1998 175 efi motor will not keep running in temps below about 37 degrees. At temps above that it starts and idles fine. It will start and die, can't get to rev up unless I start it about 25-30 times then have to play with throttle to keep running. After it warms up all is fine. Checked air temp sensor engine temp sensor. Fuel psi is 39. New fuel filter. Always run pure gas or add stabil 360 on few occasions I couldn't get pure gas. Always kept in heated garage. HELP