Smooth driver
 

While crossing Pennsylvania last week in my 2000 TJ, I found my gas
cap sitting on top of my tail light when I stopped to fill up. Over
100 miles at freeway speeds, the cap remained on the tail light;
however, the check engine light did not illuminate.

It should have?

Re: Smooth driver
 

Matt Osborn did pass the time by typing:
> While crossing Pennsylvania last week in my 2000 TJ, I found my gas
> cap sitting on top of my tail light when I stopped to fill up. Over
> 100 miles at freeway speeds, the cap remained on the tail light;
> however, the check engine light did not illuminate.

I did that with a mug of coffee. Only problem is I found it the
second the jeep came to a stop. :) The mug was almost "spillproof".

> It should have?

Dunno. Usually you get a code thrown for extended idle with a cap
off but it's not a 100% thing. Just something I've seen on jeeps
that used an aftermarket locking cap that didn't seal.

There isn't a specific fault code either. It usually manifests as
(fuel evaporator system) on a scantool. But IIRC it's a mix of
TPS, O2, and MAP sensors since there isn't a specific sensor for
the evap system.

--
DougW

Re: Smooth driver
 

Matt Osborn did pass the time by typing:
> While crossing Pennsylvania last week in my 2000 TJ, I found my gas
> cap sitting on top of my tail light when I stopped to fill up. Over
> 100 miles at freeway speeds, the cap remained on the tail light;
> however, the check engine light did not illuminate.

I did that with a mug of coffee. Only problem is I found it the
second the jeep came to a stop. :) The mug was almost "spillproof".

> It should have?

Dunno. Usually you get a code thrown for extended idle with a cap
off but it's not a 100% thing. Just something I've seen on jeeps
that used an aftermarket locking cap that didn't seal.

There isn't a specific fault code either. It usually manifests as
(fuel evaporator system) on a scantool. But IIRC it's a mix of
TPS, O2, and MAP sensors since there isn't a specific sensor for
the evap system.

--
DougW

Re: Smooth driver
 

Matt Osborn did pass the time by typing:
> While crossing Pennsylvania last week in my 2000 TJ, I found my gas
> cap sitting on top of my tail light when I stopped to fill up. Over
> 100 miles at freeway speeds, the cap remained on the tail light;
> however, the check engine light did not illuminate.

I did that with a mug of coffee. Only problem is I found it the
second the jeep came to a stop. :) The mug was almost "spillproof".

> It should have?

Dunno. Usually you get a code thrown for extended idle with a cap
off but it's not a 100% thing. Just something I've seen on jeeps
that used an aftermarket locking cap that didn't seal.

There isn't a specific fault code either. It usually manifests as
(fuel evaporator system) on a scantool. But IIRC it's a mix of
TPS, O2, and MAP sensors since there isn't a specific sensor for
the evap system.

--
DougW

Re: Smooth driver
 

Wow, lucky you! I think mine would have fallen off simply by idling my '85
CJ7.

I'd think your light would have come on, especially on a newer TJ ...but who
knows. Since when has anything relating to gas/gas tanks/gas gauges ever
read accurately on a Jeep? ;p

<Matt Osborn> wrote in message
news:otjsk0h45kps6rl3kd2ojrt37avrfnb178@4ax.com...
> While crossing Pennsylvania last week in my 2000 TJ, I found my gas
> cap sitting on top of my tail light when I stopped to fill up. Over
> 100 miles at freeway speeds, the cap remained on the tail light;
> however, the check engine light did not illuminate.
>
> It should have?

Re: Smooth driver
 

Wow, lucky you! I think mine would have fallen off simply by idling my '85
CJ7.

I'd think your light would have come on, especially on a newer TJ ...but who
knows. Since when has anything relating to gas/gas tanks/gas gauges ever
read accurately on a Jeep? ;p

<Matt Osborn> wrote in message
news:otjsk0h45kps6rl3kd2ojrt37avrfnb178@4ax.com...
> While crossing Pennsylvania last week in my 2000 TJ, I found my gas
> cap sitting on top of my tail light when I stopped to fill up. Over
> 100 miles at freeway speeds, the cap remained on the tail light;
> however, the check engine light did not illuminate.
>
> It should have?

Re: Smooth driver
 

Wow, lucky you! I think mine would have fallen off simply by idling my '85
CJ7.

I'd think your light would have come on, especially on a newer TJ ...but who
knows. Since when has anything relating to gas/gas tanks/gas gauges ever
read accurately on a Jeep? ;p

<Matt Osborn> wrote in message
news:otjsk0h45kps6rl3kd2ojrt37avrfnb178@4ax.com...
> While crossing Pennsylvania last week in my 2000 TJ, I found my gas
> cap sitting on top of my tail light when I stopped to fill up. Over
> 100 miles at freeway speeds, the cap remained on the tail light;
> however, the check engine light did not illuminate.
>
> It should have?

Re: Smooth driver
 

In message <otjsk0h45kps6rl3kd2ojrt37avrfnb178@4ax.com>, "Matt Osborn" wrote:

>While crossing Pennsylvania last week in my 2000 TJ, I found my gas
>cap sitting on top of my tail light when I stopped to fill up. Over
>100 miles at freeway speeds, the cap remained on the tail light;
>however, the check engine light did not illuminate.
>
>It should have?

No.

The evap system monitor only runs after a cold start, and it has to fail two
consecutive tests before the MIL is illuminated.

Re: Smooth driver
 

In message <otjsk0h45kps6rl3kd2ojrt37avrfnb178@4ax.com>, "Matt Osborn" wrote:

>While crossing Pennsylvania last week in my 2000 TJ, I found my gas
>cap sitting on top of my tail light when I stopped to fill up. Over
>100 miles at freeway speeds, the cap remained on the tail light;
>however, the check engine light did not illuminate.
>
>It should have?

No.

The evap system monitor only runs after a cold start, and it has to fail two
consecutive tests before the MIL is illuminated.

Re: Smooth driver
 

In message <otjsk0h45kps6rl3kd2ojrt37avrfnb178@4ax.com>, "Matt Osborn" wrote:

>While crossing Pennsylvania last week in my 2000 TJ, I found my gas
>cap sitting on top of my tail light when I stopped to fill up. Over
>100 miles at freeway speeds, the cap remained on the tail light;
>however, the check engine light did not illuminate.
>
>It should have?

No.

The evap system monitor only runs after a cold start, and it has to fail two
consecutive tests before the MIL is illuminated.