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Discussion Topic:
Fuel Pump Rod
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JM |
09-06-2013 @ 9:07 AM
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Senior
Posts: 823
Joined: Oct 2009
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A lot of good suggestions have already been given. If the fuel pump suddenly stopped working I don't think the push rod would cause that unless maybe it somehow seized in the guide bushing which is unlikely. Also, I am wondering how you know the fuel pump stopped working? It's possible that something else failed and is causing your problem. Another thing to consider if you do put on a new fuel pump, make sure it is pumping the correct psi for the carburetor you are using. Some new pumps on the market are pumping ~ 8 psi while some carburetors can only handle 1-1/2 to 2-1/2 psi. Also, if you find crud in you gas line, consider pulling the tank and having it cleaned.
John
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TomO |
09-06-2013 @ 8:19 AM
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Senior
Posts: 7256
Joined: Oct 2009
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Do you have the pump with the glass sediment bowl? The bowl must be tightened finger tight to seal properly. Some pumps are shipped with the diaphragm screws loose.If this is the case, operate the pump several times and then with the diaphragm relaxed, tighten the screws in a pattern that alternates sides. Check for vacuum at the input to the pump. If you have vacuum there when cranking the engine, your pump is installed correctly. Check the flex line by trying to blow through it with your mouth. If you feel resistance the flex line is bad. It could also have a vacuum leak, so check for vacuum at the point where it connects to the tank line. If you have good vacuum at the input of the flex line, you line from the tank or the pickup in the tank may be plugged. Disconnect the line to the tank at both ends and use a compressed air source to blow through the line. If debris comes out of the line, you will probably have to replace it with a copper coated steel line available from Roy Nacewicz.
Tom
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supereal |
09-06-2013 @ 7:42 AM
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Senior
Posts: 6819
Joined: Oct 2009
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Be sure the rod is in the cup on the end of the pump lever. It is easy ti miss it. I prefer to remove the pump stand, bolt on the pump, and install the whole thing. It can then be set down on the rod without trying to find the cup in the confined space. It is unusual to find a worn out rod, as the end that rides the cam has a constant oil bath. We used to put "pills" in the pump cup when the pump was weak, and new ones were scarce. My guess is that the old pump quit, and the new one wasn't installed properly. Some replacement pumps now have an odd lever, for some reason. You can connect the pump to the fuel line before putting it on, then pump it by hand to be sure the fuel line isn't blocked. Alcohol gas is causing a lot of that, today.
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kubes40 |
09-06-2013 @ 7:28 AM
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Senior
Posts: 3407
Joined: Oct 2009
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Did you remove the oil 'sleeve' that is pressed down in to the hole in the manifold? If not, it will block the removal of the push rod. That "sleeve" comes out easily but you may have to start it with a light pry of a screw driver blade.4dfordsc is correct in that usually the rod is okay. The old trick of placing a piece of leather in the arm of the mechanical fuel pump is tried and true. It nearly always does the trick. If the lobe on the camshaft is worn, well, that trick won't work. Does the rod go up and down when you turn the engine over? If I recall correctly (oh-oh) it is supposed to travel about .200". I'd suggest you try the leather trick first. Other things to look for are a faulty flex line. They have a tendency to fail due to the ethanol in today's fuel. They may appear top be good but often will suck air through the rubber vs. pulling fuel through the lines. a quick check of this is to remove the flex line, place your finger tip over one end and suck on the other end. You should NOT be able to pull ANY air through the line. Your finger tip should get "suctioned" on to the end.
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4dFordSC |
09-06-2013 @ 7:06 AM
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Member
Posts: 266
Joined: Oct 2009
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Are you sure the problem is with the rod? If it moves up and down when the engine turns over, it should operate the pump. However, you might try an old mechanic's fix which was to cut a piece of leather and fit it into the cup on the fuel pump to take up any slack. Also, make sure you don't have a blockage in the fuel line from the tank to the pump by blowing back through it (remove the fuel filler cap first). Also, if there is an inline fuel filter installed, replace it. Hope this helps.
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dolmer |
09-06-2013 @ 5:48 AM
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Member
Posts: 10
Joined: May 2011
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The mechanical fuel pump in my 46 engine quit working suddenly. I purchased a new one, but it too wouldn't supply gas to the carburetor. At the suggestion of others, I tried to pull the rod that operates the pump to check it for length and condition. I was told it should just slide out. However, mine seems to have something attached to the bottom of it that won't let me just pull it up and out. So, has anyone run into this situation before and what is the solution. I was ready to pull the intake manifold but don't want to do that if it isn't going to be the solution.
dolmer
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