Check Engine light: loose gas cap LOL!
 

I can't beleive it, I was getting intermittent Check Engine lights on my '91'
XJ. After reading this newsgroup I tried cranking down my gas cap a little more
and now no more Check Engine light. The thing I'm wondering is why does the
emissions system care if my gas cap isn't
completely tight? Is the fuel tank pressurized or something?
-Bill (remove "botizer" to reply via email)

Re: Check Engine light: loose gas cap LOL!
 

Fumes from the gasoline evaperating in the tank.

JoBo

"Wblane" <wblane@aol.combotizer> wrote in message
news:20040705010035.19192.00001177@mb-m06.aol.com...
> I can't beleive it, I was getting intermittent Check Engine lights on my '91'
> XJ. After reading this newsgroup I tried cranking down my gas cap a little
more
> and now no more Check Engine light. The thing I'm wondering is why does the
> emissions system care if my gas cap isn't
> completely tight? Is the fuel tank pressurized or something?
> -Bill (remove "botizer" to reply via email)

Re: Check Engine light: loose gas cap LOL!
 

Fumes from the gasoline evaperating in the tank.

JoBo

"Wblane" <wblane@aol.combotizer> wrote in message
news:20040705010035.19192.00001177@mb-m06.aol.com...
> I can't beleive it, I was getting intermittent Check Engine lights on my '91'
> XJ. After reading this newsgroup I tried cranking down my gas cap a little
more
> and now no more Check Engine light. The thing I'm wondering is why does the
> emissions system care if my gas cap isn't
> completely tight? Is the fuel tank pressurized or something?
> -Bill (remove "botizer" to reply via email)

Re: Check Engine light: loose gas cap LOL!
 

Fumes from the gasoline evaperating in the tank.

JoBo

"Wblane" <wblane@aol.combotizer> wrote in message
news:20040705010035.19192.00001177@mb-m06.aol.com...
> I can't beleive it, I was getting intermittent Check Engine lights on my '91'
> XJ. After reading this newsgroup I tried cranking down my gas cap a little
more
> and now no more Check Engine light. The thing I'm wondering is why does the
> emissions system care if my gas cap isn't
> completely tight? Is the fuel tank pressurized or something?
> -Bill (remove "botizer" to reply via email)

Re: Check Engine light: loose gas cap LOL!
 

Fumes from the gasoline evaperating in the tank.

JoBo

"Wblane" <wblane@aol.combotizer> wrote in message
news:20040705010035.19192.00001177@mb-m06.aol.com...
> I can't beleive it, I was getting intermittent Check Engine lights on my '91'
> XJ. After reading this newsgroup I tried cranking down my gas cap a little
more
> and now no more Check Engine light. The thing I'm wondering is why does the
> emissions system care if my gas cap isn't
> completely tight? Is the fuel tank pressurized or something?
> -Bill (remove "botizer" to reply via email)

Re: Check Engine light: loose gas cap LOL!
 

On 05 Jul 2004 05:00:35 GMT, wblane@aol.combotizer (Wblane) wrote:

>I can't beleive it, I was getting intermittent Check Engine lights on my '91'
>XJ. After reading this newsgroup I tried cranking down my gas cap a little more
>and now no more Check Engine light. The thing I'm wondering is why does the
>emissions system care if my gas cap isn't
>completely tight? Is the fuel tank pressurized or something?

Yes. There is a pressure sensor in the fuel line to the charcoal
cannister. If the vapor pressure is too low it will trigger the check
engine light. All modern cars and trucks have sealed gas caps, and
have for many years now.

Always check the cap first thing if you get a light and have no code
reader handy. It's a relatively common problem.

You may need a new cap assembly if this reoccurs.



John Davies
http://home.comcast.net/~johnedavies/
'96 Lexus LX450
'00 Audi A4 1.8T quattro
Spokane WA USA

Re: Check Engine light: loose gas cap LOL!
 

On 05 Jul 2004 05:00:35 GMT, wblane@aol.combotizer (Wblane) wrote:

>I can't beleive it, I was getting intermittent Check Engine lights on my '91'
>XJ. After reading this newsgroup I tried cranking down my gas cap a little more
>and now no more Check Engine light. The thing I'm wondering is why does the
>emissions system care if my gas cap isn't
>completely tight? Is the fuel tank pressurized or something?

Yes. There is a pressure sensor in the fuel line to the charcoal
cannister. If the vapor pressure is too low it will trigger the check
engine light. All modern cars and trucks have sealed gas caps, and
have for many years now.

Always check the cap first thing if you get a light and have no code
reader handy. It's a relatively common problem.

You may need a new cap assembly if this reoccurs.



John Davies
http://home.comcast.net/~johnedavies/
'96 Lexus LX450
'00 Audi A4 1.8T quattro
Spokane WA USA

Re: Check Engine light: loose gas cap LOL!
 

On 05 Jul 2004 05:00:35 GMT, wblane@aol.combotizer (Wblane) wrote:

>I can't beleive it, I was getting intermittent Check Engine lights on my '91'
>XJ. After reading this newsgroup I tried cranking down my gas cap a little more
>and now no more Check Engine light. The thing I'm wondering is why does the
>emissions system care if my gas cap isn't
>completely tight? Is the fuel tank pressurized or something?

Yes. There is a pressure sensor in the fuel line to the charcoal
cannister. If the vapor pressure is too low it will trigger the check
engine light. All modern cars and trucks have sealed gas caps, and
have for many years now.

Always check the cap first thing if you get a light and have no code
reader handy. It's a relatively common problem.

You may need a new cap assembly if this reoccurs.



John Davies
http://home.comcast.net/~johnedavies/
'96 Lexus LX450
'00 Audi A4 1.8T quattro
Spokane WA USA

Re: Check Engine light: loose gas cap LOL!
 

On 05 Jul 2004 05:00:35 GMT, wblane@aol.combotizer (Wblane) wrote:

>I can't beleive it, I was getting intermittent Check Engine lights on my '91'
>XJ. After reading this newsgroup I tried cranking down my gas cap a little more
>and now no more Check Engine light. The thing I'm wondering is why does the
>emissions system care if my gas cap isn't
>completely tight? Is the fuel tank pressurized or something?

Yes. There is a pressure sensor in the fuel line to the charcoal
cannister. If the vapor pressure is too low it will trigger the check
engine light. All modern cars and trucks have sealed gas caps, and
have for many years now.

Always check the cap first thing if you get a light and have no code
reader handy. It's a relatively common problem.

You may need a new cap assembly if this reoccurs.



John Davies
http://home.comcast.net/~johnedavies/
'96 Lexus LX450
'00 Audi A4 1.8T quattro
Spokane WA USA

Re: Check Engine light: loose gas cap LOL!
 

Better keep looking for the cause of that Check Engine light. A 1991 XJ
couldn't care less if you took the gas cap off and threw it away.

Jeep didn't start monitoring the evap system until 1996, when OBD II was
implemented.


In message <20040705010035.19192.00001177@mb-m06.aol.com>, "Wblane" wrote:

>I can't beleive it, I was getting intermittent Check Engine lights on my '91'
>XJ. After reading this newsgroup I tried cranking down my gas cap a little more
>and now no more Check Engine light. The thing I'm wondering is why does the
>emissions system care if my gas cap isn't
>completely tight? Is the fuel tank pressurized or something?
>-Bill (remove "botizer" to reply via email)