Here are a couple of things you can check with basic tools.
1-The fuel pressure regulator is located on the fuel rail over cylinder #8,
pull the vacuum line off and plug,with engine running check for any fuel from the vacuum nipple. If any fuel leaks replace regulator!
2-Pull one or more plug(s) and check that they are not resistor plugs. If they are replace them.
3-If you have access to a vacuum pump apply vacuum to the EGR valve,
Pull the line off quickly and listen for the valve to snap shut (metal on metal snap). If not your valve may be bad.
Any of these can cause poor idle conditions.
Mike