Engine will not start after sitting a couple days

[1badchevy]

Hi
I have a 350 4bbl. w/ stock dual tanks
It starts up just fine if I do it daily but if I let it sit for a couple days even pumping the gas pedal doesn't start it, I have to dump some gas in the carb.
I want to learn how to work on my own truck but don't know where to start.
Thanks

[zieg85]

You may have a weak fuel pump that bleeds the fuel backwards after a while of sitting.  One of my trucks does the same thing.

[1badchevy]

You may have a weak fuel pump that bleeds the fuel backwards after a while of sitting.  One of my trucks does the same thing.

Thanks, that's where I was thinking of starting but wanted some advice from the forum first

[Stewart G Griffin]

Or the plugs on the bottom of the carb may be leaking.....

[1badchevy]

Or the plugs on the bottom of the carb may be leaking.....

Thanks, I will post the cause when I get it fixed.

[rich weyand]

Same thing here.  The fuel leaks back.  I crank the engine (no throttle) for about 10 seconds to pump the float bowls up.  Then I push the throttle to the floor and hold it there for a couple seconds, twice, then it will start on the first crank.

[ronmauer]

The Q-jet carb bowl only holds a small amount of gas. The gas evaporates in a few days so you have to fill the bowl again. I recommend crank it for 1-2 seconds and the fuel pump makes a stroke and the gas will start to flow. Let it sit for 5 seconds and then crank for 1-2 seconds(save the battery & starter) About 3 or 4 times you can pump it and it'll start if the fuel pump is OK and the accelerator pump is OK. The fuel pump can be OK but If the choke doesn't close and the accelerator pump doesn't work it may not start without pouring gas in the carb.

[Stewart G Griffin]

The Q-jet carb bowl only holds a small amount of gas. The gas evaporates in a few days so you have to fill the bowl again. I recommend crank it for 1-2 seconds and the fuel pump makes a stroke and the gas will start to flow. Let it sit for 5 seconds and then crank for 1-2 seconds(save the battery & starter) About 3 or 4 times you can pump it and it'll start if the fuel pump is OK and the accelerator pump is OK. The fuel pump can be OK but If the choke doesn't close and the accelerator pump doesn't work it may not start without pouring gas in the carb.

Actually, yeah, this too.

[blazer74]

Quad should fill up and start within 15 seconds or so with a good fuel pump.

Possible your needle is sticking when the bowl is dry.

[1badchevy]

Quad should fill up and start within 15 seconds or so with a good fuel pump.

Possible your needle is sticking when the bowl is dry.

I tried the suggestions on how to get it to start and it didn't work so I will take a look in the carb,  I have work on motorcycle carbs but never autos so this should be interesting.
Once I get this pickup started man it just purrs and starts with easy as long as I don't let it go for more than a couple days.
The pickup came off a huge ranch in southern New Mexico and is totally and I mean totally rust free, all the bolts came off so easy.

[blazer74]

Check u tube for videos on rebuilding the quad. Lots of info out there.
 

[blazer74]

R U putting fuel down the barrels of the carb or in the float bowl when it starts.

[1badchevy]

R U putting fuel down the barrels of the carb or in the float bowl when it starts.

down the barrels
thanks for the tip on Youtube

[bd]

More than likely the fuel bowl is draining past the fuel well plugs.  Fuel well plug repair kits are available, but provide marginal results.  For the best long-term results you will need to lightly seat, peen, burnish and epoxy the plugs.  Though pricey, the most durable epoxy for the purpose is Devcon Plastic Steel.  JB Weld will also work if the metal is properly prepped, but JB Weld doesn't provide the longevity of Devcon.  You should also install a pleated paper fuel filter that sports an integral check valve.  The check valve serves a dual purpose.  It prevents fuel in the tank and lines from draining through the carburetor in the event of a rollover, but also prevents overnight siphoning of fuel from the carburetor and lines back into the tank.  As before, Youtube the procedure for sealing QJ fuel well plugs.

[blazer74]

If your well plugs are leaking badly you will experience hot start problems as well as a quickly dry fuel bowl.

I install a well plug kit in my own carbs and still have a dry bowl after a few days from heat and today's Ethanol enhanced fuels.

Regardless, after a few days of sitting cranking  and several pumps of the pedal the carb should fill with fuel and start.

Otherwise it runs great, puzzles me.
If the accelerator pump in the carb was not working that would not be the case.

When you take the top off the carb don't miss the two screws inside below the choke flap.