Hello everyone, I have a 1986 F-250. It has the 460 in it and we just got done rebuilding it. We did the typical .030" over, Comp Cams Xtreme 4x4 cam, Edelbrock intake, Holley 3310-2 750 CFM carb, new Holley 80 GPM mechenical fuel pump, etc. The fuel pump is the weak link in the build so far. We just got the new motor in this week and got everything hooked up and went to start it, but no gas was moving through the lines. We tried to narrow the problem down by unhooking the line before the fuel pump and putting it into a gas can and seeing if it worked that way... well, no gas was pumped into the line between the pump and the carb. So we took the pump back off and pumped it by hand. It flowed a lot of gas that way. Then we decided that the pump was obviously working, so we took the whole front of the motor apart because we figured that it was the fuel pump eccentric. That was fine, but it was not the original and the bolt hole in the new one was a little closer to the canter than stock, which would make it have less of a "throw" so we put the stock one back on because we knew that it worked before. So this morning, we get everything buttoned back up and go to start it... same thing. Well come to find out, we crossed the lines going into the pump. WE corrected that problem with high hopes and once again were dissapointed. We have a brand new clear filter after the pump and it's not a cracked line problem because we had a 2-3 foot long piece just between the fuel pump and the gas can temorarily. We're at our wits end and my father's ready to take a sledge hammer to it. Please try to lend any advice you can to get my truck going. Thanks, Austynn.

 

OK, nevermind... turns out that hooking a vacuum pump up to the other end of the pump did it after all. It just needed to be primed. Now we just have to figure out why when it did try to start, gas spewed out of the fuel vent tube. It also didn't hep that the initial timing was about 50* off. Oh well it almost started but now we've got a bonfire to attend. Thanks anyways. guys.

 

Fuel coming out the vent on the carb is a sign of a bad float or a leaking needle and seat.