I have a 1995 Skeeter 190ZX with a Mariner EFI 175 motor that I recently purchased. The boat had set up for a while before I got it. It is not getting fuel to the cylinders. I can hear the high pressure fuel pump humming when the switch it turned on. I replaced the fuel filter and fuel is getting to it when I pump the primer bulb. The motor fired for a second when I sprayed starter fluid in a cylinder. I switched it off as soon as it fired to keep from messing up the motor. What do I check now?