Hi All,
I"m having a hell of a time getting this 1980 Ford Bronco with 351m running.

We bought it for $500, and it was supposed to run, but have a crack in the engine cradle where the TTB bolts up. Turns out we were never able to get it to run. I pour gas in carburetor, it will fire up pretty quickly. At one point, I had gas to the carburetor, but not sure if that stopped after a while. I pulled the top of the carburetor and found the bowl bone dry with stuck float. I cleaned and re-assembled the carburetor with rebuild gasket kit but when we went to start it, but now no gas to carb (this is what makes me think the gas stopped flowing to carb). OK Looks like the fuel pump. So I replace the fuel pump. Still nothing. I tried priming by pouring some gas in carb and letting it fire - still nothing. So I wonder if gas is getting to carb.
Check with vacuum pump and I have gas to the filter.
Check inlet to fuel pump with vacuum pump and I"m seeing vacuum holding and not much gas. Figure this is it.
I blow out the line, and now I have good flow to fuel pump inlet with vacuum pump.

Try to fire it up, and still nothing. Could I have burnt up the pump trying to start it before I had good flow to the pump? Is this a bad (brand new) napa fuel pump?
I"m not sure what to do next. Any advice is appreciated.

 

Where is this pump mounted tank or motor?
If tank you have power to it when crankingWhat if you jump out the safety switches?

If on the motor where you trying to pull fuEl from tank or can and if tank how old is the fuel, all rubber lines been replaced yet?
Fuel in the tank?
Dave - - - -

 

What kind of fuel pump Elec or mech ? Make sure the fuel filter is not plugged before doing anything, it goes without saying the fuel filter should be on the pressure side of the fuel system. If the fuel filter checks out ok, remove the tank and lines from the equation. Disconnect the inlet for the pump and add a rubber hose to a container of gasoline then try it. if it works then you have either a plugged pick up and will have to drop the tank as it is likely full of crud.

With the inlet line in the bucket feeding the pump and still have no fuel remove the outlet line from the pump and used a piece of hose to feed it to a container you should have at close to and least 8 oz/250 ml or 1 cup of fuel within 10 seconds of cranking (with a fully charged battery) or running (elec pump).

 

It's a mechanical pump. The filter is not plugged, at least not yet. The tank and lines are old and had old gas (like varnish) sitting for some time. I syphened it out and put in new gas. There is a lot of crud (maybe rust particles) like dirt in the tank and links. Looks like PO replaced fuel lines, as they look new. Doing the vacuum test I found hard line from filter to pump inlet was restricted. I blew it out, and now it's OK/much better. I have fuel flowing freely from tank through the filter to fuel pump inlet with vacuum pump.

Sounds like next step is to remove both inlet and outlet of pump and use external inlet/outlet and see if pump is working. I'll try this after work and report back. Any other suggestions or ideas if it doesn't work?

 

If the fuel pump is not moving fuel with the lines disconnected either the fuel pump is faulty or it was installed incorrectly and is not riding on the cam lobe.

If the fuel pump is moving fuel Reconnect the inlet and test again if you have no fuel you will have to drop the tank and clean it out. You may also be collapsing the rubber fuel lines as they may have perished, Those old rubber fuel lines are not really ethanol compatible and will degrade.

Once you have cleaned the tank out and replaced the lines test to see if you now moving fuel.


If you are moving fuel through the pump with it connected to the tank, pull the fuel line from the carb disconnect the coil to minimize the chance of fire and put a rag under the fuel line at the carb and crank to double-check you are actually getting fuel to the carb
If you are getting fuel to the carb reattach the line and pull the top off the carb (it will run with the top of the carb to make sure it is actually moving fuel into the bowl. If you are not getting fuel into the bowl the needle and seat are plugged with debris, remove the needle and seat clear the debris reinstall and test for fuel flow. Then reassemble the carb.

 

Thanks for the help! When I gravity fed the pump, it took a very long time to prime (45 seconds or more of cranking in 5 second intervals), but it eventually started squirting fuel and after hooking up lines truck fired!
I'm really surprised it didn't prime from the tank, and that it took so long gravity feeding. That said, I think I'll prime the pump like this from now on, and then connect to the tank. Thanks for the suggestion - worked like a charm.

 

What you can also do is get a small squirt bottle and fill it with fuel. You can then pre-fill the carb with fuel through the fuel bowl vent shown in the picture below. It's the straight pipe(s) sticking up where the air cleaner fits on. Keep filling till you see fuel spilling into the engine, then stop. You can then start the engine and it will run for about a minute till it runs out of fuel. Most of the time it will keep running. If it still hasn't primed you can re-fill the carb again. This really saves your starter.