I got a 98 4 door blazer ls and I've been havin some problems starting it when it is cold out. It cranks over every time I turn the key but it won't start.....some times it will start but stalls out after like 10sec....when the temp outside is about 40 or above it will start fine and run great but if it is below that is treats me like ****.....any ideas what it could be?

 

Look-tune the thing up! Perform all maintenance points-if you do it yourself,maybe $200 and 3-5 hours learning about your Blazer/Jimmy-and you will be pleased with the results!
Go to it!

 

I know a lot about it cause i did give it a tune up all new plugs,wires,coil,oil change,rad. flush, I think it has something to do with the fuel system.....maybe the filter or injectors .....fuel pump works fine ....I was just lookin for some help cause its to dam cold to be outside dickin around findin nothin out.....

 

i had a similar problem with a car i once owned, weather warm it would start no problem and continue to start throughout the day,
cold morning it would turn over but wouldn't start, but when i got it started it would start right up all day long.
anyway to cut a long story short the problem was the starter,apparently it was daining to much power that there was not enough left to power up all the other electrical components needed to start the vehicle.
hope this might be of some use to you.

 

Could be moisture in the fuel that freezes-up. You could try adding a can of Heet to the fuel.

 

Have you tried replacing the relays on the firewall on the passenger side?