5000 Hard Starting when cold

[Eckfeldt <eckfeldt@snet.net>]

I have an 87 5000CSTQ with high miles (257K) that won't start when cold.
Even in the low 20's it turns over fine, but doesn't fire. If it goes above
30 it starts fine and runs fine. Any ideas on where to start looking for
problems? Also any recommendations on engine heaters? I was told by one shop
that it was not recommended. My wife is nervous about not being able to
start when it gets to 20 below as it does sometimes. 

Thanks in advance.

Grant
Grant Eckfeldt
eckfeldt@snet.net