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So i recently rebuilt the holley 94 carburator and replaced the fuel pump on my 1950 f1, but I am having trouble getting the pump to suck the fuel from the tank. I have ran a new fuel line from the tank to the pump. when I put my vacuum gauge on the inlet side of the fuel pump i get zero vacuum when i crank over the engine. I am not very familiar with older carburated systems so any help would be greatly appreciated! TIA
replaced the fuel pump on my 1950 f1, but I am having trouble getting the pump to suck the fuel from the tank. I have ran a new fuel line from the tank to the pump. when I put my vacuum gauge on the inlet side of the fuel pump i get zero vacuum when i crank over the engine.d! TIA
You should see vacuum at the pump inlet when the engine is rotating. What engine are we taking about?
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Have you had this engine running before ?
Try removing the fuel pump and operate it by hand , put your finger on the intake and see if it produces vacuum .
If it does it may be the fuel pump pushrod is too short .
yes the fuel line is behind the seat with the fuel line tapped into the bottom, it has a 8ba flathead in it, i can get the engine to run if i prime the fuel line, the engine will run but i have to keep my foot on the throttle a little or the engine will die. the engine will not idle.
i can get the engine to run if i prime the fuel line, the engine will run but i have to keep my foot on the throttle a little or the engine will die. the engine will not idle.
If it will start and run on the existing fuel supply, your pump is working. It may not be working as it should. Have you adjusted the carburetor since rebuild? Do you have instructions on carburetor adjustments? Will the engine speed increase with throttle increase? Will the engine run with the choke pulled part way out?
The more accurately you can describe your problem, the easier and quicker we can determine the problem and help you fix it.
To be honest i dont know too much about adjusting the carburetor. i have messed around with the 2 idle mixture screws but they dont seem to do very much unless i tighten them both in then the engine will die. the engine speed will increase with throttle increase, and it will run with the choke pulled 1/4 of the way out. if i push the choke right in the engine will die. i also have the vacuum port that goes to the windshield wipers plugged. if i quickly put my foot to the floor the engine dies aswell.
Basic adjustment of the idle mixture screws is 1-1/4 to 1-1/2 turns out from lightly bottomed.
Raise your idle speed on the passenger side of the carb, there is a screw that bears on the choke operating arm.
With a full tank of gas, the fuel level in the line will be at about the exhaust level on the engine. A good pump will suck gas up the line to the pump inlet in a few revolutions while cranking. I suspect your pump either has junk on the check valves, or a leaking diaphragm.
The fuel tank and valve at the bottom of the tank were cleaned prior to install in the truck. As far as the idle screws on the passenger side of the carb the screws is tightened all the way in and it barely touches the adjuster. I have attached pictures.
I should also note that those pictures were taken before the carb was taken apart and cleaned, but the linkage setup is still the same. I will pull the pump off this weekend and try everything you gentlemen suggested. I really appreciate the help, I just want this old girl to purr like she did 69 years ago.
Back to the main issue, though....you say there is no vacuum on the inlet side of the fuel pump when you attach a gauge there? This still has me leaning towards a fuel pump issue...bad diaphragm, gunk inside of it, or push rod not actuating on the cam correctly.
