Mike there are three potential spots on the 91 4.0L to check:
1. The fuel filter input and output lines.
2. The fuel tank sending unit gasket -- This was a recall item some years
ago.
3. The fuel fill lines.

1 is easy to check. Just crawl under the left rear and look up at where the
fuel filter is, tucked up against the frame behind the left rear wheel.
Look for any wet spots or evidence of dripping on the inside of the rear
tire.

2 Can be checked by looking between the fuel tank and fuel tank skid plate
just aft of the left rear wheel. If it looks wet just after a fill-up, then
suspect the sending unit gasket located on the top of the tank. To repair
this the gas tank skidplate and tank must be dropped and removed from the
vehicle.

3 is checked by pulling down the mudflap at the bottom rear left corner
below the taillight. Use a flashlight to look up toward the fuel filler
lines to check for wetness and drips.

Scott
"jeff" <jalowe44INVALID@hotmail.com.INVALID> wrote in message
news:hokkg.7207$WM4.781@trnddc01...
> If you live anywhere near the rust belt another possibility is the tubes
> on the top of the fuel sender. My '91 recently developed a hairline crack
> in the return line. Since the gas gage hasn't worked for years I went
> ahead and bought a Crown sender/pump for around $185.
>
>
> ryan.a.jamieson@gmail.com wrote:
>> Hey all, I have a '91 Wrangler I-6 4.0 and I've been smelling fuel
>> vapors as of late. After I'm driving I inspect the undercarriage to
>> see if I can find the source, but I'm unable to. The odor is strongest
>> in the rear driver's side wheel well, and there seems to be a liquid
>> leak in that vicinity, as the grime I wipe off my axle and
>> undercarriage smells of gasoline. I've taken it to my local mechanic
>> (not a jeep dealer) and he was unable to find the source of any leak.
>> I know my nose is not lying. Anyone have any ideas?
>>

 

Mike there are three potential spots on the 91 4.0L to check:
1. The fuel filter input and output lines.
2. The fuel tank sending unit gasket -- This was a recall item some years
ago.
3. The fuel fill lines.

1 is easy to check. Just crawl under the left rear and look up at where the
fuel filter is, tucked up against the frame behind the left rear wheel.
Look for any wet spots or evidence of dripping on the inside of the rear
tire.

2 Can be checked by looking between the fuel tank and fuel tank skid plate
just aft of the left rear wheel. If it looks wet just after a fill-up, then
suspect the sending unit gasket located on the top of the tank. To repair
this the gas tank skidplate and tank must be dropped and removed from the
vehicle.

3 is checked by pulling down the mudflap at the bottom rear left corner
below the taillight. Use a flashlight to look up toward the fuel filler
lines to check for wetness and drips.

Scott
"jeff" <jalowe44INVALID@hotmail.com.INVALID> wrote in message
news:hokkg.7207$WM4.781@trnddc01...
> If you live anywhere near the rust belt another possibility is the tubes
> on the top of the fuel sender. My '91 recently developed a hairline crack
> in the return line. Since the gas gage hasn't worked for years I went
> ahead and bought a Crown sender/pump for around $185.
>
>
> ryan.a.jamieson@gmail.com wrote:
>> Hey all, I have a '91 Wrangler I-6 4.0 and I've been smelling fuel
>> vapors as of late. After I'm driving I inspect the undercarriage to
>> see if I can find the source, but I'm unable to. The odor is strongest
>> in the rear driver's side wheel well, and there seems to be a liquid
>> leak in that vicinity, as the grime I wipe off my axle and
>> undercarriage smells of gasoline. I've taken it to my local mechanic
>> (not a jeep dealer) and he was unable to find the source of any leak.
>> I know my nose is not lying. Anyone have any ideas?
>>

 

Mike there are three potential spots on the 91 4.0L to check:
1. The fuel filter input and output lines.
2. The fuel tank sending unit gasket -- This was a recall item some years
ago.
3. The fuel fill lines.

1 is easy to check. Just crawl under the left rear and look up at where the
fuel filter is, tucked up against the frame behind the left rear wheel.
Look for any wet spots or evidence of dripping on the inside of the rear
tire.

2 Can be checked by looking between the fuel tank and fuel tank skid plate
just aft of the left rear wheel. If it looks wet just after a fill-up, then
suspect the sending unit gasket located on the top of the tank. To repair
this the gas tank skidplate and tank must be dropped and removed from the
vehicle.

3 is checked by pulling down the mudflap at the bottom rear left corner
below the taillight. Use a flashlight to look up toward the fuel filler
lines to check for wetness and drips.

Scott
"jeff" <jalowe44INVALID@hotmail.com.INVALID> wrote in message
news:hokkg.7207$WM4.781@trnddc01...
> If you live anywhere near the rust belt another possibility is the tubes
> on the top of the fuel sender. My '91 recently developed a hairline crack
> in the return line. Since the gas gage hasn't worked for years I went
> ahead and bought a Crown sender/pump for around $185.
>
>
> ryan.a.jamieson@gmail.com wrote:
>> Hey all, I have a '91 Wrangler I-6 4.0 and I've been smelling fuel
>> vapors as of late. After I'm driving I inspect the undercarriage to
>> see if I can find the source, but I'm unable to. The odor is strongest
>> in the rear driver's side wheel well, and there seems to be a liquid
>> leak in that vicinity, as the grime I wipe off my axle and
>> undercarriage smells of gasoline. I've taken it to my local mechanic
>> (not a jeep dealer) and he was unable to find the source of any leak.
>> I know my nose is not lying. Anyone have any ideas?
>>

 

Cool. After reading all these I got under there again and did some
snooping. The fuel filter looked and smelled fine, no strong odors
there. I moved that flap and nosed around with a flashlight and it
seems to be coming from above my fuel tank, which would indicate a
busted gasket. So now I get to go on the adventure of fixing it. Any
suggestions?


reconair wrote:
> Mike there are three potential spots on the 91 4.0L to check:
> 1. The fuel filter input and output lines.
> 2. The fuel tank sending unit gasket -- This was a recall item some years
> ago.
> 3. The fuel fill lines.
>
> 1 is easy to check. Just crawl under the left rear and look up at where the
> fuel filter is, tucked up against the frame behind the left rear wheel.
> Look for any wet spots or evidence of dripping on the inside of the rear
> tire.
>
> 2 Can be checked by looking between the fuel tank and fuel tank skid plate
> just aft of the left rear wheel. If it looks wet just after a fill-up, then
> suspect the sending unit gasket located on the top of the tank. To repair
> this the gas tank skidplate and tank must be dropped and removed from the
> vehicle.
>
> 3 is checked by pulling down the mudflap at the bottom rear left corner
> below the taillight. Use a flashlight to look up toward the fuel filler
> lines to check for wetness and drips.
>
> Scott
> "jeff" <jalowe44INVALID@hotmail.com.INVALID> wrote in message
> news:hokkg.7207$WM4.781@trnddc01...
> > If you live anywhere near the rust belt another possibility is the tubes
> > on the top of the fuel sender. My '91 recently developed a hairline crack
> > in the return line. Since the gas gage hasn't worked for years I went
> > ahead and bought a Crown sender/pump for around $185.
> >
> >
> > ryan.a.jamieson@gmail.com wrote:
> >> Hey all, I have a '91 Wrangler I-6 4.0 and I've been smelling fuel
> >> vapors as of late. After I'm driving I inspect the undercarriage to
> >> see if I can find the source, but I'm unable to. The odor is strongest
> >> in the rear driver's side wheel well, and there seems to be a liquid
> >> leak in that vicinity, as the grime I wipe off my axle and
> >> undercarriage smells of gasoline. I've taken it to my local mechanic
> >> (not a jeep dealer) and he was unable to find the source of any leak.
> >> I know my nose is not lying. Anyone have any ideas?
> >>

 

Cool. After reading all these I got under there again and did some
snooping. The fuel filter looked and smelled fine, no strong odors
there. I moved that flap and nosed around with a flashlight and it
seems to be coming from above my fuel tank, which would indicate a
busted gasket. So now I get to go on the adventure of fixing it. Any
suggestions?


reconair wrote:
> Mike there are three potential spots on the 91 4.0L to check:
> 1. The fuel filter input and output lines.
> 2. The fuel tank sending unit gasket -- This was a recall item some years
> ago.
> 3. The fuel fill lines.
>
> 1 is easy to check. Just crawl under the left rear and look up at where the
> fuel filter is, tucked up against the frame behind the left rear wheel.
> Look for any wet spots or evidence of dripping on the inside of the rear
> tire.
>
> 2 Can be checked by looking between the fuel tank and fuel tank skid plate
> just aft of the left rear wheel. If it looks wet just after a fill-up, then
> suspect the sending unit gasket located on the top of the tank. To repair
> this the gas tank skidplate and tank must be dropped and removed from the
> vehicle.
>
> 3 is checked by pulling down the mudflap at the bottom rear left corner
> below the taillight. Use a flashlight to look up toward the fuel filler
> lines to check for wetness and drips.
>
> Scott
> "jeff" <jalowe44INVALID@hotmail.com.INVALID> wrote in message
> news:hokkg.7207$WM4.781@trnddc01...
> > If you live anywhere near the rust belt another possibility is the tubes
> > on the top of the fuel sender. My '91 recently developed a hairline crack
> > in the return line. Since the gas gage hasn't worked for years I went
> > ahead and bought a Crown sender/pump for around $185.
> >
> >
> > ryan.a.jamieson@gmail.com wrote:
> >> Hey all, I have a '91 Wrangler I-6 4.0 and I've been smelling fuel
> >> vapors as of late. After I'm driving I inspect the undercarriage to
> >> see if I can find the source, but I'm unable to. The odor is strongest
> >> in the rear driver's side wheel well, and there seems to be a liquid
> >> leak in that vicinity, as the grime I wipe off my axle and
> >> undercarriage smells of gasoline. I've taken it to my local mechanic
> >> (not a jeep dealer) and he was unable to find the source of any leak.
> >> I know my nose is not lying. Anyone have any ideas?
> >>

 

Cool. After reading all these I got under there again and did some
snooping. The fuel filter looked and smelled fine, no strong odors
there. I moved that flap and nosed around with a flashlight and it
seems to be coming from above my fuel tank, which would indicate a
busted gasket. So now I get to go on the adventure of fixing it. Any
suggestions?


reconair wrote:
> Mike there are three potential spots on the 91 4.0L to check:
> 1. The fuel filter input and output lines.
> 2. The fuel tank sending unit gasket -- This was a recall item some years
> ago.
> 3. The fuel fill lines.
>
> 1 is easy to check. Just crawl under the left rear and look up at where the
> fuel filter is, tucked up against the frame behind the left rear wheel.
> Look for any wet spots or evidence of dripping on the inside of the rear
> tire.
>
> 2 Can be checked by looking between the fuel tank and fuel tank skid plate
> just aft of the left rear wheel. If it looks wet just after a fill-up, then
> suspect the sending unit gasket located on the top of the tank. To repair
> this the gas tank skidplate and tank must be dropped and removed from the
> vehicle.
>
> 3 is checked by pulling down the mudflap at the bottom rear left corner
> below the taillight. Use a flashlight to look up toward the fuel filler
> lines to check for wetness and drips.
>
> Scott
> "jeff" <jalowe44INVALID@hotmail.com.INVALID> wrote in message
> news:hokkg.7207$WM4.781@trnddc01...
> > If you live anywhere near the rust belt another possibility is the tubes
> > on the top of the fuel sender. My '91 recently developed a hairline crack
> > in the return line. Since the gas gage hasn't worked for years I went
> > ahead and bought a Crown sender/pump for around $185.
> >
> >
> > ryan.a.jamieson@gmail.com wrote:
> >> Hey all, I have a '91 Wrangler I-6 4.0 and I've been smelling fuel
> >> vapors as of late. After I'm driving I inspect the undercarriage to
> >> see if I can find the source, but I'm unable to. The odor is strongest
> >> in the rear driver's side wheel well, and there seems to be a liquid
> >> leak in that vicinity, as the grime I wipe off my axle and
> >> undercarriage smells of gasoline. I've taken it to my local mechanic
> >> (not a jeep dealer) and he was unable to find the source of any leak.
> >> I know my nose is not lying. Anyone have any ideas?
> >>

 

ryan.a.jamieson@gmail.com did pass the time by typing:
> Cool. After reading all these I got under there again and did some
> snooping. The fuel filter looked and smelled fine, no strong odors
> there. I moved that flap and nosed around with a flashlight and it
> seems to be coming from above my fuel tank, which would indicate a
> busted gasket. So now I get to go on the adventure of fixing it. Any
> suggestions?

pbBlaster on the bolts and what ever you do, make sure you drain the tank. :)

Seriously, gas is very heavy and even a partially filled tank is no fun.
A floor jack and piece of plywood with some jack stands will help hold
things up while you lower it a bit to get at the connections. Fuel line (2),
wiring, fuel fill and vapor release lines, and the vapor line that runs
up to the canister.

The leak from above could be simply a cracked line or a rotted O ring
seal. It's also possible the vent line to the charcoal canister is
cracked.

You don't know till it's down.

--
DougW

 

ryan.a.jamieson@gmail.com did pass the time by typing:
> Cool. After reading all these I got under there again and did some
> snooping. The fuel filter looked and smelled fine, no strong odors
> there. I moved that flap and nosed around with a flashlight and it
> seems to be coming from above my fuel tank, which would indicate a
> busted gasket. So now I get to go on the adventure of fixing it. Any
> suggestions?

pbBlaster on the bolts and what ever you do, make sure you drain the tank. :)

Seriously, gas is very heavy and even a partially filled tank is no fun.
A floor jack and piece of plywood with some jack stands will help hold
things up while you lower it a bit to get at the connections. Fuel line (2),
wiring, fuel fill and vapor release lines, and the vapor line that runs
up to the canister.

The leak from above could be simply a cracked line or a rotted O ring
seal. It's also possible the vent line to the charcoal canister is
cracked.

You don't know till it's down.

--
DougW

 

ryan.a.jamieson@gmail.com did pass the time by typing:
> Cool. After reading all these I got under there again and did some
> snooping. The fuel filter looked and smelled fine, no strong odors
> there. I moved that flap and nosed around with a flashlight and it
> seems to be coming from above my fuel tank, which would indicate a
> busted gasket. So now I get to go on the adventure of fixing it. Any
> suggestions?

pbBlaster on the bolts and what ever you do, make sure you drain the tank. :)

Seriously, gas is very heavy and even a partially filled tank is no fun.
A floor jack and piece of plywood with some jack stands will help hold
things up while you lower it a bit to get at the connections. Fuel line (2),
wiring, fuel fill and vapor release lines, and the vapor line that runs
up to the canister.

The leak from above could be simply a cracked line or a rotted O ring
seal. It's also possible the vent line to the charcoal canister is
cracked.

You don't know till it's down.

--
DougW

 

In my '89 there is a rollover valve that is in
a small compartment behind the rear wheel,
passenger side. There is a black plastic cover
on the bottom. Remove this and look into the void.
You will see a few fuel lines connected to the valve.
I had to replace mine twice, they crack.
Joe
<ryan.a.jamieson@gmail.com> wrote in message
news:1150415300.838120.117620@p79g2000cwp.googlegr oups.com...
> Cool. After reading all these I got under there again and did some
> snooping. The fuel filter looked and smelled fine, no strong odors
> there. I moved that flap and nosed around with a flashlight and it
> seems to be coming from above my fuel tank, which would indicate a
> busted gasket. So now I get to go on the adventure of fixing it. Any
> suggestions?
>
>
> reconair wrote:
> > Mike there are three potential spots on the 91 4.0L to check:
> > 1. The fuel filter input and output lines.
> > 2. The fuel tank sending unit gasket -- This was a recall item some
years
> > ago.
> > 3. The fuel fill lines.
> >
> > 1 is easy to check. Just crawl under the left rear and look up at where
the
> > fuel filter is, tucked up against the frame behind the left rear wheel.
> > Look for any wet spots or evidence of dripping on the inside of the rear
> > tire.
> >
> > 2 Can be checked by looking between the fuel tank and fuel tank skid
plate
> > just aft of the left rear wheel. If it looks wet just after a fill-up,
then
> > suspect the sending unit gasket located on the top of the tank. To
repair
> > this the gas tank skidplate and tank must be dropped and removed from
the
> > vehicle.
> >
> > 3 is checked by pulling down the mudflap at the bottom rear left corner
> > below the taillight. Use a flashlight to look up toward the fuel filler
> > lines to check for wetness and drips.
> >
> > Scott
> > "jeff" <jalowe44INVALID@hotmail.com.INVALID> wrote in message
> > news:hokkg.7207$WM4.781@trnddc01...
> > > If you live anywhere near the rust belt another possibility is the
tubes
> > > on the top of the fuel sender. My '91 recently developed a hairline
crack
> > > in the return line. Since the gas gage hasn't worked for years I went
> > > ahead and bought a Crown sender/pump for around $185.
> > >
> > >
> > > ryan.a.jamieson@gmail.com wrote:
> > >> Hey all, I have a '91 Wrangler I-6 4.0 and I've been smelling fuel
> > >> vapors as of late. After I'm driving I inspect the undercarriage to
> > >> see if I can find the source, but I'm unable to. The odor is
strongest
> > >> in the rear driver's side wheel well, and there seems to be a liquid
> > >> leak in that vicinity, as the grime I wipe off my axle and
> > >> undercarriage smells of gasoline. I've taken it to my local mechanic
> > >> (not a jeep dealer) and he was unable to find the source of any leak.
> > >> I know my nose is not lying. Anyone have any ideas?
> > >>
>