Draining the fuel tank

blipmode188

Member
Joined
Jun 28, 2007
I am a absolute newby to these cars so please bare with me.

I need to drain the gas tank to drop it to fix what i think is an electrical problem with the wires going to the pump and sending unit.
On a previous post someone mentioned that if you could find an R12 hose
that it would connect to the fuel rail fitting ?
Is that correct ?

I guess you would then have to find another fitting for the other end
and connect a hose to it also.
I know how to force the pump to run but is there anything else that i am missing ?

I think I can find that R12 hose but I guess I need some advice.

Anyone done this sort of thing before ?


Thanks

Steve
 
Lots of us do it all the time when it's time to put in race gas.

The R-12 hose has a Schrader valve coupler that spins directly onto the fuel rail (and depresses the valve). The "other" end (which normally connects to the can) is whatever suits your needs, so just cut-off the connector. It could simply be an open hose that you put into the spout of your gas can.

Advice: When the tank starts to get empty, the gas stream will start to pulsate. Unplug the fuel pump immediately, to prevent pump damage.
 
Could somebody post more detailed instructions on how to do this???

I am going to be buying an 86 GN that hasn't run in a few years, so I think draining the tank is a good idea before my 800 mile trip home.:wink:

Do you pressurize the fuel return line and then blow old fuel out of the fuel line??? Also, is there a way to hot wire the fuel pump through the fuel pump relay and just let th pump drain the tank???

Sorry to hijack your thread. I guess if i get an answer it will help both of us lol.:smile:

TY in advance
John
 
if it hasnt run for a few years i would drop the tank to get the fuel out . then i would put some fresh gas in it after i changed the fuel filter and then drain fuel out of the fuel rail.
 
Could somebody post more detailed instructions on how to do this???

Also, is there a way to hot wire the fuel pump through the fuel pump relay and just let th pump drain the tank???

Sorry to hijack your thread. I guess if i get an answer it will help both of us lol.:smile:

TY in advance
John

I agree with Boost231.
Even so, when it comes time to need to run the fuel pump, all you need to do is to look for a gray wire with a black female spade connector in the loom behind the alternator. If you apply 12 volts, this will turn on the pump. I often just unplug the hood light, and plug it into the gray fuel pump prime wire.
 
any different way of draining the tank on a TTA or is it the same method---any pics of underhood so I can see where the wires are ????
 
I do this all the time to get the 94 out to put race fuel in at the track. All you need is a 6ft piece of hose, jumper wire and a fuel can. I will take a picture tomorrow of the set up and wire location. It is just too damn cold in the garage to do it now:eek: btw - a TTA should be the same.
 
any different way of draining the tank on a TTA or is it the same method---any pics of underhood so I can see where the wires are ????

Here's is what the connector looks like to activate the pump.
 

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and you connect that connector to the positive behind the alternator?

You connect that connector to a power source to activate the pump. I just run a 3-4 foot wire directly from the battery. If you have an underhood light, you can use that.
 
You connect that connector to a power source to activate the pump. I just run a 3-4 foot wire directly from the battery. If you have an underhood light, you can use that.

The connector for the underhood light is a perfect mate to plug into the fuel pump test connector (black) behind the alternator. The hood light wire is "hot" at all times. An older type R-12 A/C hose is preferable. I just use clear plastic 3/8" hose.
HTH
 
The plug is on the drivers side by the alternator or AC unit. It appears to be disconnected or go nowhere
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Make a little jumper wire with a male spade on one side and aligator clip on the other.
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Open up the schrader valve on the fuel rail and run a 3/8 hose to a gas can. Plug the spade into the fuel pump plug, attach the aligator clip to the red (hot) post of the alternator.
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It will pump the gas right out of the tank for you. When the fuel starts pulsating or your see gaps in the flow, then disconnect the wire as it is almost completely empty and you don't want to suck up dirt or burn up the pump. A TTA should be identical. Hope that helps.
 
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