97 blazer hard start when cold now it wont start and when it does runs at 3000rpms
 

Got the truck 3weeks ago. Have to shoot iether in it to start when its cold for first start of the day.. then we had a snow storm and when it catches it runs at 3000rpms then just dies out put in a fuel filter in seems to have ok fuel pressure. Dont know whats going on with it but its driving me nuts anyone know what would make it do this?

did you do a fuel pressure and leakdown test?