Fuel delivery issues

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Dave Haertel

Dave Haertel

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So, 360 in my 71 Dart.

Replaced the sending unit, fuel tank and the fuel pump after finally straightening out my electrical ignition issue, wanting to clean up any lingering fuel issues but created a monster. Car will start and run with fuel in the carb but can't get the system to prime. Any tricks to getting it going again?

Was thinking there might be something in the steel line between the pump and the sending unit/tank but it was running right up until I shut it off to swap everything out so I really don't think there's anything there.

Something I'm missing?
 
Is there fuel in the tank? I know it is a dumb question but I have done dumber things,:rolleyes:

How many fuel lines does a 71 have? could you have hooked them up wrong? I know I know see end of question #1

If you think your issue is fuel pump not sucking fuel from tank do to dry lines you could disconnect the like into the pump and slightly pressurize the tank with compressed air, don't go overboard a few lbs should be enough to move the fuel. (USE EXCESSIVE CAUTION WITH FUEL AND VAPERS, a local guy blew up his garage with a portable heater and leaking fuel in his garage)
 
I put as much of a 5 gallon can in as I could get, so 4.5 gallons for sure. I did actually think twice when you suggested it though.

As for the pressurizing, I don't have a compressor, is there another way to pressurize it that you can think of?

I'm aiming to make this my driver and have it fully reliable, maybe I should replace the lines to be 100 percent sure everything is new. Not sure how bad of a job that is on this one.

Dana67Dart said:
Is there fuel in the tank? I know it is a dumb question but I have done dumber things,:rolleyes:

How many fuel lines does a 71 have? could you have hooked them up wrong? I know I know see end of question #1

If you think your issue is fuel pump not sucking fuel from tank do to dry lines you could disconnect the like into the pump and slightly pressurize the tank with compressed air, don't go overboard a few lbs should be enough to move the fuel. (USE EXCESSIVE CAUTION WITH FUEL AND VAPERS, a local guy blew up his garage with a portable heater and leaking fuel in his garage)
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Is your pickup tube reaching bottom of tank
 
Did your sender have a return line? Maybe your hooked up to that? I know my 68 dart I capped the return line as I wasn't using it. Just throwing idea's out there. Also make sure some how inlet outlet on fuel pump is correct . I somehow did that with my 440 motor.
 
Kendog 170 said:
Did your sender have a return line? Maybe your hooked up to that? I know my 68 dart I capped the return line as I wasn't using it. Just throwing idea's out there. Also make sure some how inlet outlet on fuel pump is correct . I somehow did that with my 440 motor.
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Thanks, this sending only has a supply, no return line on it. The pump itself has two different types for inlet and outlet. The outlet (going to the carb) is a hard line threaded that gets connected to rubber line to go to the carb, so those connections are correct as they can only go one way.

I think I’m going to pull the hard line off, make sure nothing is blocking that off somehow going to the carb. Then I’ll look at the supply line to see if there’s a crack or break somewhere stopping it from creating suction. So frustrating that it was working before I swapped this out.
 
Dave Haertel said:
Thanks, this sending only has a supply, no return line on it. The pump itself has two different types for inlet and outlet. The outlet (going to the carb) is a hard line threaded that gets connected to rubber line to go to the carb, so those connections are correct as they can only go one way.

I think I’m going to pull the hard line off, make sure nothing is blocking that off somehow going to the carb. Then I’ll look at the supply line to see if there’s a crack or break somewhere stopping it from creating suction. So frustrating that it was working before I swapped this out.
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WITH NO VENT ON THE TANK, ARE YOU SURE YOU`VE GOT A VENTED CAP ?
 
famous bob said:
WITH NO VENT ON THE TANK, ARE YOU SURE YOU`VE GOT A VENTED CAP ?
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Not sure how to tell, it's the same cap that worked right up until the swap. It has 4 additional connections/vent connections near the top of the tank under the filler tube which I think was part of the vapor canisters these used to run but have since been stripped out of this one. I would think those would help vent.
 
You can and I have done this before, remove your fuel pump hook it back to your gas line and physically move the pump lever. If you get no gas at this point, no gas reaching tank inlet screen, pin hole in the steel line, bad pump. If you have a gas filter between the steel line and the inlet side of your pump remove it.
 
Here is a description of how your 4 vent tank system was hooked up: Fixing 1970s Evaporation Control Systems

I'd replace the line from the tank as a 1st step. After 48 years, some internal scaly rust could have fallen in when you were working with it; you just don't know. One poster one FABO once reported finding a bug blocking the line LOL
 
nm9stheham said:
Here is a description of how your 4 vent tank system was hooked up: Fixing 1970s Evaporation Control Systems

I'd replace the line from the tank as a 1st step. After 48 years, some internal scaly rust could have fallen in when you were working with it; you just don't know. One poster one FABO once reported finding a bug blocking the line LOL
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Ok, really not enjoying thinking about bugs being trapped in the line while I'm working on it and running out of there when I disconnect them LOL. That is a good thought though, it is an older set of lines for sure, there could be any number of issues with them. I've never actually re-plumbed one of these, are the lines easily accessible in the frame rails or am I setting aside a couple of hours to fight with them?

Since the evap can was removed from the system, I hadn't hooked those lines back up to the tank, I assumed they were just cut somewhere up further and there wouldn't be a difference. I guess I can lower the tank and put them back on, but I'm not sure how much that matters.
 
I’m sure it was mentioned,but you can fill the carb through the carb vent, unhook the output of the fuel pump and put it in gas can. Start car which should run a bit, see what comes out of the pump. You can try and prime it this way, but leave the line connected. You may have to do it multiple times.
 
furrystump said:
I’m sure it was mentioned,but you can fill the carb through the carb vent, unhook the output of the fuel pump and put it in gas can. Start car which should run a bit, see what comes out of the pump. You can try and prime it this way, but leave the line connected. You may have to do it multiple times.
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That's an interesting thought. I was thinking of pulling the inlet line from the line to the back and dropping it in a gas can to see if it'll run from there but disconnecting the output and letting it run for a second or two should produce some fuel from the outlet side also if the fuel is coming up from the tank. Sounds like I have a few options to test with this evening when I get home.
 
Yes, you can run fuel from the pump into an open container; that is one test, and ought to show the line being fairly clear. But, realize that even if that works that a faulty pump may not pump properly into the back pressure that will build up when the carb is attached.

I think any bug in the line will be quite dead LOL

Replacing the line will take a few hours. IIRC, there are clips into the frame rails that may need to be renewed if you keep it original. Or you can make some other attachments.
 
Dave Haertel said:
Not sure how to tell, it's the same cap that worked right up until the swap. It has 4 additional connections/vent connections near the top of the tank under the filler tube which I think was part of the vapor canisters these used to run but have since been stripped out of this one. I would think those would help vent.
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SCUSEMWAU , I understood that ur new tank had no vents .
 
If you have dirt dobbers there and left line exposed they will stop it up over night. If you left one end unhooked run a piece of wire in it to see if it is blocked within 6 inches from end
 
famous bob said:
SCUSEMWAU , I understood that ur new tank had no vents .
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This tank had the 4 nipples to use with the evap/evac system, 71 apparently was the first year to do this. It's no longer in the car, presumably when they removed the slanty that was in there they removed all of that as well (they also removed and/or forgot the kickdown linkage which I didn't notice until later on). There were 4 hoses connected to the tank when I swapped the tank, and since I wasn't sure if it was a vented cap, I only hooked one of them back up, the one furthest to the rear bumper. This should be venting the tank pretty well I assume (the 3 empty nipples).
 
red67gts said:
If you have dirt dobbers there and left line exposed they will stop it up over night. If you left one end unhooked run a piece of wire in it to see if it is blocked within 6 inches from end
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Will be doing the work this weekend so that'll be one of the first things I check, thanks.
 
Mattax said:
Early ECS, aka Vapor Saver.
Heated Air Intake and "Vapor Saver" (Session 271) from the Master Technician's Service Conference
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Yep that was the system. The original owner of the car stripped out the slant 6 that was in the car for the 360 that's in there now and he removed all of that from the engine compartment just left the hoses connected to the original gas tank. Not sure what difference that was or is actually making but the car ran right up until I swapped the tank out and just connected the one hose.
 
BTW, how do you have the 4 vents connected? I would actually plug all 4 to prevent dirt and moisture from being sucked in under the car and avoid any fuel spillage or expansion overflow, and go out an buy a 'for-sure' vented gas cap. Some of them have valves only vent above a certain pressure level IIRC; I had one that had been on my '62 for years with the PO, that was made to vent only above a pressure level; one day it decided to stick and 'foooom!' the gas tank got sucked in after driving 2 miles! A trip to the NAPA store fixed that!
 
nm9stheham said:
BTW, how do you have the 4 vents connected? I would actually plug all 4 to prevent dirt and moisture from being sucked in under the car and avoid any fuel spillage or expansion overflow, and go out an buy a 'for-sure' vented gas cap. Some of them have valves only vent above a certain pressure level IIRC; I had one that had been on my '62 for years with the PO, that was made to vent only above a pressure level; one day it decided to stick and 'foooom!' the gas tank got sucked in after driving 2 miles! A trip to the NAPA store fixed that!
Click to expand...

I re-connected the one that was furthest to the rear thinking it was actually for a vent since it looks slightly different, the rest are uncapped. I can cap them all up this weekend and pick up a truly vented cap if I can find one.
 
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