I live in the snow country of N. CA and have been having hard starting on cold mornings. It takes alittle longer to crank anthen gets running after a little stumble. Is there a cold start system or injector that makes the fuel richer until the engine heats up. If not, any ideas on what to check? '99 expy, 258k 5.4, thanks

 

I'd start by either testing or just replacing the coolant temperature sensor. If this is off and not interpreting the temperature correctly, the the PCM does not richen the mixture as required for a cold start.