hello all new here, dont know what else to do. this is my last hope before puting truck in shop. so here we go.
2002 chevy tahoe ls 4.8l vortec 136K
about a month ago it started this issue. it wont start when cold outside, about anything less then 40 deg. it will crank but no start. sounds like no fire.
once it warms up later in day it will start just fine.
it is strange because when this started it was cold out. but not the coldest temps this year. and it never had this problem before.
it was due for some service anyway so i went all through it.
new plugs
oil change
fuel filter
air filter
cleaned map & trottle body
new crank possition sensor
new temp sensor

the fuel pump was replaced @ a year or so ago. and is still working fine can hear it prime everytime key is on.
so i'm stumped! so fire away boys. thanks!

 

I don't know if it has an idle air control valve?

 

thanks for the reply. 109 views with no reply i was wondering!?
i assume your saying to check the IAC? can you elaborate on that?

 

Test the engine coolant temperature (ECT) sensor for being shifted in value. Connect a scan tool. Compare the engine coolant temperature against the intake air temperature (IAT) on a cold engine. The ECT and IAT sensor values should be withiną 3°C (5°F) of each other. If the ECT sensor is out of range with the IAT sensor, check the resistance of the ECT sensor.