New gas tank

[mustangramair]

It's been a very long time since I have posted. My fox, that I have had since 2000 had some rott on the passenger side shock tower. The old 302 was also leaking from the rear main. I pulled the motor and had the shock tower fixed. Since the motor was out, I decided to put in a 331 stroker. The car has been out of commission for 18 months.

A huge thanks to the guys who set up the surging idle check list and the cranks but does not start check list! A long story short, the main ground was stuffed down in the fender apron, so it did not even crank. I found that, and screwed it into the block and the car would turn over. Then the fuel pump would run continuously. Turned out to be bad capacitors in the ECM. The car was not getting spark. Turned out to be the TFI Module. The car would start but not idle. The IAC was bad. I could get it to idle, but it liked to die! I reset the base idle, and it idles like a champ! I finally took the car out, and it stalled coming to a stop. The VSS was bad. I replaced that, and now the car drives great!

Which leads me to this. During this process I put a new gas tank in. It had an 1/8 of a tank while I was working on all the issues. I took it to the gas station yesterday and filled it up. It leaked very badly from the middle of the tank. The fuel was coming through the middle vents on the plastic case holding the tank. The filler neck gasket is also brand new and was bone dry. I scoped the top of the tank. I couldn't see much. The return lines...I believe were also dry. It leaked until it was at 3/4 of a tank. Does anyone have an idea what is causing the leak? Could it just be a bad tank? I'll also be calling LMR about this.

Thanks!
Nick

 

[Mustang5L5]

Honestly, no way to tell. Really need to drop the tank and see. Given that it leaked when full, my guess is it's the fuel filler grommet. Can you investigate that as it's in the open on the side.

The non Ford filler grommets are notorious for tearing even when new, especially Dorman. If you didn't use a Ford one, get the OEM Ford one if yours is in fact leaking

 

[mustangramair]

Thanks for the advice! When I say leaking, I mean pouring! I still have half a tank to burn through before I drop the tank. The amount that poured out was shocking. The fuel neck grommet was dry and it was pouring from a different spot. I’ll definitely take a look at it when I drop the tank.

 

[Mustang5L5]

That's very interesting. Perhaps seam in tank split when the straps tighten up on it?

Unsure what manufacturer LRS is using these days. If it is faulty, I'd go with a Spectra Premium from rockauto. Slightly cheaper too

 

[General karthief]

You can get a discount from rockauto too
https://www.stangnet.com/mustang-fo...or-parts-more-expires-october-13-2018.904672/

 

[95BlueStallion]

Both @Mustang5L5 and I put Spectra tanks in our cars. So far so good for me. If you replace it again, I'd suggest that brand. It pretty much has to be the seam if you are confident its not the filler grommet or one of the fuel line connections.

 

[mustangramair]

Thanks guys! I was wondering about the seam myself. Could it also be the rubber gaskets under the metal rings that hold the fuel level sensor? That was the area I think it may have been coming from.

Install on the new tank was very easy! I didn’t have to wrestle it in. Hopefully I was not the cause of the leaking.

 

[Mustang5L5]

It could be, but being on the very top they would need to have slipped badly or not be installed.

Basically you have three possibilities. Let us know what you find

 

[91TwighlightGT]

My spectra tank has also bee problem free.