Running rough and buzzing at throttle body injectors

Pumping a fuel injected car has no effect on the starting process. This sounds like the fuel pressure is low or the injectors are having problems. The injectors could be having trouble from sensors that tell them when to open.

Throttle body injection? replace the injectors. First check for power to them. 12 volts from one of the wires with key on

a bad distributor is the most common problem of stalling,rough idle and backfiring.

Sounds like you have an injector leaking. Have someone just cycle the key on and off to run the fuel pump but don't crank the engine. If you see fuel dripping from the injectors, unbolt the injector cover on the throttle body, remove the injectors and replace the orings around the injectors.

Chk. your egr. valve and see if its functioning, sometimes it gets a carbon buildup in the intake where it bolts on and also in the valve itself. Take it off and clean the valve with carb. cleaner and also clean out the intake with a screwdriver and shopvac, and make sure the valve works before you reinstall it, and also get a screaned gasget at your local auto parts store before you reinstall it in case you miss some particals in the intake it will insure that no particals will get into the egr valve.

It sounds like you may have a bad fuel pressure regulator. The fuel pressure regulator is in the throttle body housing and the throttle body in your truck works best at 13psi to 15psi, Any other setting will cause problems. Check the vacuum hose to the fuel pressure regulator at the throttle body and check the fuel pressure at the shredder valve. The way the throttle body works is for the first 75% of the throttle, the ecm uses the signal form the O2 sensors to control the air fuel ratio and tries to keep it to 14.7:1 but at full throttle it by pass the O2 sensor signal and runs the engine richer and advances the timing so you can drive with wings like red bull. The Map sensor then takes over to promote the engine to run richer so you don't run lean and detonation occurs. If there is a problem with your throttle body position sensor, map sensor. and fuel pressure regulator, then at WOT (skinny peddle down) you may be running to rich. The other thing to is if your fuel pressure drops at WOT you'll get a lean condition and then you'll have detonation ( Knocking) and the timing will be turned down to keep detonation from occurring again and that may be the cause if your check engine light too. First and easiest thing to do is change the fuel filter and add fuel injector cleaner to you gas tank, buy a throttle body cleaner and clean your throttle body to make sure you don't have varnish build up around the throttle body, just follow the instruction on the can. Throttle body cleaner not carb cleaner. Start with that and i hope we don't have to do any more to get your truck running like a rocket. Good luck and keep me posted. Be glad to help. 

have mass airflow sensor cked.

fuel regulator?

timing? if you've got gas and you've got spark, have you checked the crank/cam shaft position sensors? have you put a timing light on it to see if you might have jumpped timing?

since the car sat for 6 months it could be a vaccuum line the lines are rubber or hard plastic the tend 2 dry rot or chewed by small rodents, while the car is running listen 4 whistle or check for cracks or lines off completely