Gas Tank Issues

[Nathanhasacarr]

Hello all,

I have a 1991 s13 and I am having issues with my gas tank.

First my fuel gauge is not working. (My guess is the sending unit, from further research)

My tank is not holding pressure.

My car smells like gas and it is not coming from the injectors it is coming from the tank. When I take a hard turn the smell is worse and when right after I fill up it smells strong. It is not as bad when I do not have as much gas left. On the underside of the tank I see what looks to be dried gasoline (see picture). Sometimes the car bogs down as well. I lifted up the cover in the trunk to see the top of the tank everything looked very old (see picture).

I believe I have a leak towards the top of the tank. Is there a gasket I should be looking for or a potentially cracked or broken hose that could be causing this? Should I drop the tank to fix all of these issues including the fuel sending unit? Should I replace other things while im at it ( i.e. hoses, gaskets, evap. canister and other things that are prone to fail while fixing this)? Much thanks for the help!

Notice in the picture of the wires above the tank it looks like the previous owner messed with the one going to the taillight not sure if they look right.

[dallasb53]

Hello all,

I have a 1991 s13 and I am having issues with my gas tank.

First my fuel gauge is not working. (My guess is the sending unit, from further research)

My tank is not holding pressure.

My car smells like gas and it is not coming from the injectors it is coming from the tank. When I take a hard turn the smell is worse and when right after I fill up it smells strong. It is not as bad when I do not have as much gas left. On the underside of the tank I see what looks to be dried gasoline (see picture). Sometimes the car bogs down as well. I lifted up the cover in the trunk to see the top of the tank everything looked very old (see picture).

I believe I have a leak towards the top of the tank. Is there a gasket I should be looking for or a potentially cracked or broken hose that could be causing this? Should I drop the tank to fix all of these issues including the fuel sending unit? Should I replace other things while im at it ( i.e. hoses, gaskets, evap. canister and other things that are prone to fail while fixing this)? Much thanks for the help!

Notice in the picture of the wires above the tank it looks like the previous owner messed with the one going to the taillight not sure if they look right.

open your bible(FSM) and all your questions shall be answered.

[e1_griego]

You need to replace the o-ring on the fuel pump assembly, most likely.

[Nathanhasacarr]

Cool thanks for the response and this could be as related issue, my car fluctuates from running decent to running rich. AFR usually at 13ish when idling but is now at 10ish and when I accelerate it bogs down at 9.5 not in boost.

[zerodameaon]

The O ring can be had at Enjuku for about 15 bucks, and your rich issues could be something related to your wiring. If I am looking at that right, is your fuel pump wired to your tail lights?

[Mikester]

... Or you can say "Fuck Enjuku's inflated prices" and get the o-ring from Nissan or any number of other places for $5.00 & change lol

OP, Dropping the tank and fully fixing EVERYTHING is cheap and a lot easier than it may seem. Your tank should never be under pressure, only vacuum... Under pressure is a recipe for things going BOOM lol. The FP carrier looks like shit- and the lines look like they needed to be replaced about a decade ago. 5/16" fuel line is about $1 per foot at your local Vatozone; and as stated above, that o-ring is about $5.

I wonder if the leak is at the filler neck based on the underside of the tank... Off the filler, there is a secondary hose- and also a gasket where the neck bolts to the tank. Seriously recommend you drop it and address everything properly... Not just because of the fuel smell; but because of your safety and gas mileage ;)

Good luck~

Mike

[zerodameaon]

Inflated? Got links to the cheaper spots? All the local dealers want upwards of $20.

[e1_griego]

Last time i bought one it was $11 from the local dealer.

[di-devol]

Ace hardware, boat o-rings. $2.50

[Nathanhasacarr]

Good call mikester dropped the tank it looks like the filler neck gasket is shot and the gasket for the fuel pump is gonarehha as well. I will hook up sending unit to a multimeter tonight. And while I'm at it I'll replace those hoses. Is it 1/4 or 5/16 fuel line? I think I'll just use rtv to replace the seals. Thanks for help everyone!

[Nathanhasacarr]

And I have no idea what the hell is going on with the wiring it could also be the culprit for an inop gauge. And no the fluctuating AFR is not because of my idle it does through all driving. Idles relatively smooth at 8-1000.

I think zerodameaon might be right with wiring issue...

Does anyone have a wiring diagram for the fuel sending system? Or atleast what color it is? Could the wire going to the tail light be the reason that my gauge is not receiving a signal?

[Nathanhasacarr]

Replaced all the hoses and gaskets smell is gone! I have the sending unit out and it looks like one of the wires is not attached. I pulled off a wire that looks to be yellow w/green stripe. Is there another wire that should be attached? Multimeter is broken so will test it tomorrow! Does anyone have an idea on how to just get the fuel sending unit, other than a junkyard? Parts store want me to buy the whole assembly to replace just the sending unit.

[Nathanhasacarr]

Sending unit tested good but it looks like a wire is missing. The only wire I have running to it is a yellow one. There looks to be a spot where a wire was soldered and fell off. Anyone know if this is right? https://us-mg6.mail.yahoo.com/neo/launch?.rand=f09tvhpjep6h2#

http://us-mg6.mail.yahoo.com/ya/download?mid=2_0_0_1_1968423_AFr0i2IAABZAUtSDWwAAA CHebls&pid=4&fid=Inbox&inline=1

[Mikester]

Inflated? Got links to the cheaper spots? All the local dealers want upwards of $20.

www.ebay.com (http://www.ebay.com)
www.frsport.com (http://www.frsport.com)
www.jcwhitney.com (http://www.jcwhitney.com)
www.thenismoshop.com (http://www.thenismoshop.com)
www.amazon.com (http://www.amazon.com)

to name a few.

You can also try West Covina Nissan's online store- they always have amazing deals on OEM replacement parts...

First time I went to Enjuku and saw them charging $15 for a pilot bushing that was $2.50 at several other stores... and the incredible wealth of ISIS and other substandard bullshit parts they push, I decided that no matter how cool Ken is (I do hear from several folks he is a really is a nice dude that takes good care of his customers), I personally will never shop there unless they happen to be the only place that has something I need. To date, that hasn't happened. My opinion only.

/end rant