Carburetor vs fuel pump? It'll crank but won't fire unless I put some gas in the carburetor! What to do first?

If your fuel pump is in the gas tank the fuel pump is cooled and lubricated by the gas. If you run out of gas and keep trying to start it many times you can damage the fuel pump. If you have a older car you can try putting a little gas in the carburetor and see if it cranks, if it cranks with gas in carburetor you know it is a lack of fuel problem. You might try spraying starting fluid in air filter but to much can damage your engine. Some links below may provide some help.
https://www.yourmechanic.com/question/car-won-t-start-after-it-ran-out-of-gas-and-was-filled-again
https://www.bimmerforums.com/forum/showthread.php?1881026-Ran-out-of-fuel-now-won-t-start-please-help!
Your vehicle fuel pump can run and pump gas but depending on your vehicle you may not have enough fuel pressure to run. I would check your fuel pump fuse and relay and fuel inertia switch/fuel pump kill switch if you have one. I do not know why running out of gas would cause them to fail but it is something to check.

No fuel going to carburetor ??? Your vehicle should have fuel injection ,not a carburetor . Is the SECURITY light lit on the instrument cluster ? Anti-theft system will keep fuel injectors from firing , or if there isn't any spark at the spark plugs the crankshaft position sensor could be bad . The PCM - engine computer will energize the fuel pump relay for two seconds to prim the fuel lines an the fuel rail for the injectors . After that it won't unless the engine is cranking over , an the PCM see's an input from the crankshaft position sensor . Your best , take it to a qualified repair shop.

Fuel pump. They are mechanical and just die sometimes.

Fuel pump could be bad. Newer car? Could be security. Year make and model helps.

Normally, you wouldn't need to do this to get the engine started. If you have a mechanical fuel pump ion the engine, just cranking the engine over should cause the pump to push gas into the carburetor. And if an electric pump, it should come on with the key in on.

But to prime, pour a small amount of gas down the throat of the carb, and crank. As the engine fires and runs, the pump should begin working and pushing fuel into the carb.

Nobody has messed around with the ignition timing in any way?



If it has stood for a long time(i.e years..) the fuel may have degraded to the point that it\'s useless.



The carbs will smell of fuel, but are you sure that fuel is being pumped to them in sufficient quantity? Try disconnecting a fuel line, crank the engine a few revolutions to see if fuel is pumped out.



Try gravity feeding the carbs. Use a can of fuel connected to the carbs, held above the engine. Get somebody to crank the engine and see if it fires up. If the engine fires up, suspect the fuel pump.. or fuel lines.



An air leak can also cause non-starting. The usual cause is the inlet manifold gasket. Any air leaking through the gasket can cause your non-starting problem. Go back and check that no dirt has been picked up by the gasket before you fitted it/it hasn\'t been ripped. Check that the inlet manifold has been correctly tightened.



It doesn\'t sound as though you have much of a problem .. more of a \'niggle\'.

The link is for Zenith carburettors:



Zenith carburetor Google Search

A car needs 3 things to start. Air, fuel, and spark. Check that it can get air by removing the air cleaner and inspecting it. Leave the air cleaner off for now. Try a squirt of starting fluid into the carburetor (not a lot mind you, just a quick squirt). Be prepared to quench a flame if the engine backfires through the carburetor (have a wet towel handy). Crank the engine. If it fires, you have spark. If it does not fire, you have ignition problems. If it fires and stalls out quickly, you have fuel problems.
For fuel problems: Be sure you have gas! (I know it is obvious, but check the tank!). If the car has not been used for awhile, the gas may have gummed up the carburetor. While it is possible for the weekend mechanic to take a carburetor apart and clean it, it is probably best left to a professional mechanic. Verify that you are getting gas to the carburetor by detaching the rubber gasoline hose at the carburetor. Most cars today have electric fuel pumps, so turning on the ignition should result in a stream of fuel from the gasoline hose. If not, crank the engine and see if a mechanical fuel pump moves the gas. If you get no gas, find out why or your car will never start. If you get gas, the carb is probably gummed up. It is best to conduct this last test into a mason jar to catch the gas, and it is best to postpone the cigarette break until after the test is complete.
If you suspect the ignition, pull a spark plug. It should look clean and whitish to light coffee color. If it is filled with carbon and oil, you have other engine problems. You can look for an ignition spark by laying the plug case against the engine while it is attached to the distributor wire. Crank the engine and you should see a spark jump the gap at the spark plug tip. This spark is often small and hard to see in sunlight. Do not perform the spark plug test in the temporal vicinity of the fuel test. A hot spark with gasoline nearby is dangerous.

A car that turns over means that at least the battery is good. Try next to insure it has air, gas, and spark.

That sounds like the fuel pump may have lost it's prime. Does it have fuel injection, or a carburetor on the engine? How much gas was in the tank while it was parked on an incline? Have you tried any starting fluid sprayed into the air intake hose, toward the engine? Warning! Don't use much starting fluid! Perhaps a one or two second burst, and have someone crank it immediately after you have stepped back at least 6 feet from the engine. If it fires, then it is definitely a fuel delivery problem! But it won't run long like that unless the fuel pump starts working again ... which is most likely when the engine is cold!

You need to pull the fuel line from the carburetor and watch for fuel flow as someone cranks over the engine. Sounds as though the pump has gone out or possibly just blown a fuse.

you might have a calapsed fuel lint disconect it from the motor and have some one try to turn it over see if any gas comes outif this does not work you will need to replace fuel lines