I'm not sure if the coolant temp sensor could cause this or it might be the timing is off. any suggestions?

 

when i was experiencing similar issues i found trouble with injectors. also do a search for IAC while you're at it