Hi All,

I think the vacuum advance on my distributor is not working. I pulled the
cap/rotor and the cover under these off. I sucked on the vacuum line and
checked the linkage on the advance. It does move. I'm wondering if my
suction line off the carb is not suppling enough suction? or could the
advance still be bad even though the linkage moves?

'75 CJ5 258 1BBl carter

Thanks again,

Paul

 

You really need a timing light to tell what is going on for sure, but a
visual on the advance linkage outside the bottom of the distributor cap
will give you an idea.

Depending on your plumbing, the vacuum advance will do one of two
things. First it will do nothing at idle and advance as you give it gas
Or, it will go full advance at idle and back off when you give it gas to
a point, then slowly climb back up.

Looking at/ watching the linkage with it running will tell you.

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

Paul Brogren wrote:
>
> Hi All,
>
> I think the vacuum advance on my distributor is not working. I pulled the
> cap/rotor and the cover under these off. I sucked on the vacuum line and
> checked the linkage on the advance. It does move. I'm wondering if my
> suction line off the carb is not suppling enough suction? or could the
> advance still be bad even though the linkage moves?
>
> '75 CJ5 258 1BBl carter
>
> Thanks again,
>
> Paul

 

You really need a timing light to tell what is going on for sure, but a
visual on the advance linkage outside the bottom of the distributor cap
will give you an idea.

Depending on your plumbing, the vacuum advance will do one of two
things. First it will do nothing at idle and advance as you give it gas
Or, it will go full advance at idle and back off when you give it gas to
a point, then slowly climb back up.

Looking at/ watching the linkage with it running will tell you.

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

Paul Brogren wrote:
>
> Hi All,
>
> I think the vacuum advance on my distributor is not working. I pulled the
> cap/rotor and the cover under these off. I sucked on the vacuum line and
> checked the linkage on the advance. It does move. I'm wondering if my
> suction line off the carb is not suppling enough suction? or could the
> advance still be bad even though the linkage moves?
>
> '75 CJ5 258 1BBl carter
>
> Thanks again,
>
> Paul

 

You really need a timing light to tell what is going on for sure, but a
visual on the advance linkage outside the bottom of the distributor cap
will give you an idea.

Depending on your plumbing, the vacuum advance will do one of two
things. First it will do nothing at idle and advance as you give it gas
Or, it will go full advance at idle and back off when you give it gas to
a point, then slowly climb back up.

Looking at/ watching the linkage with it running will tell you.

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

Paul Brogren wrote:
>
> Hi All,
>
> I think the vacuum advance on my distributor is not working. I pulled the
> cap/rotor and the cover under these off. I sucked on the vacuum line and
> checked the linkage on the advance. It does move. I'm wondering if my
> suction line off the carb is not suppling enough suction? or could the
> advance still be bad even though the linkage moves?
>
> '75 CJ5 258 1BBl carter
>
> Thanks again,
>
> Paul

 

12 deg is up there, but within the limits. I run mine at 9.

You have two kinds of advance, one is a set of weights that slowly
climbs up, the other is vacuum that gives an instant jump.

I have mine set to ported vacuum, so the advance moves instantly with
the gas pedal.

I can 'hear' it snap to full advance inside the distributor when I give
it a quick shot of gas.

My distributor has the linkage going to the vacuum pot out in the open
on the front side of the distributor, I guess yours has a cover on it?

If you disconnect the vacuum line at the distributor with the engine
running does anything happen? If no, then it is a ported vacuum like
mine that does nothing at idle. Mine comes off the nipple on the valve
cover side of the carb up near the top.

You also should be able to have it idling and be able to suck on the
vacuum line and see the timing mark move with the light on it.

The mark also should move under the light way differently with the
vacuum line off. It will climb slow with the line of and just snap to
attention with a shot from the gas pedal with the line on.

Mike

Paul Brogren wrote:
>
> I've put a timing light on it. The timing is set at 12 deg. btdc. As I
> give it gas, the climbs 14, 15 on up until I can't even see the mark
> anymore. As far as looking at the linkage when it's running, I don't know
> if I can? The distributor doesn't have any visible linkage or clear parts.
> The advance is white plastic. The linkage I've looked at is under the rotor
> and within this white plastic housing. I'll bring a mirror out and see if
> there is anything I can see from undernearth the distributor itself maybe
> just above where it mounts down to the block.
>
> Thanks
> Paul
> "Mike Romain" <romainm@sympatico.ca> wrote in message
> news:3F846E64.5C4B0478@sympatico.ca...
> > You really need a timing light to tell what is going on for sure, but a
> > visual on the advance linkage outside the bottom of the distributor cap
> > will give you an idea.
> >
> > Depending on your plumbing, the vacuum advance will do one of two
> > things. First it will do nothing at idle and advance as you give it gas
> > Or, it will go full advance at idle and back off when you give it gas to
> > a point, then slowly climb back up.
> >
> > Looking at/ watching the linkage with it running will tell you.
> >
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> >
> > Paul Brogren wrote:
> > >
> > > Hi All,
> > >
> > > I think the vacuum advance on my distributor is not working. I pulled
> the
> > > cap/rotor and the cover under these off. I sucked on the vacuum line
> and
> > > checked the linkage on the advance. It does move. I'm wondering if my
> > > suction line off the carb is not suppling enough suction? or could the
> > > advance still be bad even though the linkage moves?
> > >
> > > '75 CJ5 258 1BBl carter
> > >
> > > Thanks again,
> > >
> > > Paul

 

12 deg is up there, but within the limits. I run mine at 9.

You have two kinds of advance, one is a set of weights that slowly
climbs up, the other is vacuum that gives an instant jump.

I have mine set to ported vacuum, so the advance moves instantly with
the gas pedal.

I can 'hear' it snap to full advance inside the distributor when I give
it a quick shot of gas.

My distributor has the linkage going to the vacuum pot out in the open
on the front side of the distributor, I guess yours has a cover on it?

If you disconnect the vacuum line at the distributor with the engine
running does anything happen? If no, then it is a ported vacuum like
mine that does nothing at idle. Mine comes off the nipple on the valve
cover side of the carb up near the top.

You also should be able to have it idling and be able to suck on the
vacuum line and see the timing mark move with the light on it.

The mark also should move under the light way differently with the
vacuum line off. It will climb slow with the line of and just snap to
attention with a shot from the gas pedal with the line on.

Mike

Paul Brogren wrote:
>
> I've put a timing light on it. The timing is set at 12 deg. btdc. As I
> give it gas, the climbs 14, 15 on up until I can't even see the mark
> anymore. As far as looking at the linkage when it's running, I don't know
> if I can? The distributor doesn't have any visible linkage or clear parts.
> The advance is white plastic. The linkage I've looked at is under the rotor
> and within this white plastic housing. I'll bring a mirror out and see if
> there is anything I can see from undernearth the distributor itself maybe
> just above where it mounts down to the block.
>
> Thanks
> Paul
> "Mike Romain" <romainm@sympatico.ca> wrote in message
> news:3F846E64.5C4B0478@sympatico.ca...
> > You really need a timing light to tell what is going on for sure, but a
> > visual on the advance linkage outside the bottom of the distributor cap
> > will give you an idea.
> >
> > Depending on your plumbing, the vacuum advance will do one of two
> > things. First it will do nothing at idle and advance as you give it gas
> > Or, it will go full advance at idle and back off when you give it gas to
> > a point, then slowly climb back up.
> >
> > Looking at/ watching the linkage with it running will tell you.
> >
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> >
> > Paul Brogren wrote:
> > >
> > > Hi All,
> > >
> > > I think the vacuum advance on my distributor is not working. I pulled
> the
> > > cap/rotor and the cover under these off. I sucked on the vacuum line
> and
> > > checked the linkage on the advance. It does move. I'm wondering if my
> > > suction line off the carb is not suppling enough suction? or could the
> > > advance still be bad even though the linkage moves?
> > >
> > > '75 CJ5 258 1BBl carter
> > >
> > > Thanks again,
> > >
> > > Paul

 

12 deg is up there, but within the limits. I run mine at 9.

You have two kinds of advance, one is a set of weights that slowly
climbs up, the other is vacuum that gives an instant jump.

I have mine set to ported vacuum, so the advance moves instantly with
the gas pedal.

I can 'hear' it snap to full advance inside the distributor when I give
it a quick shot of gas.

My distributor has the linkage going to the vacuum pot out in the open
on the front side of the distributor, I guess yours has a cover on it?

If you disconnect the vacuum line at the distributor with the engine
running does anything happen? If no, then it is a ported vacuum like
mine that does nothing at idle. Mine comes off the nipple on the valve
cover side of the carb up near the top.

You also should be able to have it idling and be able to suck on the
vacuum line and see the timing mark move with the light on it.

The mark also should move under the light way differently with the
vacuum line off. It will climb slow with the line of and just snap to
attention with a shot from the gas pedal with the line on.

Mike

Paul Brogren wrote:
>
> I've put a timing light on it. The timing is set at 12 deg. btdc. As I
> give it gas, the climbs 14, 15 on up until I can't even see the mark
> anymore. As far as looking at the linkage when it's running, I don't know
> if I can? The distributor doesn't have any visible linkage or clear parts.
> The advance is white plastic. The linkage I've looked at is under the rotor
> and within this white plastic housing. I'll bring a mirror out and see if
> there is anything I can see from undernearth the distributor itself maybe
> just above where it mounts down to the block.
>
> Thanks
> Paul
> "Mike Romain" <romainm@sympatico.ca> wrote in message
> news:3F846E64.5C4B0478@sympatico.ca...
> > You really need a timing light to tell what is going on for sure, but a
> > visual on the advance linkage outside the bottom of the distributor cap
> > will give you an idea.
> >
> > Depending on your plumbing, the vacuum advance will do one of two
> > things. First it will do nothing at idle and advance as you give it gas
> > Or, it will go full advance at idle and back off when you give it gas to
> > a point, then slowly climb back up.
> >
> > Looking at/ watching the linkage with it running will tell you.
> >
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> >
> > Paul Brogren wrote:
> > >
> > > Hi All,
> > >
> > > I think the vacuum advance on my distributor is not working. I pulled
> the
> > > cap/rotor and the cover under these off. I sucked on the vacuum line
> and
> > > checked the linkage on the advance. It does move. I'm wondering if my
> > > suction line off the carb is not suppling enough suction? or could the
> > > advance still be bad even though the linkage moves?
> > >
> > > '75 CJ5 258 1BBl carter
> > >
> > > Thanks again,
> > >
> > > Paul

 

I've put a timing light on it. The timing is set at 12 deg. btdc. As I
give it gas, the climbs 14, 15 on up until I can't even see the mark
anymore. As far as looking at the linkage when it's running, I don't know
if I can? The distributor doesn't have any visible linkage or clear parts.
The advance is white plastic. The linkage I've looked at is under the rotor
and within this white plastic housing. I'll bring a mirror out and see if
there is anything I can see from undernearth the distributor itself maybe
just above where it mounts down to the block.

Thanks
Paul
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:3F846E64.5C4B0478@sympatico.ca...
> You really need a timing light to tell what is going on for sure, but a
> visual on the advance linkage outside the bottom of the distributor cap
> will give you an idea.
>
> Depending on your plumbing, the vacuum advance will do one of two
> things. First it will do nothing at idle and advance as you give it gas
> Or, it will go full advance at idle and back off when you give it gas to
> a point, then slowly climb back up.
>
> Looking at/ watching the linkage with it running will tell you.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> Paul Brogren wrote:
> >
> > Hi All,
> >
> > I think the vacuum advance on my distributor is not working. I pulled
the
> > cap/rotor and the cover under these off. I sucked on the vacuum line
and
> > checked the linkage on the advance. It does move. I'm wondering if my
> > suction line off the carb is not suppling enough suction? or could the
> > advance still be bad even though the linkage moves?
> >
> > '75 CJ5 258 1BBl carter
> >
> > Thanks again,
> >
> > Paul

 

I've put a timing light on it. The timing is set at 12 deg. btdc. As I
give it gas, the climbs 14, 15 on up until I can't even see the mark
anymore. As far as looking at the linkage when it's running, I don't know
if I can? The distributor doesn't have any visible linkage or clear parts.
The advance is white plastic. The linkage I've looked at is under the rotor
and within this white plastic housing. I'll bring a mirror out and see if
there is anything I can see from undernearth the distributor itself maybe
just above where it mounts down to the block.

Thanks
Paul
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:3F846E64.5C4B0478@sympatico.ca...
> You really need a timing light to tell what is going on for sure, but a
> visual on the advance linkage outside the bottom of the distributor cap
> will give you an idea.
>
> Depending on your plumbing, the vacuum advance will do one of two
> things. First it will do nothing at idle and advance as you give it gas
> Or, it will go full advance at idle and back off when you give it gas to
> a point, then slowly climb back up.
>
> Looking at/ watching the linkage with it running will tell you.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> Paul Brogren wrote:
> >
> > Hi All,
> >
> > I think the vacuum advance on my distributor is not working. I pulled
the
> > cap/rotor and the cover under these off. I sucked on the vacuum line
and
> > checked the linkage on the advance. It does move. I'm wondering if my
> > suction line off the carb is not suppling enough suction? or could the
> > advance still be bad even though the linkage moves?
> >
> > '75 CJ5 258 1BBl carter
> >
> > Thanks again,
> >
> > Paul

 

I've put a timing light on it. The timing is set at 12 deg. btdc. As I
give it gas, the climbs 14, 15 on up until I can't even see the mark
anymore. As far as looking at the linkage when it's running, I don't know
if I can? The distributor doesn't have any visible linkage or clear parts.
The advance is white plastic. The linkage I've looked at is under the rotor
and within this white plastic housing. I'll bring a mirror out and see if
there is anything I can see from undernearth the distributor itself maybe
just above where it mounts down to the block.

Thanks
Paul
"Mike Romain" <romainm@sympatico.ca> wrote in message
news:3F846E64.5C4B0478@sympatico.ca...
> You really need a timing light to tell what is going on for sure, but a
> visual on the advance linkage outside the bottom of the distributor cap
> will give you an idea.
>
> Depending on your plumbing, the vacuum advance will do one of two
> things. First it will do nothing at idle and advance as you give it gas
> Or, it will go full advance at idle and back off when you give it gas to
> a point, then slowly climb back up.
>
> Looking at/ watching the linkage with it running will tell you.
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> Paul Brogren wrote:
> >
> > Hi All,
> >
> > I think the vacuum advance on my distributor is not working. I pulled
the
> > cap/rotor and the cover under these off. I sucked on the vacuum line
and
> > checked the linkage on the advance. It does move. I'm wondering if my
> > suction line off the carb is not suppling enough suction? or could the
> > advance still be bad even though the linkage moves?
> >
> > '75 CJ5 258 1BBl carter
> >
> > Thanks again,
> >
> > Paul