I would check the fuel pressure which this guide can help with should be about 48-52 PSI. You can rent a fuel pressure gauge from the auto part store. Here is how the job is done, and I included how to service the throttle body in this video as well.
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.