71-302 starts then dies

[71Mountain302]

I have a 71 w/ 302 it has started and ran great until I didn't start it for 3 days. I had to put a little gas in the carbs a few times before it would start AND stay running and let me tell you it blew out a ton of black, old burnt gas. I drove it around and it ran great, but now I find myself in the same situation, but can't get it started? Can anyone lead me in the right direction. Thanks!

 

[Bully Bob]

Hi 71.., wellcome..!  

Usually, in these cases, it's the accelarator pump.  With air filter off, work the throttle by hand

while looking down the throat of the carb.

You should see a stream of gas shoot out & down into the intake.

However.., did you mean "carbs" or  just 1 carb..?

RU saying it won't start now with gas dribbled in..?  Automatic choke or manual..??

 

[71Mountain302]

Sorry, new to this! It's 1 carb. When I put a little gas in, it starts right up and will idle for 10 or seconds then dies. I can rev it up but it will eventually choke out. Thanks!

 

[71Mountain302]

Automatic

 

[Bully Bob]

Now that sounds like a fuel pump or stuck/plugged needle & seat

Did you try the squirt test..?

 

[71Mountain302]

Just did the squirt test, no gas coming in. It will only stay idle if I continue to drop gas in. It is a 4 barrel carb on an edelbrock. Can I access the needle and seat?

 

[Bully Bob]

 "It will only stay idle if I continue to drop gas in"

This is a sign of no fuel in the float bowl or, the jets are plugged.

(fuel not flowing from bowl thru carb & into intake manifold)

You can Google your carbs mfgr.  & have a look at the  drawings,  "blow-up" drawings, etc.

Do you know the make/model of your carb..?

And yes/no..,  getting to the needle & seat externally.  Again, depends on the make/model carb.

Needle/seat can get stuck or plugged with dirt.  It's easy to clear once accessed.

The float can stick in the "up" position.., not allowing fuel in. (via the needle & seat)

The other option is the fuel pump.

They "weep" fuel out the bottom when bad. (weep hole)

You can rent a fuel press. tester for free at auto parts store.

Are the gas valves in the "on" position..?  On the full tank position..?   Gas in tanks..? :-B

 

[71Mountain302]

I just went under the tank and cleaned the electric connection, squirted some gas in the carb and she fired up and is running. It is still odd that if I don't start it for few days it does this, so I'm assuming there might be an issue somewhere. I'll keep ya posted. Thanks for all your help, I'm a total rookie that shouldn't even have such a sick ride. Cheers!

 

[Bully Bob]

Don't sell yourself short... we all had to start somewhere..!

However, un-clear what wires/electrical connection you cleaned..?  

RU speaking about an electric fuel pump.., electric tank switching valve..?  :huh:

 

[Rons beast]

Hey 71,

Curious like Bully as to the elect. connections you cleaned.

Also if you have this problem when the rig sits it can be a weak fuel pump or a filter in the carb that allows the fuel to drain out when sitting.  OR the fuel is weeping out and into the manifold causing a rich condition until it's burned off.

Another possibility is the ethanol in the fuel has allowed a lot of water to be absorbed.  This causes a powdery corrosion that clogs a lot of tiny ports and jets in the carb.

You should look at the fuel filter and replace if any signs of this is present, and run a can of Seafoam in the tank with 1/2 tank of fresh fuel.

I have this kind of issue with my SL and Lincoln when I don't drive them often. Actually had to recently replace one of the fuel pumps in my SL. It was ruined by the ethanol absorbing water and then sitting in the lower fuel pump that hangs under the tank. Water is heaver than gas and will sink to the lowest level. Then corrode whatever it sits in. 

Keep us informed as to your situation.

Good Luck