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'79 CJ5 gasline question.



 
 
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  #1  
Old April 9th 06, 07:40 PM posted to rec.autos.makers.jeep+willys
external usenet poster
 
Posts: n/a
Default '79 CJ5 gasline question.

Hi all,

it seems that if my '79 CJ5 is sitting for a while that the gas
runs through the line back to the tank.

That means that after it has been sitting for a while. I have to crank
it for a while before it starts. (if it sits for a day or so.. I have
to crank it quite a bit. If it sits there for an hour or 2 there's no
problem

I replaced all the hoses.

How does the gascap work ? is it supposed to seal the gastank,
or doesn't it matter ? The gascap I have is probably the original.


thanks,

Ron
Ads
  #2  
Old April 9th 06, 09:38 PM posted to rec.autos.makers.jeep+willys
external usenet poster
 
Posts: n/a
Default '79 CJ5 gasline question.

That usually happens because the gas filter is in upside down. The
filter has two outlets, the center outlet leads to the carb and the
'top' one leads to the return line. If the return line isn't at the
top, gas will syphon back to the tank air locking the line and they are
real buggers to start up.

There also is a valve on the fuel pump likely to stop backflow. You
could first make sure the filter is right, then take the line off the
pump intake to see if the gas all comes out.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)


Ron Croonenberg wrote:
>
> Hi all,
>
> it seems that if my '79 CJ5 is sitting for a while that the gas
> runs through the line back to the tank.
>
> That means that after it has been sitting for a while. I have to crank
> it for a while before it starts. (if it sits for a day or so.. I have
> to crank it quite a bit. If it sits there for an hour or 2 there's no
> problem
>
> I replaced all the hoses.
>
> How does the gascap work ? is it supposed to seal the gastank,
> or doesn't it matter ? The gascap I have is probably the original.
>
> thanks,
>
> Ron

  #3  
Old April 10th 06, 03:49 PM posted to rec.autos.makers.jeep+willys
external usenet poster
 
Posts: n/a
Default '79 CJ5 gasline question.

Ok, let me check that.

It always had that problem, also when I replaced the fuel pump.
I can check to see if the filter is upside down or not.

If it is the fuelfilter doing that, are there any better ones ? How do I
know I have the correct one ? (Is there a pic of one somewhere ?

Is there a "everything you wanted to ask about your CJ's fuel lines but
were afraid to ask" page somewhere ?



> That usually happens because the gas filter is in upside down. The
> filter has two outlets, the center outlet leads to the carb and the
> 'top' one leads to the return line. If the return line isn't at the
> top, gas will syphon back to the tank air locking the line and they are
> real buggers to start up.
>
> There also is a valve on the fuel pump likely to stop backflow. You
> could first make sure the filter is right, then take the line off the
> pump intake to see if the gas all comes out.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
> Canadian Off Road Trips Photos: Non members can still view!
> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> (More Off Road album links at bottom of the view page)
>
>
> Ron Croonenberg wrote:
>
>>Hi all,
>>
>>it seems that if my '79 CJ5 is sitting for a while that the gas
>>runs through the line back to the tank.
>>
>>That means that after it has been sitting for a while. I have to crank
>>it for a while before it starts. (if it sits for a day or so.. I have
>>to crank it quite a bit. If it sits there for an hour or 2 there's no
>>problem
>>
>>I replaced all the hoses.
>>
>>How does the gascap work ? is it supposed to seal the gastank,
>>or doesn't it matter ? The gascap I have is probably the original.
>>
>>thanks,
>>
>>Ron

  #4  
Old April 10th 06, 04:09 PM posted to rec.autos.makers.jeep+willys
external usenet poster
 
Posts: n/a
Default '79 CJ5 gasline question.

The parts stores around here all carry the CJ gas filter. The YJ up to
91 uses the same one. Once it is in place it won't rotate unless
bumped, but it 'is' easy to rotate if you are mucking about with the
carb.

I find the Haynes CJ manual to be a very good one. It covers pretty
much everything accurately.

The owners manual even mentions the right way to install the fuel
filter.

Mike

Ron Croonenberg wrote:
>
> Ok, let me check that.
>
> It always had that problem, also when I replaced the fuel pump.
> I can check to see if the filter is upside down or not.
>
> If it is the fuelfilter doing that, are there any better ones ? How do I
> know I have the correct one ? (Is there a pic of one somewhere ?
>
> Is there a "everything you wanted to ask about your CJ's fuel lines but
> were afraid to ask" page somewhere ?
>
> > That usually happens because the gas filter is in upside down. The
> > filter has two outlets, the center outlet leads to the carb and the
> > 'top' one leads to the return line. If the return line isn't at the
> > top, gas will syphon back to the tank air locking the line and they are
> > real buggers to start up.
> >
> > There also is a valve on the fuel pump likely to stop backflow. You
> > could first make sure the filter is right, then take the line off the
> > pump intake to see if the gas all comes out.
> >
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> > Canadian Off Road Trips Photos: Non members can still view!
> > Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> > (More Off Road album links at bottom of the view page)
> >
> >
> > Ron Croonenberg wrote:
> >
> >>Hi all,
> >>
> >>it seems that if my '79 CJ5 is sitting for a while that the gas
> >>runs through the line back to the tank.
> >>
> >>That means that after it has been sitting for a while. I have to crank
> >>it for a while before it starts. (if it sits for a day or so.. I have
> >>to crank it quite a bit. If it sits there for an hour or 2 there's no
> >>problem
> >>
> >>I replaced all the hoses.
> >>
> >>How does the gascap work ? is it supposed to seal the gastank,
> >>or doesn't it matter ? The gascap I have is probably the original.
> >>
> >>thanks,
> >>
> >>Ron

  #5  
Old April 10th 06, 09:54 PM posted to rec.autos.makers.jeep+willys
external usenet poster
 
Posts: n/a
Default '79 CJ5 gasline question.

I just checked the CJ the off center outlet is on top
I don't have the original carb anymore I have that weber one

Mike Romain wrote:

> The parts stores around here all carry the CJ gas filter. The YJ up to
> 91 uses the same one. Once it is in place it won't rotate unless
> bumped, but it 'is' easy to rotate if you are mucking about with the
> carb.
>
> I find the Haynes CJ manual to be a very good one. It covers pretty
> much everything accurately.
>
> The owners manual even mentions the right way to install the fuel
> filter.
>
> Mike
>
> Ron Croonenberg wrote:
>
>>Ok, let me check that.
>>
>>It always had that problem, also when I replaced the fuel pump.
>>I can check to see if the filter is upside down or not.
>>
>>If it is the fuelfilter doing that, are there any better ones ? How do I
>>know I have the correct one ? (Is there a pic of one somewhere ?
>>
>>Is there a "everything you wanted to ask about your CJ's fuel lines but
>>were afraid to ask" page somewhere ?
>>
>>
>>>That usually happens because the gas filter is in upside down. The
>>>filter has two outlets, the center outlet leads to the carb and the
>>>'top' one leads to the return line. If the return line isn't at the
>>>top, gas will syphon back to the tank air locking the line and they are
>>>real buggers to start up.
>>>
>>>There also is a valve on the fuel pump likely to stop backflow. You
>>>could first make sure the filter is right, then take the line off the
>>>pump intake to see if the gas all comes out.
>>>
>>>Mike
>>>86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>>>88 Cherokee 235 BFG AT's
>>>Canadian Off Road Trips Photos: Non members can still view!
>>>Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>>>(More Off Road album links at bottom of the view page)
>>>
>>>
>>>Ron Croonenberg wrote:
>>>
>>>
>>>>Hi all,
>>>>
>>>>it seems that if my '79 CJ5 is sitting for a while that the gas
>>>>runs through the line back to the tank.
>>>>
>>>>That means that after it has been sitting for a while. I have to crank
>>>>it for a while before it starts. (if it sits for a day or so.. I have
>>>>to crank it quite a bit. If it sits there for an hour or 2 there's no
>>>>problem
>>>>
>>>>I replaced all the hoses.
>>>>
>>>>How does the gascap work ? is it supposed to seal the gastank,
>>>>or doesn't it matter ? The gascap I have is probably the original.
>>>>
>>>>thanks,
>>>>
>>>>Ron

  #6  
Old April 10th 06, 10:08 PM posted to rec.autos.makers.jeep+willys
external usenet poster
 
Posts: n/a
Default '79 CJ5 gasline question.

The carb doesn't matter unless it won't run at the CJ carb's pressure
which is a different problem. It is just physics with the gas lines.
If the return is up top, gas won't syphon.

There was a thread back a while ago about the pressure that filter is
set for. Some place around 5 psi I think. It is set by the hole size
in the return line outlet. Lower pressure could be had by drilling out
the blocking plate.

Mike

Ron Croonenberg wrote:
>
> I just checked the CJ the off center outlet is on top
> I don't have the original carb anymore I have that weber one
>
> Mike Romain wrote:
>
> > The parts stores around here all carry the CJ gas filter. The YJ up to
> > 91 uses the same one. Once it is in place it won't rotate unless
> > bumped, but it 'is' easy to rotate if you are mucking about with the
> > carb.
> >
> > I find the Haynes CJ manual to be a very good one. It covers pretty
> > much everything accurately.
> >
> > The owners manual even mentions the right way to install the fuel
> > filter.
> >
> > Mike
> >
> > Ron Croonenberg wrote:
> >
> >>Ok, let me check that.
> >>
> >>It always had that problem, also when I replaced the fuel pump.
> >>I can check to see if the filter is upside down or not.
> >>
> >>If it is the fuelfilter doing that, are there any better ones ? How do I
> >>know I have the correct one ? (Is there a pic of one somewhere ?
> >>
> >>Is there a "everything you wanted to ask about your CJ's fuel lines but
> >>were afraid to ask" page somewhere ?
> >>
> >>
> >>>That usually happens because the gas filter is in upside down. The
> >>>filter has two outlets, the center outlet leads to the carb and the
> >>>'top' one leads to the return line. If the return line isn't at the
> >>>top, gas will syphon back to the tank air locking the line and they are
> >>>real buggers to start up.
> >>>
> >>>There also is a valve on the fuel pump likely to stop backflow. You
> >>>could first make sure the filter is right, then take the line off the
> >>>pump intake to see if the gas all comes out.
> >>>
> >>>Mike
> >>>86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> >>>88 Cherokee 235 BFG AT's
> >>>Canadian Off Road Trips Photos: Non members can still view!
> >>>Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> >>>(More Off Road album links at bottom of the view page)
> >>>
> >>>
> >>>Ron Croonenberg wrote:
> >>>
> >>>
> >>>>Hi all,
> >>>>
> >>>>it seems that if my '79 CJ5 is sitting for a while that the gas
> >>>>runs through the line back to the tank.
> >>>>
> >>>>That means that after it has been sitting for a while. I have to crank
> >>>>it for a while before it starts. (if it sits for a day or so.. I have
> >>>>to crank it quite a bit. If it sits there for an hour or 2 there's no
> >>>>problem
> >>>>
> >>>>I replaced all the hoses.
> >>>>
> >>>>How does the gascap work ? is it supposed to seal the gastank,
> >>>>or doesn't it matter ? The gascap I have is probably the original.
> >>>>
> >>>>thanks,
> >>>>
> >>>>Ron

  #7  
Old April 10th 06, 10:33 PM posted to rec.autos.makers.jeep+willys
external usenet poster
 
Posts: n/a
Default '79 CJ5 gasline question.

ok....

So if the return outlet is on top and the engine won't start (after a
day of sitting still) unless I crank it for 30 secs or so.. then what
could the problem ? To me it seems that it is acting like there's no fuel.

Mike Romain wrote:

> The carb doesn't matter unless it won't run at the CJ carb's pressure
> which is a different problem. It is just physics with the gas lines.
> If the return is up top, gas won't syphon.
>
> There was a thread back a while ago about the pressure that filter is
> set for. Some place around 5 psi I think. It is set by the hole size
> in the return line outlet. Lower pressure could be had by drilling out
> the blocking plate.
>
> Mike
>
> Ron Croonenberg wrote:
>
>>I just checked the CJ the off center outlet is on top
>>I don't have the original carb anymore I have that weber one
>>
>>Mike Romain wrote:
>>
>>
>>>The parts stores around here all carry the CJ gas filter. The YJ up to
>>>91 uses the same one. Once it is in place it won't rotate unless
>>>bumped, but it 'is' easy to rotate if you are mucking about with the
>>>carb.
>>>
>>>I find the Haynes CJ manual to be a very good one. It covers pretty
>>>much everything accurately.
>>>
>>>The owners manual even mentions the right way to install the fuel
>>>filter.
>>>
>>>Mike
>>>
>>>Ron Croonenberg wrote:
>>>
>>>
>>>>Ok, let me check that.
>>>>
>>>>It always had that problem, also when I replaced the fuel pump.
>>>>I can check to see if the filter is upside down or not.
>>>>
>>>>If it is the fuelfilter doing that, are there any better ones ? How do I
>>>>know I have the correct one ? (Is there a pic of one somewhere ?
>>>>
>>>>Is there a "everything you wanted to ask about your CJ's fuel lines but
>>>>were afraid to ask" page somewhere ?
>>>>
>>>>
>>>>
>>>>>That usually happens because the gas filter is in upside down. The
>>>>>filter has two outlets, the center outlet leads to the carb and the
>>>>>'top' one leads to the return line. If the return line isn't at the
>>>>>top, gas will syphon back to the tank air locking the line and they are
>>>>>real buggers to start up.
>>>>>
>>>>>There also is a valve on the fuel pump likely to stop backflow. You
>>>>>could first make sure the filter is right, then take the line off the
>>>>>pump intake to see if the gas all comes out.
>>>>>
>>>>>Mike
>>>>>86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>>>>>88 Cherokee 235 BFG AT's
>>>>>Canadian Off Road Trips Photos: Non members can still view!
>>>>>Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>>>>>(More Off Road album links at bottom of the view page)
>>>>>
>>>>>
>>>>>Ron Croonenberg wrote:
>>>>>
>>>>>
>>>>>
>>>>>>Hi all,
>>>>>>
>>>>>>it seems that if my '79 CJ5 is sitting for a while that the gas
>>>>>>runs through the line back to the tank.
>>>>>>
>>>>>>That means that after it has been sitting for a while. I have to crank
>>>>>>it for a while before it starts. (if it sits for a day or so.. I have
>>>>>>to crank it quite a bit. If it sits there for an hour or 2 there's no
>>>>>>problem
>>>>>>
>>>>>>I replaced all the hoses.
>>>>>>
>>>>>>How does the gascap work ? is it supposed to seal the gastank,
>>>>>>or doesn't it matter ? The gascap I have is probably the original.
>>>>>>
>>>>>>thanks,
>>>>>>
>>>>>>Ron

  #8  
Old April 10th 06, 11:18 PM posted to rec.autos.makers.jeep+willys
external usenet poster
 
Posts: n/a
Default '79 CJ5 gasline question.

Let's try that again.... ;-)

The center outlet of the filter goes to the carb. The return line needs
to be at the top of the filter on the smaller nipple. The two nipples
are different sizes.

Then when the carb is full, the gas raises to the top of the filter and
goes back the return line to the tank so the return line is up top.

This prevents vapor lock also because when you shut it down hot, gas can
boil in the line which causes the vapor lock and no start like you are
experiencing.

If the return line is down, then the gas is free to run back to the tank
which vapor locks it. It will then need two primes of a quarter cup of
gas for the pump to pick it up if you want to save your battery and
starter....

Mike


Ron Croonenberg wrote:
>
> ok....
>
> So if the return outlet is on top and the engine won't start (after a
> day of sitting still) unless I crank it for 30 secs or so.. then what
> could the problem ? To me it seems that it is acting like there's no fuel.
>
> Mike Romain wrote:
>
> > The carb doesn't matter unless it won't run at the CJ carb's pressure
> > which is a different problem. It is just physics with the gas lines.
> > If the return is up top, gas won't syphon.
> >
> > There was a thread back a while ago about the pressure that filter is
> > set for. Some place around 5 psi I think. It is set by the hole size
> > in the return line outlet. Lower pressure could be had by drilling out
> > the blocking plate.
> >
> > Mike
> >
> > Ron Croonenberg wrote:
> >
> >>I just checked the CJ the off center outlet is on top
> >>I don't have the original carb anymore I have that weber one
> >>
> >>Mike Romain wrote:
> >>
> >>
> >>>The parts stores around here all carry the CJ gas filter. The YJ up to
> >>>91 uses the same one. Once it is in place it won't rotate unless
> >>>bumped, but it 'is' easy to rotate if you are mucking about with the
> >>>carb.
> >>>
> >>>I find the Haynes CJ manual to be a very good one. It covers pretty
> >>>much everything accurately.
> >>>
> >>>The owners manual even mentions the right way to install the fuel
> >>>filter.
> >>>
> >>>Mike
> >>>
> >>>Ron Croonenberg wrote:
> >>>
> >>>
> >>>>Ok, let me check that.
> >>>>
> >>>>It always had that problem, also when I replaced the fuel pump.
> >>>>I can check to see if the filter is upside down or not.
> >>>>
> >>>>If it is the fuelfilter doing that, are there any better ones ? How do I
> >>>>know I have the correct one ? (Is there a pic of one somewhere ?
> >>>>
> >>>>Is there a "everything you wanted to ask about your CJ's fuel lines but
> >>>>were afraid to ask" page somewhere ?
> >>>>
> >>>>
> >>>>
> >>>>>That usually happens because the gas filter is in upside down. The
> >>>>>filter has two outlets, the center outlet leads to the carb and the
> >>>>>'top' one leads to the return line. If the return line isn't at the
> >>>>>top, gas will syphon back to the tank air locking the line and they are
> >>>>>real buggers to start up.
> >>>>>
> >>>>>There also is a valve on the fuel pump likely to stop backflow. You
> >>>>>could first make sure the filter is right, then take the line off the
> >>>>>pump intake to see if the gas all comes out.
> >>>>>
> >>>>>Mike
> >>>>>86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> >>>>>88 Cherokee 235 BFG AT's
> >>>>>Canadian Off Road Trips Photos: Non members can still view!
> >>>>>Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
> >>>>>(More Off Road album links at bottom of the view page)
> >>>>>
> >>>>>
> >>>>>Ron Croonenberg wrote:
> >>>>>
> >>>>>
> >>>>>
> >>>>>>Hi all,
> >>>>>>
> >>>>>>it seems that if my '79 CJ5 is sitting for a while that the gas
> >>>>>>runs through the line back to the tank.
> >>>>>>
> >>>>>>That means that after it has been sitting for a while. I have to crank
> >>>>>>it for a while before it starts. (if it sits for a day or so.. I have
> >>>>>>to crank it quite a bit. If it sits there for an hour or 2 there's no
> >>>>>>problem
> >>>>>>
> >>>>>>I replaced all the hoses.
> >>>>>>
> >>>>>>How does the gascap work ? is it supposed to seal the gastank,
> >>>>>>or doesn't it matter ? The gascap I have is probably the original.
> >>>>>>
> >>>>>>thanks,
> >>>>>>
> >>>>>>Ron

  #9  
Old April 11th 06, 12:28 AM posted to rec.autos.makers.jeep+willys
external usenet poster
 
Posts: n/a
Default '79 CJ5 gasline question.

Mike Romain did pass the time by typing:
> Let's try that again.... ;-)
>
> The center outlet of the filter goes to the carb. The return line needs
> to be at the top of the filter on the smaller nipple. The two nipples
> are different sizes.
>
> Then when the carb is full, the gas raises to the top of the filter and
> goes back the return line to the tank so the return line is up top.
>
> This prevents vapor lock also because when you shut it down hot, gas can
> boil in the line which causes the vapor lock and no start like you are
> experiencing.
>
> If the return line is down, then the gas is free to run back to the tank
> which vapor locks it. It will then need two primes of a quarter cup of
> gas for the pump to pick it up if you want to save your battery and
> starter....


Dunno if this applies but in the old rochester 4M4 quadrasuck there
was a fuel filter with built-in check valve right in the carb
Use the one without a check valve and it will drain back to the tank.

--
DougW


  #10  
Old April 11th 06, 12:37 AM posted to rec.autos.makers.jeep+willys
external usenet poster
 
Posts: n/a
Default '79 CJ5 gasline question.

DougW wrote:
>
> Mike Romain did pass the time by typing:
> > Let's try that again.... ;-)
> >
> > The center outlet of the filter goes to the carb. The return line needs
> > to be at the top of the filter on the smaller nipple. The two nipples
> > are different sizes.
> >
> > Then when the carb is full, the gas raises to the top of the filter and
> > goes back the return line to the tank so the return line is up top.
> >
> > This prevents vapor lock also because when you shut it down hot, gas can
> > boil in the line which causes the vapor lock and no start like you are
> > experiencing.
> >
> > If the return line is down, then the gas is free to run back to the tank
> > which vapor locks it. It will then need two primes of a quarter cup of
> > gas for the pump to pick it up if you want to save your battery and
> > starter....

>
> Dunno if this applies but in the old rochester 4M4 quadrasuck there
> was a fuel filter with built-in check valve right in the carb
> Use the one without a check valve and it will drain back to the tank.
>
> --
> DougW


Jeep figured the external filter with the return line was a better
option I guess, but it is the same idea. Vapor lock is an issue on the
I6 because the gas line runs up over top of the valve cover and across
the manifolds. The return line was the fix.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)
 




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