2001 Chevy Express excessive fuel flooding

Secondary air check valve is what was diagnosed. There is to much fuel and van also idles high. Theres no problem when driving only in idle when starting. any ideas before I start changing all kinds of things. It is a 2001 Chevy express 5.7 vortec

I would go to Advanced or Auto Zone and get a loaner fuel pressure gauge. You may have a bad fuel pressure regulator,pull the vacuum hose for the regulator if fuel is in the vacuum line replace the regulator. Try this first before checking fuel pressure.