Well I have a Silverado with a 305 in it. I have a miss that misses about every 10 seconds when its warm. I checked all the vac hoses and found no leak. I replaced the fuel pump, fuel filter, air filter, spark plugs, spark plug wires, cap, rotor, pcv valve, iac valve, throttle position sensor, egr valve, and checked the timing. And I still have the running miss. Does anyone know of anything else that can cause this. Next step is to get the injectors cleaned and tested. Then maybe the 02 sensors then im out of options. Please help.