Can;t get gas up to carb

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highwaystar

highwaystar

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I am looking for help. I have a new gas tank and a new sending unit and a new 3/8 fuel line. The only thing that is not new is the return line. The car ran when I had it hooked to a 2 gallon gas tank. Then I tryed to connect to the factory tank and nothing. I shot compressed air into tank and then had some gas come back and I put on the line and it brings a small amount to the fuel filter that I can see, but not enough to keep it running. I poured gas in the carb 8-10 times it would fire and then run out of gas????? This car has sat a long time, the return line the problem? or is it the Vans 3/8 sending unit I put in? Anybpody have experience with them?
any info would be helpful.
T.J.
 
Where did you connect the 2 gallon gas can, to the input of the mechanical pump? If yes, then sounds like you have a kinked line or problem with your new pickup. I had all new system from tank to carb (mechanical pump). All I did was filled the float bowls and fired the motor, mechanical pump pulled the gas from the tank and filled the carb within seconds.
 
Yeah, I had a 8 ft. 3/8 line from fuel pump directly to the 2 gallon gas tank. No kinks in line. it is a brand new fine line piece. sounds like the sending unit. HuH? the return line being plugged won't cause any problem, will it?
 
well I took a second look at the sending unit. I have the return line coming into the top of the tank and the gas line going into the sending unit, and then there is another line on the sending unit that has a cap on it. Is this for some kind of return line as well.? It has a plug on it right now that was leaking, probaly creating a vacumn leak. Is this the wrong sending unit for this application? I see them online with and without this line on the sending unit. My 72 scamp has just the one on the sending unit and vent on the top of the tank as well. I am working on a 72 Duster.
 
i just went through this with my dart, it say a better part of theyear. would run if i filled the bowls of the carb. if i pressurized the tank i could fill the carb but it just wouldnt pump. i pulled the carter pump apart and found nothing wrong but it still wouldnt pump fuel on the bench. took it apart and shot carb cleaner into the valves and blew them out. and it worked. the valves must have been stuck from sitting.
 
My sending unit has that extra line,it goes to the fuel canester.I just plug mine off.Check the rubber line from your sending unit to the steel line.
 
I believe the carb is alright, It ran well with the 2 gallon tank on the fender. I can see the fuel filter, just is not filling like it did with the line stuck in the 2 gallon tank. looks like i am going to have to pull the tank and sending unit. HaaHHHHH.
 
I talked to Van's yesterday. It is there new fuel tank and new sending unit. They had no answers for me. I checked the line again today, and there are no bends in it. The rubber line connecting the fuel tank to the line is brand new as is the 3/8 fuel line going to the front of the car. I can only imagine the new sending unit had some trash in it from the get go (brand new)?? I'm scratching my head on this one.
 
Try air through the line again, with cap off, 10 lbs,listen for the gurgle. Carefull of static spark, ground if you wana play it safe.Lastly I`d pull the S-unit and see if it`s clear. hope you don`t have a bunch of gas in there. Let us know what it was/is:clock:
 
Check your pick-up? Maybe theres something in the sock clogging it up? Hard to believe though if it's brand new...but stranger things have happened.
 
Are you sure the sending unit is not installed upside down?
Just gotta ask, stranger things have happened.
 
Hi Warwagons,
I thought the same thing, When I talked to the guy at Vans, He put one together at his shop, same gas tank same sending unit. He said it should be pointing up at the 12:00 position, and a little towards the 11:00. I checked mine after that and it is in the same position. Puzzling, I do remember it went in a little hard into the gas tank, had to push on the sending unit as I was putting on the lock ring. almost like it didn't fit well to begin with.
 
On the sending unit, the fuel line should be at 9:00 and the gauge wire directly across at 3:00 (on belly looking at tank). The float arm has a stop to bottom on. This will help placement in the tank. Hope this makes sence.
 
Beatnik said:
Check your pick-up? Maybe theres something in the sock clogging it up? Hard to believe though if it's brand new...but stranger things have happened.
Click to expand...
I read about this in a mopar magazine, that somehow it is possible for the filter on the end of the pickup tube to be pushed all the way to the end of the filter (the screened filter in the tank) and THAT plugs the line, they were saying that happens alot when installing a new sending units. give that a try....I know that means you have to drain the gas and remove the sending unit but.......
 
Well, I removed the sending unit. All was ok, blew air thru. It was fine. Blew air thru the fuel line, all ok. set vacumn pump on line drawed gas up to fuel pump. still not the greatest. fuel filter barely fills up. I believe the return line is plugged. I am going to look at that next. There is a rubber line under the passenger seat. that may be rotted or collapsed. i will keep everyone posted.
 
Does your Duster have California emissions ie charcoal canister etc?
You may have the wrong sending unit or a previouse owner may have bypassed the fuel routing(s).
Just a thought

highwaystar said:
well I took a second look at the sending unit. I have the return line coming into the top of the tank and the gas line going into the sending unit, and then there is another line on the sending unit that has a cap on it. Is this for some kind of return line as well.? It has a plug on it right now that was leaking, probaly creating a vacumn leak. Is this the wrong sending unit for this application? I see them online with and without this line on the sending unit. My 72 scamp has just the one on the sending unit and vent on the top of the tank as well. I am working on a 72 Duster.
Click to expand...
 
do you mean the vent line from the charcoal canister to the tank?
 
Yes I have a 1/4 line? coming from the front of the car into the top of the tank. I believe it did go into the charcoal cannister that I currently do not have. The line is just open at about where the fuel line ends, below the passenger side manifold. No cali. emmisions, just the one return (vent) line. Yes the vent line. If there is blockage there, that is probaly going to cause problems, right?
 
jamesdart said:
i just went through this with my dart, it say a better part of theyear. would run if i filled the bowls of the carb. if i pressurized the tank i could fill the carb but it just wouldnt pump. i pulled the carter pump apart and found nothing wrong but it still wouldnt pump fuel on the bench. took it apart and shot carb cleaner into the valves and blew them out. and it worked. the valves must have been stuck from sitting.
Click to expand...

i dont think its a good idea to use that as a vent into your engine compartment, but i doubt it is your problem. i still say its your pump. if a vent was your problem, you should be able to pull the fuel cap off and it will run fine.
 
Fuel pump >>> not enough suction ... and barely enough pushing ????
 
The tank must vent or there will be excessive vacuum. The pump will stuggle to pull fuel. I would not think the pump was bad as you indicated it works by bypassing the tank with a long hose.
Jamesdart is correct, take off the gas cap and try running it.



highwaystar said:
Yes I have a 1/4 line? coming from the front of the car into the top of the tank. I believe it did go into the charcoal cannister that I currently do not have. The line is just open at about where the fuel line ends, below the passenger side manifold. No cali. emmisions, just the one return (vent) line. Yes the vent line. If there is blockage there, that is probaly going to cause problems, right?
Click to expand...
 
Well this vent line is a 2 piece. I disconnected at about under the passenger seat, where the rubber line connected the 2 and it was clogged all the way to the front. I will give it a try over the weekend with the gas cap off and see how it works. It's funny to here I had a friend stop in and said both his 68 Cudas did the same. Seems like that would lean the motors out, when the carb is not getting the gas it needs. It may be a epidemic in these old cars. Everyone might want to check there vent lines.
 
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