Alrighty so I had to replace my old fuel pump because no fuel was going through the fuel filter and obviously not to the carberator (my set up is spliced filter disceting the carberator fuel feed from the pump) so I purchased a new pump installed it after I flushed all the fuel lines and the tank a couple of times and my truck ran like a charm for 2 days and then out of nowhere it started to have the same problem again, with the same exact symptoms.

I already know I should check the gas lines again and how much vacuum the pump is getting. I also know that. The cam lobe could also be a problem. I was wondering what you guys thought could be the problem. Any suggestions are welcomed and very appreciated
Note: I have a 62 f100 FS with a 223 (I6)
Here's my set up, also note that I have connected the gas feed hose to the pump I know it's absent in that picture
- See more at: http://s1317.photobucket.com/user/JohnTheDigger/media/4B92A7E0-8346-4035-B7CB-80DF3A301786-773-00000057AED97B31_zps02fdf399.jpg.html?sort=3&o=3#s thash.hK5AVesg.dpuf]4B92A7E0-8346-4035-B7CB-80DF3A301786-773-00000057AED97B31_zps02fdf399.jpg Photo by JohnTheDigger | Photobucket

Thanks,
- John

 

One easy thing you can try is to pull the fuel line off the carburetor, drop the line into a glass jar and have someone turn over the engine, you should be able to see the fuel pumping out of the line, if it seems weak your problem is somewhere in the pump, line or tank, if it pumps strong the problem is in the carb. You can also try to disconnect the fuel line to the pump and gas should gravity feed out the line, if not the problem is either in the line back to the tank or the tank.

 

Although my truck is a '66 V8, I went through the same sort of fuel system corrosion and clogging hell that you're going through, including the same "works good for a few days, then back to the same poor running engine" deal. One of the cheap design features of our truck is that the fuel tank pick-up tube that sticks down into the bottom of your fuel tank does not have a screen on the opening, thereby allowing crud from inside the tank to clog the tube partially or completely, or let crud pass on farther up the fuel line or into the filter or filters, depending on how many you have (if your truck is stock, don't forget the one at the entrance to the carb). Fifty year old trucks are gonna get dirt and crud into annoying places or just deteriorate due to age. At least your fuel system is not complicated like on modern cars. Sounds to me like you'll just have to keep after cleaning your system out. I wouldn't change the fuel pump again - it worked satisfactorily for a couple of days so it's probably not the culprit unless crud has gone in and blocked it. Have you inspected the inside of your tank with a flashlight? There are three openings you can use - the first being the fuel filler, and the other two are on the top of the tank where the fuel quantity sender and fuel tank pick-up are. Don't mess up the gaskets. Do the check "likeagoodbook" suggested first and then work your way backward, logically, one step at a time. You may also have to take the top off your carb to see if crud has entered the float chamber. It's a long, frustrating process, as you've discovered, but your engine won't run well without a clean fuel system. Good luck!

 

If the rubber hoses are not new, then replace them. You can islolate the tank by placing a hose in a gas can to the pump. On my 390, I installed a temporary inline pressure gauge between the pump and the carb. I was surprised to see a steady 5.5 lbs of fuel pressure at all throttle positions. Good luck.

Kurt