Two other things that could impact it:
1) If it takes a long time for your truck to come up to temperature.. When the engine is cold, EFI adds more fuel to the mixture.. When really cold, it's actually a lot more fuel.

2) Intake air temp again, more fuel when cold to compensate for dense air.

22REturbo.net




1988 4Runner
22RTE core, turbocharged, megasquirted...