I have a 1981 ford f-250 with a 300 straight six and 2 fuel tanks thats not getting fuel to the carb. I have checked the engine mounted mechanical fuel pump and it is operating properly and the strainers in both fuel tanks are clean. I am getting very small amounts of fuel at good pressure to the carb. But it is mostly air. What do you suppose the problem could be?
Use compress air and make sure supplies and return lines are all clear. Then place a transpant hose on carb inlet. Crank and watch the fuel move into the carb. Also place a fuel pressure gage between pump and carb. If u are not get over 3.5 -5 psi or see bubble into the carb. Ur pump is junk. And please be specific when u say cpts that are chk out. What method did u use.A visual chk out is not 100% positive. Wehave more customers or even shop swear theyhave good cpts or chk out and it turn out otherwise after we went 1000 miles of circle. Iif u wanna eliminate the possiblity of bad tankor junk in the tank. Then just use a can of gas and a siphon hose to the pum and see if ur engine will start. God luck man