Replaced gas tank, won't start!

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KJoeZ61

KJoeZ61

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i just replace my gas tank and sending unit. Won't start! I put four gallons in turned it over and it ran for a half minute. I pulled the sending unit and the tube isn't blocked, but there didn't appear to be gas in the hose when I disconnected it. Shouldn't my fuel pump pick it up?
 
Maybe someone left something in there??

I'd pull the supply tube "loose" at both ends (goes from rear to front of car) and blow it out make sure it's clear

Inspect your connecting hoses make sure they are not collapsing.

Then take some hose and a container. You should be able to start a siphon from the tank fitting and get fuel to "gravity drain."
 
The hoses and lines are new, I replaced them last fall. I replace everything but the fuel tank then and noticed the vent tube coming out of the tank was just dangling there, that's why I replaced the tank.
 
Aftermarket sending unit I assume?
If so, while the tank was out, did you look through the filler neck hole and see if it was reaching all the way to the bottom of the tank?
 
Even if the pickup tube location isn't the problem, are you aware of the drawbacks of aftermarket sending units vs original?
 
KJoeZ61 said:
Just pulled the old sending unit. Tomorrow I'll compare them. Hopefully it's going to be that easy!
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I like to blow in the line at the fuel pump and listen for bubbles.
Hey, it answers the question. :D
 
KJoeZ61 said:
i just replace my gas tank and sending unit. Won't start! I put four gallons in turned it over and it ran for a half minute. I pulled the sending unit and the tube isn't blocked, but there didn't appear to be gas in the hose when I disconnected it. Shouldn't my fuel pump pick it up?
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Probably not enough time in half a minute at or near idle, to suck it to the front.
But that doesn't explain the empty line.
Furthermore, there should be more than a half a minutes fuel in the bowls of most carbs.I'm thinking more like two or even three at idle.
Blowing air back from the front is a great way to clear the line and prove it's not plugged. However, it does nothing to prove the pump can suck fuel up. If there is any place the pump can suck air, it will.
 
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If you put some fuel in carb barrels will it fire?
You can disconnect the inlet to the fuel pump, hook up a hose and feed it from a fuel can (safely). If it fires and runs it is issue from line back to tank. If not pump to carb
 
Get the fuel pump primed up, put some suction on the line from the fuel pump to the carb when you see that pump pushing the fuel out reconnect the line to the carb also check the filter in the carb if equipped.
 
It's not the carb, I'm sure of that. And actually it probably ran a minute or two before it quit. Everything was fine until I replaced the tank today. After it stopped running when I pulled the fuel line off the sending unit there was no gas in the hose. I'm pretty certain it's between the sending unit and the fuel pump.

The fuel pump wasn't an issue before, it was also replaced last fall. It's an Auto Zone special. I'll put the old sending unit back in it tomorrow, at least I know that one worked. Even the fuel gauge worked.
 
Capt46 said:
If your fuel pump is air bound you have to get it primed
Click to expand...

Sorry, no. Fuel pumps should self prime. If they don't there is something wrong......plugged, bad valves, bad pump, whatever
 
KJoeZ61 said:
It's not the carb, I'm sure of that. And actually it probably ran a minute or two before it quit. Everything was fine until I replaced the tank today. After it stopped running when I pulled the fuel line off the sending unit there was no gas in the hose. I'm pretty certain it's between the sending unit and the fuel pump.

The fuel pump wasn't an issue before, it was also replaced last fall. It's an Auto Zone special. I'll put the old sending unit back in it tomorrow, at least I know that one worked. Even the fuel gauge worked.
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Did you do what I told you? DO NOT ASSUME.......... There might have been some garbage in the sender, plugged the line. Don't you have a vacuum gauge? BUY one they are cheap. READ the shop manual. Any pump should pull at least 10-12" or more vacuum "when cranking."

You cannot stand there and look at it and guess. Well, you can...........
 
I'm actually ashamed to admit this, but I will. You know the little shipping plugs they put on the ends of tubes. Need I say anymore? But I did learn one other thing, the old sending units pipe sits about 2-2/2" lower than the replacement. Since the sender on the original one worked its the one back on the car.
Anyway the plug sucked up the rubber connecting hose so it couldn't be seen. Pulled off the connecting hose and shook my head!

thanks everyone and have a good laugh.....
 
Saw a guy install his battery and left the safety caps on the posts.

I paid a local shop to repair my a/c leak and retrofit it to r134.
Left the caps on the reciever dryer and destroyed my whole a/c system. Chunks of plastic everywhere.

A simple mistake,at least you found it.

A good prank is a ball bearing in the line,or in a vacuum hose.
 
I'm not sure what car and tank you have, but I bought a replacement tank and sending unit for my 67 Barracuda. I also did some testing. The first 3.5 gallons do NOT count!

Right around 3.5 gallons, the float starts to move and the suction tube starts to get submerged. So with 4 gallons, you are right on the threshold. Try putting in at least two more gallons, and try it again.

Whoops. I just read that you did find the problem. My answer still applies.
 
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I bent my pick-up tube down so the sock is on the bottom. THen I did the same to the float. Now I know that when my gauge reads empty, I better be really close to a filling station.
But when the tank is full,it takes a really long time before the gauge starts moving, I get really great fuel mileage on the top half,lol.
 
KJoeZ61 said:
I'm actually ashamed to admit this, but I will. You know the little shipping plugs they put on the ends of tubes. Need I say anymore? But I did learn one other thing, the old sending units pipe sits about 2-2/2" lower than the replacement. Since the sender on the original one worked its the one back on the car.
Anyway the plug sucked up the rubber connecting hose so it couldn't be seen. Pulled off the connecting hose and shook my head!

thanks everyone and have a good laugh.....
Click to expand...
That's a common story with aftermarket sending units. Good decision to put the original back in -- unless you have a need for an aftermarket sending unit such as larger fuel lines or fuel return built into the sending unit, its best to stick with OEM. Several places can rebuild them if needed also.

Glad you found it.
 
Jeez...I was thinking just that but thought...naaaa...couldn't be...lol.
 
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