Mike Romain

Not on a CJ7 unless your charcoal canister is crapped out.

There is an air filter on the bottom of the canister that can get dirty
which will put a vacuum on the gas tank.

A CJ tank is supposed to be at atmospheric pressure.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

William Oliveri wrote:
>
> Does the gas cap on a vehicle (jeep) have anything to do with Fuel Pressure?
>
> Thanks,
>
> Bill

Mike Romain

Not on a CJ7 unless your charcoal canister is crapped out.

There is an air filter on the bottom of the canister that can get dirty
which will put a vacuum on the gas tank.

A CJ tank is supposed to be at atmospheric pressure.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

William Oliveri wrote:
>
> Does the gas cap on a vehicle (jeep) have anything to do with Fuel Pressure?
>
> Thanks,
>
> Bill

Cherokee-LTD

Not so, in my case.
My Father had an '89 Trans Am GTA and it started running rough. He had it in
for service, they did whatever they did to it and told him all was well.
Within 20 minutes of leaving the shop it started acting up again... back to
the shop. They did some more work to it, said it was ready... 20 minutes
later it was acting up... back to the shop. My Father told them he wasn't
coming back for it- fix and deliver or keep it (company lease). They ended
up delivering it a day or two later and were very apologetic... the car was
just months old and they hadn't though of the gas cap. I don't know how much
they spent on it (leasing company got the bills) but I would have loved to
see the expression on the SM's face when they figured out it was a gas cap.

I had an '80 Monza... same problem except it wouldn't run at all. I went to
change the fuel pump, pulled the line off and heard a whoooosh. Put the line
back on, pulled the gas cap off and it ran well after a few cranks.

Depending on the capacity of the tank and venting/return lines you can get
pressure changes on both sides of the fuel pump. I'm not sure what Bill's
symptoms (or make/model) were but when he asks if a gas cap can effect fuel
pressure, I say absolutely.

-Brian

"Bob Casanova" <nospam@buzz.off> wrote in message
news:ljl0pvcphrtgni---42vkh2oli72vp9mgf@4ax.com...
: On Fri, 17 Oct 2003 20:00:02 GMT, the following appeared in
: rec.autos.makers.jeep+******, posted by "Cherokee-LTD"
: <spammenot@home.com>:
:
: ...but only the pressure in the tank.
:
: >Absolutely.
: >
: >"William Oliveri" <wuji@bigvalley.net> wrote in message
: >news:bmphg4$q2q18$1@ID-193866.news.uni-berlin.de...
: >: Does the gas cap on a vehicle (jeep) have anything to do with Fuel
: >Pressure?
: >:
: >:
: >: Thanks,
: >:
: >: Bill
: >:
: >:
: >
:
: --
:
: Bob C.
:
: Reply to Bob-Casanova @ worldnet.att.net
: (without the spaces, of course)
:
: "The most exciting phrase to hear in science,
: the one that heralds new discoveries, is not
: 'Eureka!' but 'That's funny...'"
: - Isaac Asimov

Cherokee-LTD

Not so, in my case.
My Father had an '89 Trans Am GTA and it started running rough. He had it in
for service, they did whatever they did to it and told him all was well.
Within 20 minutes of leaving the shop it started acting up again... back to
the shop. They did some more work to it, said it was ready... 20 minutes
later it was acting up... back to the shop. My Father told them he wasn't
coming back for it- fix and deliver or keep it (company lease). They ended
up delivering it a day or two later and were very apologetic... the car was
just months old and they hadn't though of the gas cap. I don't know how much
they spent on it (leasing company got the bills) but I would have loved to
see the expression on the SM's face when they figured out it was a gas cap.

I had an '80 Monza... same problem except it wouldn't run at all. I went to
change the fuel pump, pulled the line off and heard a whoooosh. Put the line
back on, pulled the gas cap off and it ran well after a few cranks.

Depending on the capacity of the tank and venting/return lines you can get
pressure changes on both sides of the fuel pump. I'm not sure what Bill's
symptoms (or make/model) were but when he asks if a gas cap can effect fuel
pressure, I say absolutely.

-Brian

"Bob Casanova" <nospam@buzz.off> wrote in message
news:ljl0pvcphrtgni---42vkh2oli72vp9mgf@4ax.com...
: On Fri, 17 Oct 2003 20:00:02 GMT, the following appeared in
: rec.autos.makers.jeep+******, posted by "Cherokee-LTD"
: <spammenot@home.com>:
:
: ...but only the pressure in the tank.
:
: >Absolutely.
: >
: >"William Oliveri" <wuji@bigvalley.net> wrote in message
: >news:bmphg4$q2q18$1@ID-193866.news.uni-berlin.de...
: >: Does the gas cap on a vehicle (jeep) have anything to do with Fuel
: >Pressure?
: >:
: >:
: >: Thanks,
: >:
: >: Bill
: >:
: >:
: >
:
: --
:
: Bob C.
:
: Reply to Bob-Casanova @ worldnet.att.net
: (without the spaces, of course)
:
: "The most exciting phrase to hear in science,
: the one that heralds new discoveries, is not
: 'Eureka!' but 'That's funny...'"
: - Isaac Asimov

Cherokee-LTD

Not so, in my case.
My Father had an '89 Trans Am GTA and it started running rough. He had it in
for service, they did whatever they did to it and told him all was well.
Within 20 minutes of leaving the shop it started acting up again... back to
the shop. They did some more work to it, said it was ready... 20 minutes
later it was acting up... back to the shop. My Father told them he wasn't
coming back for it- fix and deliver or keep it (company lease). They ended
up delivering it a day or two later and were very apologetic... the car was
just months old and they hadn't though of the gas cap. I don't know how much
they spent on it (leasing company got the bills) but I would have loved to
see the expression on the SM's face when they figured out it was a gas cap.

I had an '80 Monza... same problem except it wouldn't run at all. I went to
change the fuel pump, pulled the line off and heard a whoooosh. Put the line
back on, pulled the gas cap off and it ran well after a few cranks.

Depending on the capacity of the tank and venting/return lines you can get
pressure changes on both sides of the fuel pump. I'm not sure what Bill's
symptoms (or make/model) were but when he asks if a gas cap can effect fuel
pressure, I say absolutely.

-Brian

"Bob Casanova" <nospam@buzz.off> wrote in message
news:ljl0pvcphrtgni---42vkh2oli72vp9mgf@4ax.com...
: On Fri, 17 Oct 2003 20:00:02 GMT, the following appeared in
: rec.autos.makers.jeep+******, posted by "Cherokee-LTD"
: <spammenot@home.com>:
:
: ...but only the pressure in the tank.
:
: >Absolutely.
: >
: >"William Oliveri" <wuji@bigvalley.net> wrote in message
: >news:bmphg4$q2q18$1@ID-193866.news.uni-berlin.de...
: >: Does the gas cap on a vehicle (jeep) have anything to do with Fuel
: >Pressure?
: >:
: >:
: >: Thanks,
: >:
: >: Bill
: >:
: >:
: >
:
: --
:
: Bob C.
:
: Reply to Bob-Casanova @ worldnet.att.net
: (without the spaces, of course)
:
: "The most exciting phrase to hear in science,
: the one that heralds new discoveries, is not
: 'Eureka!' but 'That's funny...'"
: - Isaac Asimov

William Oliveri

Well, a new gas cap is 11.00 plus change. A cheap replacement to be sure.

bill

"Cherokee-LTD" <spammenot@home.com> wrote in message
news:VOZjb.368185$Lnr1.59047@news01.bloor.is.net.c able.rogers.com...
> Not so, in my case.
> My Father had an '89 Trans Am GTA and it started running rough. He had it
in
> for service, they did whatever they did to it and told him all was well.
> Within 20 minutes of leaving the shop it started acting up again... back
to
> the shop. They did some more work to it, said it was ready... 20 minutes
> later it was acting up... back to the shop. My Father told them he wasn't
> coming back for it- fix and deliver or keep it (company lease). They ended
> up delivering it a day or two later and were very apologetic... the car
was
> just months old and they hadn't though of the gas cap. I don't know how
much
> they spent on it (leasing company got the bills) but I would have loved to
> see the expression on the SM's face when they figured out it was a gas
cap.
>
> I had an '80 Monza... same problem except it wouldn't run at all. I went
to
> change the fuel pump, pulled the line off and heard a whoooosh. Put the
line
> back on, pulled the gas cap off and it ran well after a few cranks.
>
> Depending on the capacity of the tank and venting/return lines you can get
> pressure changes on both sides of the fuel pump. I'm not sure what Bill's
> symptoms (or make/model) were but when he asks if a gas cap can effect
fuel
> pressure, I say absolutely.
>
> -Brian
>
> "Bob Casanova" <nospam@buzz.off> wrote in message
> news:ljl0pvcphrtgni---42vkh2oli72vp9mgf@4ax.com...
> : On Fri, 17 Oct 2003 20:00:02 GMT, the following appeared in
> : rec.autos.makers.jeep+******, posted by "Cherokee-LTD"
> : <spammenot@home.com>:
> :
> : ...but only the pressure in the tank.
> :
> : >Absolutely.
> : >
> : >"William Oliveri" <wuji@bigvalley.net> wrote in message
> : >news:bmphg4$q2q18$1@ID-193866.news.uni-berlin.de...
> : >: Does the gas cap on a vehicle (jeep) have anything to do with Fuel
> : >Pressure?
> : >:
> : >:
> : >: Thanks,
> : >:
> : >: Bill
> : >:
> : >:
> : >
> :
> : --
> :
> : Bob C.
> :
> : Reply to Bob-Casanova @ worldnet.att.net
> : (without the spaces, of course)
> :
> : "The most exciting phrase to hear in science,
> : the one that heralds new discoveries, is not
> : 'Eureka!' but 'That's funny...'"
> : - Isaac Asimov
>
>

William Oliveri

Well, a new gas cap is 11.00 plus change. A cheap replacement to be sure.

bill

"Cherokee-LTD" <spammenot@home.com> wrote in message
news:VOZjb.368185$Lnr1.59047@news01.bloor.is.net.c able.rogers.com...
> Not so, in my case.
> My Father had an '89 Trans Am GTA and it started running rough. He had it
in
> for service, they did whatever they did to it and told him all was well.
> Within 20 minutes of leaving the shop it started acting up again... back
to
> the shop. They did some more work to it, said it was ready... 20 minutes
> later it was acting up... back to the shop. My Father told them he wasn't
> coming back for it- fix and deliver or keep it (company lease). They ended
> up delivering it a day or two later and were very apologetic... the car
was
> just months old and they hadn't though of the gas cap. I don't know how
much
> they spent on it (leasing company got the bills) but I would have loved to
> see the expression on the SM's face when they figured out it was a gas
cap.
>
> I had an '80 Monza... same problem except it wouldn't run at all. I went
to
> change the fuel pump, pulled the line off and heard a whoooosh. Put the
line
> back on, pulled the gas cap off and it ran well after a few cranks.
>
> Depending on the capacity of the tank and venting/return lines you can get
> pressure changes on both sides of the fuel pump. I'm not sure what Bill's
> symptoms (or make/model) were but when he asks if a gas cap can effect
fuel
> pressure, I say absolutely.
>
> -Brian
>
> "Bob Casanova" <nospam@buzz.off> wrote in message
> news:ljl0pvcphrtgni---42vkh2oli72vp9mgf@4ax.com...
> : On Fri, 17 Oct 2003 20:00:02 GMT, the following appeared in
> : rec.autos.makers.jeep+******, posted by "Cherokee-LTD"
> : <spammenot@home.com>:
> :
> : ...but only the pressure in the tank.
> :
> : >Absolutely.
> : >
> : >"William Oliveri" <wuji@bigvalley.net> wrote in message
> : >news:bmphg4$q2q18$1@ID-193866.news.uni-berlin.de...
> : >: Does the gas cap on a vehicle (jeep) have anything to do with Fuel
> : >Pressure?
> : >:
> : >:
> : >: Thanks,
> : >:
> : >: Bill
> : >:
> : >:
> : >
> :
> : --
> :
> : Bob C.
> :
> : Reply to Bob-Casanova @ worldnet.att.net
> : (without the spaces, of course)
> :
> : "The most exciting phrase to hear in science,
> : the one that heralds new discoveries, is not
> : 'Eureka!' but 'That's funny...'"
> : - Isaac Asimov
>
>

William Oliveri

Well, a new gas cap is 11.00 plus change. A cheap replacement to be sure.

bill

"Cherokee-LTD" <spammenot@home.com> wrote in message
news:VOZjb.368185$Lnr1.59047@news01.bloor.is.net.c able.rogers.com...
> Not so, in my case.
> My Father had an '89 Trans Am GTA and it started running rough. He had it
in
> for service, they did whatever they did to it and told him all was well.
> Within 20 minutes of leaving the shop it started acting up again... back
to
> the shop. They did some more work to it, said it was ready... 20 minutes
> later it was acting up... back to the shop. My Father told them he wasn't
> coming back for it- fix and deliver or keep it (company lease). They ended
> up delivering it a day or two later and were very apologetic... the car
was
> just months old and they hadn't though of the gas cap. I don't know how
much
> they spent on it (leasing company got the bills) but I would have loved to
> see the expression on the SM's face when they figured out it was a gas
cap.
>
> I had an '80 Monza... same problem except it wouldn't run at all. I went
to
> change the fuel pump, pulled the line off and heard a whoooosh. Put the
line
> back on, pulled the gas cap off and it ran well after a few cranks.
>
> Depending on the capacity of the tank and venting/return lines you can get
> pressure changes on both sides of the fuel pump. I'm not sure what Bill's
> symptoms (or make/model) were but when he asks if a gas cap can effect
fuel
> pressure, I say absolutely.
>
> -Brian
>
> "Bob Casanova" <nospam@buzz.off> wrote in message
> news:ljl0pvcphrtgni---42vkh2oli72vp9mgf@4ax.com...
> : On Fri, 17 Oct 2003 20:00:02 GMT, the following appeared in
> : rec.autos.makers.jeep+******, posted by "Cherokee-LTD"
> : <spammenot@home.com>:
> :
> : ...but only the pressure in the tank.
> :
> : >Absolutely.
> : >
> : >"William Oliveri" <wuji@bigvalley.net> wrote in message
> : >news:bmphg4$q2q18$1@ID-193866.news.uni-berlin.de...
> : >: Does the gas cap on a vehicle (jeep) have anything to do with Fuel
> : >Pressure?
> : >:
> : >:
> : >: Thanks,
> : >:
> : >: Bill
> : >:
> : >:
> : >
> :
> : --
> :
> : Bob C.
> :
> : Reply to Bob-Casanova @ worldnet.att.net
> : (without the spaces, of course)
> :
> : "The most exciting phrase to hear in science,
> : the one that heralds new discoveries, is not
> : 'Eureka!' but 'That's funny...'"
> : - Isaac Asimov
>
>

Bob Casanova

On Fri, 17 Oct 2003 22:12:05 GMT, the following appeared in
rec.autos.makers.jeep+******, posted by "Cherokee-LTD"
<spammenot@home.com>:

Thanks for the info. This is the first time I've heard of
this problem.

>Not so, in my case.
>My Father had an '89 Trans Am GTA and it started running rough. He had it in
>for service, they did whatever they did to it and told him all was well.
>Within 20 minutes of leaving the shop it started acting up again... back to
>the shop. They did some more work to it, said it was ready... 20 minutes
>later it was acting up... back to the shop. My Father told them he wasn't
>coming back for it- fix and deliver or keep it (company lease). They ended
>up delivering it a day or two later and were very apologetic... the car was
>just months old and they hadn't though of the gas cap. I don't know how much
>they spent on it (leasing company got the bills) but I would have loved to
>see the expression on the SM's face when they figured out it was a gas cap.
>
>I had an '80 Monza... same problem except it wouldn't run at all. I went to
>change the fuel pump, pulled the line off and heard a whoooosh. Put the line
>back on, pulled the gas cap off and it ran well after a few cranks.
>
>Depending on the capacity of the tank and venting/return lines you can get
>pressure changes on both sides of the fuel pump. I'm not sure what Bill's
>symptoms (or make/model) were but when he asks if a gas cap can effect fuel
>pressure, I say absolutely.
>
>-Brian
>
>"Bob Casanova" <nospam@buzz.off> wrote in message
>news:ljl0pvcphrtgni---42vkh2oli72vp9mgf@4ax.com.. .
>: On Fri, 17 Oct 2003 20:00:02 GMT, the following appeared in
>: rec.autos.makers.jeep+******, posted by "Cherokee-LTD"
>: <spammenot@home.com>:
>:
>: ...but only the pressure in the tank.
>:
>: >Absolutely.
>: >
>: >"William Oliveri" <wuji@bigvalley.net> wrote in message
>: >news:bmphg4$q2q18$1@ID-193866.news.uni-berlin.de...
>: >: Does the gas cap on a vehicle (jeep) have anything to do with Fuel
>: >Pressure?
>: >:
>: >:
>: >: Thanks,
>: >:
>: >: Bill
>: >:
>: >:
>: >
>:
>: --
>:
>: Bob C.
>:
>: Reply to Bob-Casanova @ worldnet.att.net
>: (without the spaces, of course)
>:
>: "The most exciting phrase to hear in science,
>: the one that heralds new discoveries, is not
>: 'Eureka!' but 'That's funny...'"
>: - Isaac Asimov
>

--

Bob C.

Reply to Bob-Casanova @ worldnet.att.net
(without the spaces, of course)

"The most exciting phrase to hear in science,
the one that heralds new discoveries, is not
'Eureka!' but 'That's funny...'"
- Isaac Asimov

Bob Casanova

On Fri, 17 Oct 2003 22:12:05 GMT, the following appeared in
rec.autos.makers.jeep+******, posted by "Cherokee-LTD"
<spammenot@home.com>:

Thanks for the info. This is the first time I've heard of
this problem.

>Not so, in my case.
>My Father had an '89 Trans Am GTA and it started running rough. He had it in
>for service, they did whatever they did to it and told him all was well.
>Within 20 minutes of leaving the shop it started acting up again... back to
>the shop. They did some more work to it, said it was ready... 20 minutes
>later it was acting up... back to the shop. My Father told them he wasn't
>coming back for it- fix and deliver or keep it (company lease). They ended
>up delivering it a day or two later and were very apologetic... the car was
>just months old and they hadn't though of the gas cap. I don't know how much
>they spent on it (leasing company got the bills) but I would have loved to
>see the expression on the SM's face when they figured out it was a gas cap.
>
>I had an '80 Monza... same problem except it wouldn't run at all. I went to
>change the fuel pump, pulled the line off and heard a whoooosh. Put the line
>back on, pulled the gas cap off and it ran well after a few cranks.
>
>Depending on the capacity of the tank and venting/return lines you can get
>pressure changes on both sides of the fuel pump. I'm not sure what Bill's
>symptoms (or make/model) were but when he asks if a gas cap can effect fuel
>pressure, I say absolutely.
>
>-Brian
>
>"Bob Casanova" <nospam@buzz.off> wrote in message
>news:ljl0pvcphrtgni---42vkh2oli72vp9mgf@4ax.com.. .
>: On Fri, 17 Oct 2003 20:00:02 GMT, the following appeared in
>: rec.autos.makers.jeep+******, posted by "Cherokee-LTD"
>: <spammenot@home.com>:
>:
>: ...but only the pressure in the tank.
>:
>: >Absolutely.
>: >
>: >"William Oliveri" <wuji@bigvalley.net> wrote in message
>: >news:bmphg4$q2q18$1@ID-193866.news.uni-berlin.de...
>: >: Does the gas cap on a vehicle (jeep) have anything to do with Fuel
>: >Pressure?
>: >:
>: >:
>: >: Thanks,
>: >:
>: >: Bill
>: >:
>: >:
>: >
>:
>: --
>:
>: Bob C.
>:
>: Reply to Bob-Casanova @ worldnet.att.net
>: (without the spaces, of course)
>:
>: "The most exciting phrase to hear in science,
>: the one that heralds new discoveries, is not
>: 'Eureka!' but 'That's funny...'"
>: - Isaac Asimov
>

--

Bob C.

Reply to Bob-Casanova @ worldnet.att.net
(without the spaces, of course)

"The most exciting phrase to hear in science,
the one that heralds new discoveries, is not
'Eureka!' but 'That's funny...'"
- Isaac Asimov