P0442 and starting issue

[dross99_si]

Hi guys, 

I have a 2007 Tahoe LT 4WD 5.3 flex fuel. The issue is a P0442 and intermittent long crank/no start after vehicle has been driven for a while. No issue with cold starts ever. For instance 1st thing in the morning it starts normally, I drive to the grocery store, leave grocery store and go to start vehicle it will crank forever and eventually start but rough/boggy/choking like either starved for fuel or flooded. I make several other trips after that and it may or may not happen again. Very strange. Any suggestions?

I have already replaced gas cap, EVAP vent valve & EVAP purge valve with OEM GM parts.

[riverbanks]

Try to determine which way it is,lean or flooded, fuel smell,black tailpipe that's rich,clean tailpipe that's lean,it helps with diagnosing

[dross99_si]

Never smell fuel 

[riverbanks]

Ok,try a key cycling,to energize fuel pump,key to run,not crank,2 or 3 times before cranking when it's bad behavior shows up

[sefiroxx]

Check temp sensor as well. It could be reporting cold and putting the computer into open loop (cold start with extra fuel)

[chem_man]

I would go back and check the vacuum lines where they connect to the solenoids/vales and make sure they are seated correctly and are not cracked.  Another thing you might want to check is to see if the area around neck of the fuel filler is rusted.