No fuel getting to my carb

[Sixt8Chrgr]

I have been chasing an issue where my car sits over night and it won't start until I prime the carb. Once it fires all good until the car sits. I thought the accelerator pump circuit was bad checked all of that. Have had the carb apart several times. Carb is dialed in. I installed a new Carter M6903. I am thinking either I have a bad fuel vapor canister or my fuel pump rod is worn out. My car is a 69 RT 440 restored, original drivetrain etc.

Any thoughts?


I apologize for the duplicate post, I could not find the original.

Lawrencer

[XH29N0G]

When you say prime the carburetor, you mean the fuel bowls are dry so you have add gas to it? or do you mean pump the gas pedal to squirt gas in via the accelerator pumps?

I have always had to do the last thing - pump the gas pedal to squirt gas in through the accelerator pump.  If the fuel bowls are dry, it is another issue. 

[b5blue]

How "fast" is it turning over? What carb. is it? If battery condition is kinda low or big draw when starting it could weaken spark and have low fuel delivery. Weak connections, old starter bushes and bad grounds can all hamper cold start.  

[Sixt8Chrgr]

I have to pour gas in the vents of the carb. The carb is the original Carter AVS.

Battery is new and the starter is newer. I suspect the turnover is normal. Wiring harness is new, grounds are clean no rust. There is no gas getting to the carb. Maybe the fuel filter/canister? Or the fuel pump rod? I will test the amount of fuel that is coming out of the pump when turning the engine over. See what I get.

[birdsandbees]

Someone's gotta ask... is there fuel in the tank? 

[c00nhunterjoe]

Sounds like classic fuel evaporation.  That is normal.

[b5blue]

  My 440 can sit for days but still lights up pronto. I've a Proform 750 vac. secondary w electric choke. New may not mean "good". I've had new cables AND wires with bad crimps that mocked other components being bad. (Starter-Alt.-regulator-ignition switch so on.)
  I do step on the accelerator before cranking, it releases the choke to position at cold start. Even with new fuels the car should start if it ran the day prior. 

[BSB67]

I suspect that you don't have a fuel not getting to the carb issue.  You have a fuel leaving the carb issue.

[Sixt8Chrgr]

Someone's gotta ask... is there fuel in the tank? 

Yes

[Sixt8Chrgr]

I suspect that you don't have a fuel not getting to the carb issue.  You have a fuel leaving the carb issue.

With the fuel line disconnected from the carb, and the end of the fuel line sitting in a jar. I turn over the engine with the coil wire disconnected, (engine spinning over) and I have NO fuel pumping into the carb from the fuel line.

That does not seem like evaporation, or a fuel leaving the carb issue to me? But maybe I am wrong?

[c00nhunterjoe]

If you "prime" the carb as you said, and then it runs all day, the pump is working. Crank the engine over longer with the line disconnected and see if fuel starts coming out. I would bet the fuel is either boiling out when sitting or draining out .

[Sixt8Chrgr]

If you "prime" the carb as you said, and then it runs all day, the pump is working. Crank the engine over longer with the line disconnected and see if fuel starts coming out. I would bet the fuel is either boiling out when sitting or draining out .

Yea, I agree with you. I was thinking that when I am starting the car the starter is not turning the engine over fast enough to pump the gas to the carb??

I have a phoenolic spacer under the carb for the heat.

How would it be draining out? It is not leaking on the intake. It is all dry and no gas smell overnight. 

Thanks for all the replies!!

[cdr]

If you "prime" the carb as you said, and then it runs all day, the pump is working. Crank the engine over longer with the line disconnected and see if fuel starts coming out. I would bet the fuel is either boiling out when sitting or draining out .

Yea, I agree with you. I was thinking that when I am starting the car the starter is not turning the engine over fast enough to pump the gas to the carb??

I have a phoenolic spacer under the carb for the heat.

How would it be draining out? It is not leaking on the intake. It is all dry and no gas smell overnight.  

Thanks for all the replies!!

Check the rubber hose at the tank for rotting, bend the rubber line looking for cracks, have seen this cause your problem many times. & while you are at it, check ALL the rubber lines.

[Sixt8Chrgr]

If you "prime" the carb as you said, and then it runs all day, the pump is working. Crank the engine over longer with the line disconnected and see if fuel starts coming out. I would bet the fuel is either boiling out when sitting or draining out .

Yea, I agree with you. I was thinking that when I am starting the car the starter is not turning the engine over fast enough to pump the gas to the carb??

I have a phoenolic spacer under the carb for the heat.

How would it be draining out? It is not leaking on the intake. It is all dry and no gas smell overnight.  

Thanks for all the replies!!

Check the rubber hose at the tank for rotting, bend the rubber line looking for cracks, have seen this cause your problem many times. & while you are at it, check ALL the rubber lines.

Thanks--those have all been replaced. Replaced the sending unit last night.

[BSB67]

If nothing is coming out of the fuel line, it could be the rod, as you mentioned.

But, if there was fuel in the carb the previous day when you ran it, where did the fuel in the carb go?  When you turn the key and the car starts like it should, it starts on the fuel stored in the carb, not what's coming from the pump.

[Sixt8Chrgr]

I drove the car to work yesterday. It sat in my parking garage for 8 hours. Got in it to go home and it struggled to start. But started. When it fires it acts like it is firing off of a little fuel until the rpm rises to a point that the carb is replenished with fuel then it idles smooth and nice. Drove it home put it in the garage. This morning tried it and would not start. Same issue, fuel starved. I am going to check the amount of girl coming out of the pump after 15 seconds of cranking and check the fuel pressure, per my engine builder. Will report back. Thanks!

[BSB67]

I think those are good things to check.

Considering how easy it is to change the rod, you might consider just doing that too.

[XH29N0G]

I drove the car to work yesterday. It sat in my parking garage for 8 hours. Got in it to go home and it struggled to start. But started. When it fires it acts like it is firing off of a little fuel until the rpm rises to a point that the carb is replenished with fuel then it idles smooth and nice. Drove it home put it in the garage. This morning tried it and would not start. Same issue, fuel starved. I am going to check the amount of girl coming out of the pump after 15 seconds of cranking and check the fuel pressure, per my engine builder. Will report back. Thanks!

I assume you dictated that last message.  I had the fuel pushrod go and the symptom was that it would starve of fuel when running, but not when I shut it down.  It isn't a difficult thing to change, but I think it is a puzzle as to why the fuel would leave the carburetor.  The common things I can think of would be leaking and evaporation, but you seem to have both of those covered.  I don't know the geometry of the system, but I would think it would be difficult to siphon out through the inlet hose because when the fuel level dropped a little it would break the siphon.  Maybe someone else knows otherwise.

I wonder if it is a very very slow leak (so you aren't noticing it except after the carb sits for 8 hours or more).

[cdr]

Check the vent to make sure the tank IS venting

[Alaskan_TA]

Ethanol fuels evaporate faster under heat than gasoline does.

A dry fuel bowl is normal for some cars, one of mine does it too.

Even quicker though, I can fill the bowl, drive an hour or two to a car show where it sits for 1-4 hours & I have to fill the bowl again to get it going.

I use an old mustard bottle with a squirt cap, it works great.

[Sixt8Chrgr]

I drove the car to work yesterday. It sat in my parking garage for 8 hours. Got in it to go home and it struggled to start. But started. When it fires it acts like it is firing off of a little fuel until the rpm rises to a point that the carb is replenished with fuel then it idles smooth and nice. Drove it home put it in the garage. This morning tried it and would not start. Same issue, fuel starved. I am going to check the amount of girl coming out of the pump after 15 seconds of cranking and check the fuel pressure, per my engine builder. Will report back. Thanks!

I assume you dictated that last message.  I had the fuel pushrod go and the symptom was that it would starve of fuel when running, but not when I shut it down.  It isn't a difficult thing to change, but I think it is a puzzle as to why the fuel would leave the carburetor.  The common things I can think of would be leaking and evaporation, but you seem to have both of those covered.  I don't know the geometry of the system, but I would think it would be difficult to siphon out through the inlet hose because when the fuel level dropped a little it would break the siphon.  Maybe someone else knows otherwise.

I wonder if it is a very very slow leak (so you aren't noticing it except after the carb sits for 8 hours or more).

Looks like I dictated it for sure, awful grammar.
After the car sits for a long time there is evaporation, for sure. I get a little stream of fuel from the accelerator pump circuit after the first pump of the gas pedal, but nothing after that because the bowl is too low to fill the accelerator pump bore, and the fuel pump is not refilling the bowls. As a side note, there is a check valve between the fuel bowl and the accelerator pump bore that allows fuel to flow into the bore from the bowl. I have cleaned it and tests ok.
I have mentioned in another post that I read that the fuel/vapor canisters have been known to impede fuel flow. I want to first test the fuel pump flow and pressure prior to just removing and replacing that part. I just need time to work on it but work gets in the way.
Thanks for the replies.

[Sixt8Chrgr]

If nothing is coming out of the fuel line, it could be the rod, as you mentioned.

But, if there was fuel in the carb the previous day when you ran it, where did the fuel in the carb go?  When you turn the key and the car starts like it should, it starts on the fuel stored in the carb, not what's coming from the pump.

I agree. Have to be through evaporation I guess?

[Sixt8Chrgr]

Check the vent to make sure the tank IS venting

What is a good way to do this? When I fill up my tank I can only get about 12 gallons in the tank I am assuming due to a trapped air bubble. I had this same problem with my boat and stuck an air hose in the tank and blew air in the tank which worked. I tried the same thing in my Charger tank and really not sure it worked. So what should I do to confirm my tank is vented?

[303 Mopar]

Check the vent to make sure the tank IS venting

What is a good way to do this? When I fill up my tank I can only get about 12 gallons in the tank I am assuming due to a trapped air bubble. I had this same problem with my boat and stuck an air hose in the tank and blew air in the tank which worked. I tried the same thing in my Charger tank and really not sure it worked. So what should I do to confirm my tank is vented?

Drive around for a while, and listen when you remove the gas cap. If you hear a "swoosh" sound, chances are it is not vented.  Also, the fact that you only get 12 gal when empty is a good sign it is not vented. Do you have a vent line or at least a vented gas cap?

[cdr]

Check the vent to make sure the tank IS venting

What is a good way to do this? When I fill up my tank I can only get about 12 gallons in the tank I am assuming due to a trapped air bubble. I had this same problem with my boat and stuck an air hose in the tank and blew air in the tank which worked. I tried the same thing in my Charger tank and really not sure it worked. So what should I do to confirm my tank is vented?

The little steel line that hooks to the filler neck inside the trunk, make sure it is not plugged up, but where that vent is would not affect filling up the tank, that is another issue. I do have a fix for that.