Starting Issue. Lack of fuel

[Bjmtexas]

I have a 70 challenger 340 with 6-pak. Recently changed the thermostat housing and battery cable. I started the engine and it did great. Turned it off and then tried to start it again and it would not start.

Seemed to be not getting any fuel. I added a little gas through the carb and it fired up. Remains running but as soon as let up on the gas peddle it dies and then does the same thing.

Suggestions/Help/Advise is appreciated.

Thanks

 

[Chryco Psycho]

Make sure the accelerator pump circuit is working so you should see a spray of fuel into the venturi of the carb as the throttle is opened if not you need to figure out why it is not working , it is easy to remove the center carb if you remove the rear carb first .
The other thing that will help is if the center heat cross over port is blocked off so the exhaust gas will not over heat the intake & evaporate the fuel in the carbs so the carbs have to refill before starting again .

 

[NoCar340]

Disconnect the pump-to-carb line near the pump and run a hose to a gas can. Have someone crank the engine while you watch the hose outlet. If you're only getting dribbles, there's your problem. The engine will idle nearly on fumes, but without sufficient fuel to fill the accelerator pump completely it'll die the second you crack the throttle.

Why do these things seem to always happen coincidentally after other, completely unrelated, things we've done? "I finally got new tires... and now my headlights don't work!"

 

[Chryco Psycho]

Check the float level in the carb also .

 

[fasjac]

Strange how things just happen. Anything mechanical is subject to failure without notice. Was it running fine prior to the T-stat housing replacement and battery cable?

 

[moparleo]

For safety sake, instead of "dribbling fuel" down the carb, which if spilled can cause a fire. Try using a squeeze bottle with the proper sized fuel line to fit over the vent tubes and fill the float bowls that way. Then you can use the accelerator pump to spray the proper amount of fuel into the carb throat. If the pump doesn't work, there is part of the problem.
Also do any fuel work outside of the garage in case of fire. Always have the proper fire extinguisher handy.

 

[Bjmtexas]

Strange how things just happen. Anything mechanical is subject to failure without notice. Was it running fine prior to the T-stat housing replacement and battery cable?

Yes it was all good. After hooked up the radiator hose it started great. no issue. Ran it for about 5 minutes - it idled fine. killed it to check for leaks and then put the breather cover back on. Did the restart and it would not fire up. did that for a bit then improvised with the fuel .

 

[Bjmtexas]

For safety sake, instead of "dribbling fuel" down the carb, which if spilled can cause a fire. Try using a squeeze bottle with the proper sized fuel line to fit over the vent tubes and fill the float bowls that way. Then you can use the accelerator pump to spray the proper amount of fuel into the carb throat. If the pump doesn't work, there is part of the problem.
Also do any fuel work outside of the garage in case of fire. Always have the proper fire extinguisher handy.

Thanks - will keep checking to see what is the issue.

 

[Bjmtexas]

Disconnect the pump-to-carb line near the pump and run a hose to a gas can. Have someone crank the engine while you watch the hose outlet. If you're only getting dribbles, there's your problem. The engine will idle nearly on fumes, but without sufficient fuel to fill the accelerator pump completely it'll die the second you crack the throttle.

Why do these things seem to always happen coincidentally after other, completely unrelated, things we've done? "I finally got new tires... and now my headlights don't work!"

Thanks --- The to do list is getting longer. You are right - sometimes with these old cars it make you think there are gremlins just running around doing stuff to give us grief. LOL

 

[Bjmtexas]

Make sure the accelerator pump circuit is working so you should see a spray of fuel into the venturi of the carb as the throttle is opened if not you need to figure out why it is not working , it is easy to remove the center carb if you remove the rear carb first .
The other thing that will help is if the center heat cross over port is blocked off so the exhaust gas will not over heat the intake & evaporate the fuel in the carbs so the carbs have to refill before starting again .

Thanks for the advice. Looking for good diagrams now to make sure what I am looking at.

 

[brotow]

For safety sake, instead of "dribbling fuel" down the carb, which if spilled can cause a fire. Try using a squeeze bottle with the proper sized fuel line to fit over the vent tubes and fill the float bowls that way. Then you can use the accelerator pump to spray the proper amount of fuel into the carb throat. If the pump doesn't work, there is part of the problem.
Also do any fuel work outside of the garage in case of fire. Always have the proper fire extinguisher handy.

NoCar340 said: " Disconnect the pump-to-carb line near the pump and run a hose to a gas can. Have someone crank the engine while you watch the hose outlet. If you're only getting dribbles, there's your problem. "

 

[Bjmtexas]

Thanks for the suggestion. Its on my todo list.

 

[moparleo]

The "there's your problem" just means no fuel past the pump. Could be bad pump diaphragm, eccentric is loose/off," had that happen to me) leak in fuel line, sucking air some where between the tank pickup and the pump. Plugged sending unit strainer. To test that you could run a line from a gas acan to the inlet side of the pump. Disconnect and ground the coil wire if you try this method. ...