having trouble getting fuel from tank to fuel pump

[66" bronco]

I have a 66 bronco and I have replaced the fuel pump. I am having trouble getting gas from tank to fuel pump. I have undone the line from fuel pump to carb to see if it was getting gas but it wont. any recommendations or what is possibly causing this problem. Thanks

 

[Broncobowsher]

Is this a V8?
Did you get the fuel pump arm UNDER the eccentric on the front of the cam? Generally that makes installing it a pain as you have to compress the stiff spring on the fuel pump by hand as you get the bolts started. If the fuel pump bolted up easy you probably didn't get it bolted on right.

 

[broncojo]

Were you getting fuel before the pump was changed or is that why you changed the pump?

 

[Jerseydevil]

Why did you replace the old pump? Ever inspect your tank, or the strainer on the in tank pick up tube? If that's clogged, you won't get fuel even with a new pump. I am hoping it's just a matter of getting the pump on properly; like broncobosher described. But if not, see if you get fuel to the pump by removing the line at the pump, and putting compressed air into the tank. This should force gasoline out, and let you know the strainer or line aren't clogged. take it slow, and be prepared. Maybe put the open end in a jar to catch the gas.

 

[Broncobowsher]

To add to potential problems...
Selector valve (multi-tank?)
Any pin hole in the suction line will keep the pump from pulling gas from the tank. Only takes the slightest air leak into the fuel line to allow enough air in that the pump can't suck. how small of a hole? Take a drinking straw and put a tiny pin hole in it and try to drink with it. You can ramp up your suction to try and pull more in. A cranking engine is barely pulling any vacuum. Your drinking straw is 12inches long, not 12 feet long as well.

I have had a few fuel pumps that were not happy trying to pump while dry. Get a little gas in them and the seals will now seal and it will start to pump. Also have primed the carb by filling the fuel bowl and run the engine off that long enough for the pump to pull a prime.

 

[66" bronco]

Thanks for all the input. Yeah this is the original straight six in the 66. I replaced the old pump due to it having a leak in the bottom and not pumping. When I started the restoration I had the tank boiled out and replaced the sending unit. The tank wasn't in that bad of shape but the sending unit needed replacing. I haven't replaced the plastic fuel line.

 

[Broncobowsher]

I don't know if you can put the fuel pump arm on the wrong side of the lobe on the I6 like you can with a V8. That is a well known V8 mistake.

 

[66" bronco]

yeah it will only go on one way with the straight six. I am wondering if the fuel line has a pin hole leak in it. my great grandpa bought this bronco new off the lot in 66 so it is all original uncut. the fuel line has never been replaced. the bronco had just been sitting in a shop untouched since 86. I put a new carb, changed fluids, and it cranked right up before I took parts off the motor to have powdercoated. first time I cranked it I ran it by a gas line in a gas can.

 

[PaveBronco]

Wow, that’s going to be a great tribute to you Great Grandpa. You could try disconnecting both ends of the main line and put some low pressure air through it. Make sure you do disconnect both ends, you don’t want to blow any crud into your tank or pump…If it was mine, I’d just replace all the fuel lines, cheap insurance and available, WH, TBP, Jeff’s, all have them.