1968 Dart Fuel Issues

[KCBones]

I went to start my Dart yesterday to drive it to a space where I'm going to be working on it. It has been sitting for a few weeks so I expected a cold start. It cranked well, battery was strong but I was not getting fuel to the carb. I'm getting good spark and it fired briefly with starting fluid but the carb was dry. No fuel in the fuel filter either. I was just going to replace the fuel pump (stock mechanical pump) and see if that's the problem but may need to order one. Many of the auto parts stores around me don't seem to keep stuff for old cars in stock. Is this the likely culprit or is there something else that I could also check?

 

[toolmanmike]

I went to start my Dart yesterday to drive it to a space where I'm going to be working on it. It has been sitting for a few weeks so I expected a cold start. It cranked well, battery was strong but I was not getting fuel to the carb. I'm getting good spark and it fired briefly with starting fluid but the carb was dry. No fuel in the fuel filter either. I was just going to replace the fuel pump (stock mechanical pump) and see if that's the problem but may need to order one. Many of the auto parts stores around me don't seem to keep stuff for old cars in stock. Is this the likely culprit or is there something else that I could also check?

It might be the check valve in the pump but probably not. More often than not it is simply fuel evaporation. Many here have installed a small electric pump back at the tank powered by a momentary contact switch to "prime" the system. That works well.

 

[toolmanmike]

Electric primer pump for fuel

I know I have read of a electric priming pump that you guys have used but I can't find the model or number. Help me out guys. this is a plunger type and I don't know how easily fuel from the mechanical pump would pull through. It should be rotary vane pump I think. Thanks Universal Standard...

www.forabodiesonly.com

 

[Dana67Dart]

Before you start throwing parts at it.

DISCLAIMER...

BE SAFE, GAS FUMES CAN KILL YOU.

Check that you have fuel in the tank, a flash light aimed down the filler tube will let you see.

Disconnect the fuel hose from the fuel filter to the carb and hook a hose to filter side it. Put the hose in to a sutible container and crank the engine. Do you have fuel from the fuel pump through the fuel filter?

With the tube attached as above, If you put a piece of tubing in a gas can and hook it to the fuel pump inlet do you get fuel through the fuel line and filter while cranking.

Other possible causes to your problem
Fuel pump escentric fell off
A stuck float
Clogged tubes or hoses
Clogged intank filter sock
Clogged tank vent
Empty tank

 

[KCBones]

Before you start throwing parts at it.

DISCLAIMER...

BE SAFE, GAS FUMES CAN KILL YOU.

Check that you have fuel in the tank, a flash light aimed down the filler tube will let you see.

Disconnect the fuel hose from the fuel filter to the carb and hook a hose to filter side it. Put the hose in to a sutible container and crank the engine. Do you have fuel from the fuel pump through the fuel filter?

With the tube attached as above, If you put a piece of tubing in a gas can and hook it to the fuel pump inlet do you get fuel through the fuel line and filter while cranking.

Other possible causes to your problem
Fuel pump escentric fell off
A stuck float
Clogged tubes or hoses
Clogged intank filter sock
Clogged tank vent
Empty tank

I put a couple gallons of fuel in it to make sure it wasn't empty, also disconnected the inlet to the fuel filter, put that end of the fuel line in a water bottle (all I had at hand) and cranked the engine a good bit. I got maybe 1/3 oz of fuel, not a lot but I wasn't really sure how much I should see. I took the filter apart and cleaned it (one of those sight glass types) and cranked some more. I'm not getting fuel into the filter, I would think that sight glass should fill up. The fuel tank was replaced within the past year. If the eccentric fell off, that looks like a bit more work to get to than the fuel pump. Thanks for the suggestions, gives me a place to start looking.

 

[67Dart273]

Go over to MyMopar and download your self a free shop manual.

You say you disconnected the filter.........that should be on the OUTPUT of the pump. What if the problem is BEFORE the pump?

 

[KCBones]

Go over to MyMopar and download your self a free shop manual.

You say you disconnected the filter.........that should be on the OUTPUT of the pump. What if the problem is BEFORE the pump?

I disconnected on the inlet side of the filter, outlet side of the pump. If the problem is before the pump, I'll have to figure something else out. I don't have compressed air to blow out any lines.

Are you saying to disconnect the inlet side of the pump and see if I am getting fuel from the tank to the pump by gravity flow?

 

[Murray]

Disconnect inlet side of pump and attach hose to bottle of gas. Spin motor. You should suck that gas empty rather quickly. If not, order that pump.

 

[Dana67Dart]

Go back and read post 4.

You do not need compressed air, your lungs will provide enough pressure to see if the lines are blocked.

 

[Dana67Dart]

. I got maybe 1/3 oz of fuel

You should get 1 qt of fuel in 1 minute or less @500 rpm

As 67dart273 mentioned get a free service manual, it's all right there.

This is from 67 manual. Most likely same section and page in 68.

 

[Dana67Dart]

Disconnect inlet side of pump and attach hose to bottle of gas. Spin motor. You should suck that gas empty rather quickly. If not, order that pump

Or pull the pump and use a flashlight to be sure the escentric is still in place.

You will have to pull the pump to replace it anyway.


I would still do much more testing and investigating before replacing parts

 

[KCBones]

Disconnect inlet side of pump and attach hose to bottle of gas. Spin motor. You should suck that gas empty rather quickly. If not, order that pump.

I see what you’re saying.

I was trying to reply to this while I was driving, not really a good idea. I'm back at my desk now. I see what you mean, I'll check the pump first before I try to replace it. I actually went to a nearby auto parts store that had the pump in stock so now I have one to put on in case that test doesn't work out.
Thanks.

 

[67Dart273]

I disconnected on the inlet side of the filter, outlet side of the pump. If the problem is before the pump, I'll have to figure something else out. I don't have compressed air to blow out any lines.

Are you saying to disconnect the inlet side of the pump and see if I am getting fuel from the tank to the pump by gravity flow?

That too. Attach a hose if you can and try and figure a way to apply either pressure or suction.