S14 , weird fuel leak, anyone seen this? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

omgosh · 07-30-2014, 02:20 PM

So my S14 is leaking gas, seemingly out of the fuel pump plugs. There is no gas anywhere on the sides or the bottom of the tank. When I shut the car off, especially when it is hot, the two fuel pump plugs begin to fill up with gas. This is causing the weather seal inside the plugs to swell up and results in the plugs becoming disconnected.

I am assuming its leaking from the bulkhead-type electrical connector but I cant tell while the sender is still installed...

However, I was thinking maybe it was related to the fact that I do not have the EVAP system hooked up. I just put an SR20DE in the car and do not have the requisite solenoid and charcoal cannister so I just plugged the engine side line and left the gas tank side vented. Maybe the lack of suction in the tank is causing the gas to push through the bulkhead connectors?

Thanks for any input

itsjustdaphne · 08-01-2014, 01:38 AM

There's three hoses on the fuel sender. Feed. Return. Vent. (Vent is smallest I believe). Make sure the vent is not clogged and or plugged up in the engine bay .

Kingtal0n · 11-27-2017, 12:20 PM

I have this exact same problem, fuel is creeping out of the plug-area when the tank builds pressure. I let the cap loose and it stops.

On the S14 tank, that 3rd line isnt a vent, its some kind of fuel transfer tube. Fuel returning from the tank is used to pull a vacuum on that line, drawing fuel from one side of the tank to the other. It keeps all the fuel on the side where the pump is.

So, here is where I am stuck. Either the "bulkhead" is cracked and I just need to replace it. Or, the bulkhead has some kind of safety-check valve that leaking in that spot to let me know the "vent" line is clogged, which apparently is a line that runs to a "Fuel valve" under the trunk area, and from there to the front of the car. It is possible this device has filled with fuel and since the Original engine is gone, it no longer operates, and now I have no more vent.

Q: Do I need to put a switch on the fuel valve and power it up, to send fuel to the front of the car, and install a charcoal canister there now? Or do I just need to change the cracked bulkhead? I plan to change the whole tank and all lines and everything at once, and I would like to take care of any EGR style mods also. I wonder if I could trap it in a charcoal canister, in the rear of the car (instead of engine bay, I dont see why not) and then redirect it back into the tank somehow when activated (instead of into the engine). There must be a reason the factory doesn't do this so I am guessing its not going to work.

gaz_moose · 11-28-2017, 11:20 AM

check the valve in your fuel cap works by sucking and blowing on it.
ive seen the caps stop working before.

over here on our SR equipped cars as standard I always just rip all the carbon canister stuff out and leave the hard line that runs under the car so that it vents out by where the front footwell meets the bulkhead.

cclark · 08-26-2018, 05:52 AM

Quote:

Originally Posted by Kingtal0n

I have this exact same problem, fuel is creeping out of the plug-area when the tank builds pressure. I let the cap loose and it stops.

On the S14 tank, that 3rd line isnt a vent, its some kind of fuel transfer tube. Fuel returning from the tank is used to pull a vacuum on that line, drawing fuel from one side of the tank to the other. It keeps all the fuel on the side where the pump is.

So, here is where I am stuck. Either the "bulkhead" is cracked and I just need to replace it. Or, the bulkhead has some kind of safety-check valve that leaking in that spot to let me know the "vent" line is clogged, which apparently is a line that runs to a "Fuel valve" under the trunk area, and from there to the front of the car. It is possible this device has filled with fuel and since the Original engine is gone, it no longer operates, and now I have no more vent.

Q: Do I need to put a switch on the fuel valve and power it up, to send fuel to the front of the car, and install a charcoal canister there now? Or do I just need to change the cracked bulkhead? I plan to change the whole tank and all lines and everything at once, and I would like to take care of any EGR style mods also. I wonder if I could trap it in a charcoal canister, in the rear of the car (instead of engine bay, I dont see why not) and then redirect it back into the tank somehow when activated (instead of into the engine). There must be a reason the factory doesn't do this so I am guessing its not going to work.

Did you ever figure this out? This is happening to me now. I’m Buying a new gas cap and gas tank bulkhead but I’m with you, not sure that’s the main problem.

Sent from my iPhone using Tapatalk

Kingtal0n · 08-26-2018, 10:33 AM

Oh yes

I swapped the top part (big round yellow/white plastic thing, "bulk head"). I guess the old one just had a crack somewhere.

This one is from an S15 I think. it has the fuel lines on opposite sides. I needed that anyways because I relocated my hard fuel lines to the other side of the car.
Then braided hose with hose clamps is track legal and safer for my application than AN fittings.

cclark · 08-27-2018, 07:46 AM

Quote:

Originally Posted by Kingtal0n

Oh yes

I swapped the top part (big round yellow/white plastic thing, "bulk head"). I guess the old one just had a crack somewhere.

Okay, perfect! Just ordered a new one....let's see if this does it

TheVinylKingz · 06-14-2020, 03:09 PM

Quote:

Originally Posted by cclark

Okay, perfect! Just ordered a new one....let's see if this does it

I had to replace mine ?bulkhead? these are discontinued, but there are a few that have the earlier 3 wire connection vs 4, basically if you have a 96-98 s14 you?re screwed bc one of the plugs is a 4 pin connection plug, 95 s14 were all 3 plug. You the other connection is the same on all years.

I bought one on eBay and it worked out well!

S14rebuild · 06-15-2020, 04:35 AM

Quote:

Originally Posted by TheVinylKingz

I had to replace mine ?bulkhead? these are discontinued, but there are a few that have the earlier 3 wire connection vs 4, basically if you have a 96-98 s14 you?re screwed bc one of the plugs is a 4 pin connection plug, 95 s14 were all 3 plug. You the other connection is the same on all years.

I bought one on eBay and it worked out well!

Bruhh 2 year old post....

07-30-2014, 02:20 PM	#1
omgosh Zilvia Member Join Date: Mar 2005 Location: Tampa FL Posts: 210 Trader Rating: (0) Feedback Score: 0 reviews	S14 , weird fuel leak, anyone seen this? So my S14 is leaking gas, seemingly out of the fuel pump plugs. There is no gas anywhere on the sides or the bottom of the tank. When I shut the car off, especially when it is hot, the two fuel pump plugs begin to fill up with gas. This is causing the weather seal inside the plugs to swell up and results in the plugs becoming disconnected. I am assuming its leaking from the bulkhead-type electrical connector but I cant tell while the sender is still installed... However, I was thinking maybe it was related to the fact that I do not have the EVAP system hooked up. I just put an SR20DE in the car and do not have the requisite solenoid and charcoal cannister so I just plugged the engine side line and left the gas tank side vented. Maybe the lack of suction in the tank is causing the gas to push through the bulkhead connectors? Thanks for any input __________________

08-26-2018, 10:33 AM	#6
Kingtal0n Post Whore! Join Date: Jul 2005 Location: South Florida Age: 38 Posts: 4,649 Trader Rating: (17) Feedback Score: 17 reviews	Oh yes I swapped the top part (big round yellow/white plastic thing, "bulk head"). I guess the old one just had a crack somewhere. This one is from an S15 I think. it has the fuel lines on opposite sides. I needed that anyways because I relocated my hard fuel lines to the other side of the car. Then braided hose with hose clamps is track legal and safer for my application than AN fittings. __________________ 5.3/4l80e/turbo 240sx playthrough: https://tinyurl.com/turbo240

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08-01-2014, 01:38 AM	#2
itsjustdaphne Zilvia Addict Join Date: Sep 2011 Location: South FL Posts: 785 Trader Rating: (12) Feedback Score: 12 reviews	There's three hoses on the fuel sender. Feed. Return. Vent. (Vent is smallest I believe). Make sure the vent is not clogged and or plugged up in the engine bay .

11-27-2017, 12:20 PM	#3
Kingtal0n Post Whore! Join Date: Jul 2005 Location: South Florida Age: 38 Posts: 4,649 Trader Rating: (17) Feedback Score: 17 reviews	I have this exact same problem, fuel is creeping out of the plug-area when the tank builds pressure. I let the cap loose and it stops. On the S14 tank, that 3rd line isnt a vent, its some kind of fuel transfer tube. Fuel returning from the tank is used to pull a vacuum on that line, drawing fuel from one side of the tank to the other. It keeps all the fuel on the side where the pump is. So, here is where I am stuck. Either the "bulkhead" is cracked and I just need to replace it. Or, the bulkhead has some kind of safety-check valve that leaking in that spot to let me know the "vent" line is clogged, which apparently is a line that runs to a "Fuel valve" under the trunk area, and from there to the front of the car. It is possible this device has filled with fuel and since the Original engine is gone, it no longer operates, and now I have no more vent. Q: Do I need to put a switch on the fuel valve and power it up, to send fuel to the front of the car, and install a charcoal canister there now? Or do I just need to change the cracked bulkhead? I plan to change the whole tank and all lines and everything at once, and I would like to take care of any EGR style mods also. I wonder if I could trap it in a charcoal canister, in the rear of the car (instead of engine bay, I dont see why not) and then redirect it back into the tank somehow when activated (instead of into the engine). There must be a reason the factory doesn't do this so I am guessing its not going to work.

11-28-2017, 11:20 AM	#4
gaz_moose Zilvia Member Join Date: Mar 2008 Location: engerland Posts: 242 Trader Rating: (0) Feedback Score: 0 reviews	check the valve in your fuel cap works by sucking and blowing on it. ive seen the caps stop working before. over here on our SR equipped cars as standard I always just rip all the carbon canister stuff out and leave the hard line that runs under the car so that it vents out by where the front footwell meets the bulkhead.