have 80 malibu w/bbc & a 750 holley carb w/vaccum secd...electric choke...has new holley mech fuel pump on it....pump lines seem correct on pump.still can"t get any gas up the fuel bowl....ihave used starter fliud to no avail to get the car started....any suggestions
MALIBU not getting gas up to my holley carb..
- Thread starter blu402mally
- Start date
Well you can try and prime the pump...try sucking ok use a vacume cleaner ..ect on the fuel line somewhere near the carb connection...use a peice of 3/8: gas neoprene hose ect to push onto fuel line okay the idea is to draw fuel through the pump and out if the fuel line there by wetting the holly pumps internal valves and then quickly reconnect the line back to the carb inlet once connected see if all is well (start engine ) if your pump is now pumping fine
If not 2 conditions come too mind a pinhole in the fuel line (or connection leak) or god forbid a defective pump..that's about as definitive a guess as practical....as a final experiment hook the holly inlet hose to a can of gas set near the floor but close to the pump use a peice of copper or neoprene hose to fit into said gas can be certain it reaches the gas within can if you run this way somethings wrong on the lines or pickup tube sock ect ...these simple things can be annoying but you will finger it out just keep going over yhe ground I mentioned how"....
If not 2 conditions come too mind a pinhole in the fuel line (or connection leak) or god forbid a defective pump..that's about as definitive a guess as practical....as a final experiment hook the holly inlet hose to a can of gas set near the floor but close to the pump use a peice of copper or neoprene hose to fit into said gas can be certain it reaches the gas within can if you run this way somethings wrong on the lines or pickup tube sock ect ...these simple things can be annoying but you will finger it out just keep going over yhe ground I mentioned how"....
x2.
Hose from the pump disconnected from the carb. Crank it over to see if your pulling fuel from the tank.
If not?
Check connections @ the tank. Drop the tank & verify the rubber hoses that connect the hardlines out of the tank (sending unit) to the hard lines on the chassis are in good shape. Cracks in these hoses can prevent the pump from actually pulling the fuel past that point because it will suck in air. It's common they aren't addressed & the ethanol in the fuel these days does a number on them.
If those lines are good, remove the gas cap & try again. If the tank isn't venting properly, it can cause a vacuum situation during these hotter months.
Start w/these steps & let us know the results.
Hose from the pump disconnected from the carb. Crank it over to see if your pulling fuel from the tank.
If not?
Check connections @ the tank. Drop the tank & verify the rubber hoses that connect the hardlines out of the tank (sending unit) to the hard lines on the chassis are in good shape. Cracks in these hoses can prevent the pump from actually pulling the fuel past that point because it will suck in air. It's common they aren't addressed & the ethanol in the fuel these days does a number on them.
If those lines are good, remove the gas cap & try again. If the tank isn't venting properly, it can cause a vacuum situation during these hotter months.
Start w/these steps & let us know the results.
The mechanical pump doesn't care if it has fuel to pump or not for a couple of minutes. It's going to do what it's going to do. If it's a priming issue, there's a couple of things you can do that is minimially invasive.
If you know the fuel suction line is clear, then take a plastic syringe (without a needle) and suck up a little gas and fill your primary carb bowl with gas through the primary bowl vent tube on the carb. Believe me, it works. I have done it. Don't go crazy, you just need enough to fill the bowl part way to get the engine going. You don't want to flood it. On a holley, you can remove the bowl side float level screws for when setting the floats, put enough fuel in to fill it to the screw holes to get an idea how much to fill. Then you can put the screws back in. You may need to do this a couple few times but it will allow the engine to start normally and run on its own until it pulls fuel into the line by itself. It WILL do it if the line is clear and fuel is in the tank.
If you suspect there may be some pluggage in the line back to the tank, you can, as mentioned, pull the fuel line from the suction side of the pump. Is the hose wet with fuel or fuel draining out? If so, it's probably getting fuel and the problem might be in the pump itself. If not, you can do a couple of things. Assuming you have a 2 tube sender on a stock tank and an air compressor, you can remove the fuel tank cap, use VERY LIGHT air pressure on the disconnected suction line at the pump and puff air back through the fuel line. Have someone back at the tank listen for bubbling. If you hear bubbling and/or venting of air from the neck, you have a clear line. Then, reverse the procedure to prime the line. Again, light and slow with the pressure. You won't need much. You don't want to blow off the fuel sock or pop a hose by going crazy with air pressure. Cap off the canister vent line from the tank, and slowly and lightly pressurize the tank from the neck side and have someone with a catch can at the suction line of the pump. When fuel pours out, stop and reconnect line to pump. Check under the car to ensure there are no other leaks. Fix any if there.
Good luck.
If you know the fuel suction line is clear, then take a plastic syringe (without a needle) and suck up a little gas and fill your primary carb bowl with gas through the primary bowl vent tube on the carb. Believe me, it works. I have done it. Don't go crazy, you just need enough to fill the bowl part way to get the engine going. You don't want to flood it. On a holley, you can remove the bowl side float level screws for when setting the floats, put enough fuel in to fill it to the screw holes to get an idea how much to fill. Then you can put the screws back in. You may need to do this a couple few times but it will allow the engine to start normally and run on its own until it pulls fuel into the line by itself. It WILL do it if the line is clear and fuel is in the tank.
If you suspect there may be some pluggage in the line back to the tank, you can, as mentioned, pull the fuel line from the suction side of the pump. Is the hose wet with fuel or fuel draining out? If so, it's probably getting fuel and the problem might be in the pump itself. If not, you can do a couple of things. Assuming you have a 2 tube sender on a stock tank and an air compressor, you can remove the fuel tank cap, use VERY LIGHT air pressure on the disconnected suction line at the pump and puff air back through the fuel line. Have someone back at the tank listen for bubbling. If you hear bubbling and/or venting of air from the neck, you have a clear line. Then, reverse the procedure to prime the line. Again, light and slow with the pressure. You won't need much. You don't want to blow off the fuel sock or pop a hose by going crazy with air pressure. Cap off the canister vent line from the tank, and slowly and lightly pressurize the tank from the neck side and have someone with a catch can at the suction line of the pump. When fuel pours out, stop and reconnect line to pump. Check under the car to ensure there are no other leaks. Fix any if there.
Good luck.
Just because the pump is new and happens to fit the motor doesn't necessarily mean it is the right pump. Did you happen to visibly compare your new unit with what came out of the motor? The pump actuating arms have been known to change shape and curve depending on application.
The other thing is that, during the install, did you happen to get the actuating arm lined up correctly with the pump plunger shaft that gets slid back and forth by the cam to depress and release the pump arm? If that shaft dropped while you were trying to stuff the pump in then the pump isn't pumping.
The trick for dealing with that shaft is to take a good look at the front of the motor down below the water pump where you can see the outline of the passage through which that shaft moves back and forth. The passage has a bolt screwed into it that seems to be doing nothing, What it does is to provide access to the shaft for the express purpose of using a slightly longer bolt that, when threaded in, will bump against the shaft and pin it in place. If, with the pump dismounted, you reach around into the pump cavity and use a finger or drift punch to push the shaft as far towards the cam as it will easily go, and then while holding it there, screw that longer bolt down until it barely just touches the shaft and pins it into place; very, very gently on that bolt, hand tight only! the shaft will stay up and out of the way while you insert the pump back into position and fasten it down. Once you have it locked into place, remember to remove that bolt, allowing the shaft to drop, and return the shorter bolt back into the boss. Failure to re-install the short bolt will result in an oily pissing mess as oil from the cam will find its way down the shaft and out the hole.
As has been pointed out above, it couild just be a case of the pump needing to prime itself and requiring that the engine crank over for a few revolutions to give the pump time to catch up. And I agree that pulling the pump to carburetor section of the fuel line and cranking the engine for a couple of turns to see if the pump is getting and delivering gas is a useful, quick, dirty method of learning whether or not it is the pump or something else.
Nick
The other thing is that, during the install, did you happen to get the actuating arm lined up correctly with the pump plunger shaft that gets slid back and forth by the cam to depress and release the pump arm? If that shaft dropped while you were trying to stuff the pump in then the pump isn't pumping.
The trick for dealing with that shaft is to take a good look at the front of the motor down below the water pump where you can see the outline of the passage through which that shaft moves back and forth. The passage has a bolt screwed into it that seems to be doing nothing, What it does is to provide access to the shaft for the express purpose of using a slightly longer bolt that, when threaded in, will bump against the shaft and pin it in place. If, with the pump dismounted, you reach around into the pump cavity and use a finger or drift punch to push the shaft as far towards the cam as it will easily go, and then while holding it there, screw that longer bolt down until it barely just touches the shaft and pins it into place; very, very gently on that bolt, hand tight only! the shaft will stay up and out of the way while you insert the pump back into position and fasten it down. Once you have it locked into place, remember to remove that bolt, allowing the shaft to drop, and return the shorter bolt back into the boss. Failure to re-install the short bolt will result in an oily pissing mess as oil from the cam will find its way down the shaft and out the hole.
As has been pointed out above, it couild just be a case of the pump needing to prime itself and requiring that the engine crank over for a few revolutions to give the pump time to catch up. And I agree that pulling the pump to carburetor section of the fuel line and cranking the engine for a couple of turns to see if the pump is getting and delivering gas is a useful, quick, dirty method of learning whether or not it is the pump or something else.
Nick
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