CJ5 misfires at high RPM/hard acceleration
07-18-2007, 11:46 PM
#161
Guest
Posts: n/a
Re: CJ5 misfires at high RPM/hard acceleration
great advice carl, maybe next time you'll think of something the idiots at
car quest wouldn't recomend
Carl S wrote:
>If the plugs are just fouled, I would pull them out and clean them up with
>some light brushing and some B-12chemtool. Re-gap, re-install, and see if
>that helps.
>
>Carl
>
>> Gentlemen,
>>
>[quoted text clipped - 66 lines]
>>
>> -Matt
--
Message posted via http://www.carkb.com
car quest wouldn't recomend
Carl S wrote:
>If the plugs are just fouled, I would pull them out and clean them up with
>some light brushing and some B-12chemtool. Re-gap, re-install, and see if
>that helps.
>
>Carl
>
>> Gentlemen,
>>
>[quoted text clipped - 66 lines]
>>
>> -Matt
--
Message posted via http://www.carkb.com
07-19-2007, 12:42 AM
#162
Guest
Posts: n/a
Re: CJ5 misfires at high RPM/hard acceleration
here here Bill, Here here
+1
Bill Spiliotopoulos wrote:
>As I said I don't have any experience on Holley carburators or CJ5s.
>I have woked on Webers and Solexes, carbs with no separate throttle base,
>and with ported vacum for the advance.
>
>Anyway, if he has a manifold vacuum and not ported vacum signal for the
>advance, then the centrifugal advance mechanism plays a more significant
>role and will cause more noticeable problems (similar to the ones the OP
>has) if it doesn't work.
>In the case of manifold vacum signal the distrubutor is timed with less
>static advance (the advance measured @idle with vacum disconected), so that
>the advance is at acceptable limits when the engine idles were it has full
>vacum advance.
>When the engine revs above 2800-3000 rpm, it needs about 28 degrees of
>advance at full throttle, provided by the centrifugal advance mechanism. If
>this is not working, and because there is no vacum advance due to high load
>(weak manifold vacum), ending-up with a total advance close to zero degrees,
>as much as the static advance causing incomplete combustion, loss of power
>and backfiring.
>The simple test for the centrifugal advance mechanism is twisting the rotor
>and expect it to spring back, but a timing light with the vacuum advance
>disconected will show for sure if the centrifugal advance is working.
>
>About the idle speed setting using the butterfly, there are two cases:
>1) Carb with only a mixture adjusting screw, where you fine-tune the idle
>speed by adjusting the butterfly opening, after having set the mixture screw
>to the point that the idle speed is at its highest, just before it begins to
>drop.
>2) Carb with mixture and bypass screws, where the butterfly must be
>completelly closed and idle speed adjusted with the bypass screw, after the
>mixture screw is set correctly.
>
>Bill spiliotopoulos,
>'96 XJ, '06 TJ.
>
>>> Without having experience on your engine / carb /distributor, I can tell
>>> you what is usually the case.
>[quoted text clipped - 17 lines]
>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>> (More Off Road album links at bottom of the view page)
--
Message posted via CarKB.com
http://www.carkb.com/Uwe/Forums.aspx/jeep-cars/200707/1
+1
Bill Spiliotopoulos wrote:
>As I said I don't have any experience on Holley carburators or CJ5s.
>I have woked on Webers and Solexes, carbs with no separate throttle base,
>and with ported vacum for the advance.
>
>Anyway, if he has a manifold vacuum and not ported vacum signal for the
>advance, then the centrifugal advance mechanism plays a more significant
>role and will cause more noticeable problems (similar to the ones the OP
>has) if it doesn't work.
>In the case of manifold vacum signal the distrubutor is timed with less
>static advance (the advance measured @idle with vacum disconected), so that
>the advance is at acceptable limits when the engine idles were it has full
>vacum advance.
>When the engine revs above 2800-3000 rpm, it needs about 28 degrees of
>advance at full throttle, provided by the centrifugal advance mechanism. If
>this is not working, and because there is no vacum advance due to high load
>(weak manifold vacum), ending-up with a total advance close to zero degrees,
>as much as the static advance causing incomplete combustion, loss of power
>and backfiring.
>The simple test for the centrifugal advance mechanism is twisting the rotor
>and expect it to spring back, but a timing light with the vacuum advance
>disconected will show for sure if the centrifugal advance is working.
>
>About the idle speed setting using the butterfly, there are two cases:
>1) Carb with only a mixture adjusting screw, where you fine-tune the idle
>speed by adjusting the butterfly opening, after having set the mixture screw
>to the point that the idle speed is at its highest, just before it begins to
>drop.
>2) Carb with mixture and bypass screws, where the butterfly must be
>completelly closed and idle speed adjusted with the bypass screw, after the
>mixture screw is set correctly.
>
>Bill spiliotopoulos,
>'96 XJ, '06 TJ.
>
>>> Without having experience on your engine / carb /distributor, I can tell
>>> you what is usually the case.
>[quoted text clipped - 17 lines]
>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>> (More Off Road album links at bottom of the view page)
--
Message posted via CarKB.com
http://www.carkb.com/Uwe/Forums.aspx/jeep-cars/200707/1
07-19-2007, 12:42 AM
#163
Guest
Posts: n/a
Re: CJ5 misfires at high RPM/hard acceleration
here here Bill, Here here
+1
Bill Spiliotopoulos wrote:
>As I said I don't have any experience on Holley carburators or CJ5s.
>I have woked on Webers and Solexes, carbs with no separate throttle base,
>and with ported vacum for the advance.
>
>Anyway, if he has a manifold vacuum and not ported vacum signal for the
>advance, then the centrifugal advance mechanism plays a more significant
>role and will cause more noticeable problems (similar to the ones the OP
>has) if it doesn't work.
>In the case of manifold vacum signal the distrubutor is timed with less
>static advance (the advance measured @idle with vacum disconected), so that
>the advance is at acceptable limits when the engine idles were it has full
>vacum advance.
>When the engine revs above 2800-3000 rpm, it needs about 28 degrees of
>advance at full throttle, provided by the centrifugal advance mechanism. If
>this is not working, and because there is no vacum advance due to high load
>(weak manifold vacum), ending-up with a total advance close to zero degrees,
>as much as the static advance causing incomplete combustion, loss of power
>and backfiring.
>The simple test for the centrifugal advance mechanism is twisting the rotor
>and expect it to spring back, but a timing light with the vacuum advance
>disconected will show for sure if the centrifugal advance is working.
>
>About the idle speed setting using the butterfly, there are two cases:
>1) Carb with only a mixture adjusting screw, where you fine-tune the idle
>speed by adjusting the butterfly opening, after having set the mixture screw
>to the point that the idle speed is at its highest, just before it begins to
>drop.
>2) Carb with mixture and bypass screws, where the butterfly must be
>completelly closed and idle speed adjusted with the bypass screw, after the
>mixture screw is set correctly.
>
>Bill spiliotopoulos,
>'96 XJ, '06 TJ.
>
>>> Without having experience on your engine / carb /distributor, I can tell
>>> you what is usually the case.
>[quoted text clipped - 17 lines]
>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>> (More Off Road album links at bottom of the view page)
--
Message posted via CarKB.com
http://www.carkb.com/Uwe/Forums.aspx/jeep-cars/200707/1
+1
Bill Spiliotopoulos wrote:
>As I said I don't have any experience on Holley carburators or CJ5s.
>I have woked on Webers and Solexes, carbs with no separate throttle base,
>and with ported vacum for the advance.
>
>Anyway, if he has a manifold vacuum and not ported vacum signal for the
>advance, then the centrifugal advance mechanism plays a more significant
>role and will cause more noticeable problems (similar to the ones the OP
>has) if it doesn't work.
>In the case of manifold vacum signal the distrubutor is timed with less
>static advance (the advance measured @idle with vacum disconected), so that
>the advance is at acceptable limits when the engine idles were it has full
>vacum advance.
>When the engine revs above 2800-3000 rpm, it needs about 28 degrees of
>advance at full throttle, provided by the centrifugal advance mechanism. If
>this is not working, and because there is no vacum advance due to high load
>(weak manifold vacum), ending-up with a total advance close to zero degrees,
>as much as the static advance causing incomplete combustion, loss of power
>and backfiring.
>The simple test for the centrifugal advance mechanism is twisting the rotor
>and expect it to spring back, but a timing light with the vacuum advance
>disconected will show for sure if the centrifugal advance is working.
>
>About the idle speed setting using the butterfly, there are two cases:
>1) Carb with only a mixture adjusting screw, where you fine-tune the idle
>speed by adjusting the butterfly opening, after having set the mixture screw
>to the point that the idle speed is at its highest, just before it begins to
>drop.
>2) Carb with mixture and bypass screws, where the butterfly must be
>completelly closed and idle speed adjusted with the bypass screw, after the
>mixture screw is set correctly.
>
>Bill spiliotopoulos,
>'96 XJ, '06 TJ.
>
>>> Without having experience on your engine / carb /distributor, I can tell
>>> you what is usually the case.
>[quoted text clipped - 17 lines]
>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>> (More Off Road album links at bottom of the view page)
--
Message posted via CarKB.com
http://www.carkb.com/Uwe/Forums.aspx/jeep-cars/200707/1
07-19-2007, 12:42 AM
#164
Guest
Posts: n/a
Re: CJ5 misfires at high RPM/hard acceleration
here here Bill, Here here
+1
Bill Spiliotopoulos wrote:
>As I said I don't have any experience on Holley carburators or CJ5s.
>I have woked on Webers and Solexes, carbs with no separate throttle base,
>and with ported vacum for the advance.
>
>Anyway, if he has a manifold vacuum and not ported vacum signal for the
>advance, then the centrifugal advance mechanism plays a more significant
>role and will cause more noticeable problems (similar to the ones the OP
>has) if it doesn't work.
>In the case of manifold vacum signal the distrubutor is timed with less
>static advance (the advance measured @idle with vacum disconected), so that
>the advance is at acceptable limits when the engine idles were it has full
>vacum advance.
>When the engine revs above 2800-3000 rpm, it needs about 28 degrees of
>advance at full throttle, provided by the centrifugal advance mechanism. If
>this is not working, and because there is no vacum advance due to high load
>(weak manifold vacum), ending-up with a total advance close to zero degrees,
>as much as the static advance causing incomplete combustion, loss of power
>and backfiring.
>The simple test for the centrifugal advance mechanism is twisting the rotor
>and expect it to spring back, but a timing light with the vacuum advance
>disconected will show for sure if the centrifugal advance is working.
>
>About the idle speed setting using the butterfly, there are two cases:
>1) Carb with only a mixture adjusting screw, where you fine-tune the idle
>speed by adjusting the butterfly opening, after having set the mixture screw
>to the point that the idle speed is at its highest, just before it begins to
>drop.
>2) Carb with mixture and bypass screws, where the butterfly must be
>completelly closed and idle speed adjusted with the bypass screw, after the
>mixture screw is set correctly.
>
>Bill spiliotopoulos,
>'96 XJ, '06 TJ.
>
>>> Without having experience on your engine / carb /distributor, I can tell
>>> you what is usually the case.
>[quoted text clipped - 17 lines]
>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>> (More Off Road album links at bottom of the view page)
--
Message posted via CarKB.com
http://www.carkb.com/Uwe/Forums.aspx/jeep-cars/200707/1
+1
Bill Spiliotopoulos wrote:
>As I said I don't have any experience on Holley carburators or CJ5s.
>I have woked on Webers and Solexes, carbs with no separate throttle base,
>and with ported vacum for the advance.
>
>Anyway, if he has a manifold vacuum and not ported vacum signal for the
>advance, then the centrifugal advance mechanism plays a more significant
>role and will cause more noticeable problems (similar to the ones the OP
>has) if it doesn't work.
>In the case of manifold vacum signal the distrubutor is timed with less
>static advance (the advance measured @idle with vacum disconected), so that
>the advance is at acceptable limits when the engine idles were it has full
>vacum advance.
>When the engine revs above 2800-3000 rpm, it needs about 28 degrees of
>advance at full throttle, provided by the centrifugal advance mechanism. If
>this is not working, and because there is no vacum advance due to high load
>(weak manifold vacum), ending-up with a total advance close to zero degrees,
>as much as the static advance causing incomplete combustion, loss of power
>and backfiring.
>The simple test for the centrifugal advance mechanism is twisting the rotor
>and expect it to spring back, but a timing light with the vacuum advance
>disconected will show for sure if the centrifugal advance is working.
>
>About the idle speed setting using the butterfly, there are two cases:
>1) Carb with only a mixture adjusting screw, where you fine-tune the idle
>speed by adjusting the butterfly opening, after having set the mixture screw
>to the point that the idle speed is at its highest, just before it begins to
>drop.
>2) Carb with mixture and bypass screws, where the butterfly must be
>completelly closed and idle speed adjusted with the bypass screw, after the
>mixture screw is set correctly.
>
>Bill spiliotopoulos,
>'96 XJ, '06 TJ.
>
>>> Without having experience on your engine / carb /distributor, I can tell
>>> you what is usually the case.
>[quoted text clipped - 17 lines]
>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>> (More Off Road album links at bottom of the view page)
--
Message posted via CarKB.com
http://www.carkb.com/Uwe/Forums.aspx/jeep-cars/200707/1
07-19-2007, 12:42 AM
#165
Guest
Posts: n/a
Re: CJ5 misfires at high RPM/hard acceleration
here here Bill, Here here
+1
Bill Spiliotopoulos wrote:
>As I said I don't have any experience on Holley carburators or CJ5s.
>I have woked on Webers and Solexes, carbs with no separate throttle base,
>and with ported vacum for the advance.
>
>Anyway, if he has a manifold vacuum and not ported vacum signal for the
>advance, then the centrifugal advance mechanism plays a more significant
>role and will cause more noticeable problems (similar to the ones the OP
>has) if it doesn't work.
>In the case of manifold vacum signal the distrubutor is timed with less
>static advance (the advance measured @idle with vacum disconected), so that
>the advance is at acceptable limits when the engine idles were it has full
>vacum advance.
>When the engine revs above 2800-3000 rpm, it needs about 28 degrees of
>advance at full throttle, provided by the centrifugal advance mechanism. If
>this is not working, and because there is no vacum advance due to high load
>(weak manifold vacum), ending-up with a total advance close to zero degrees,
>as much as the static advance causing incomplete combustion, loss of power
>and backfiring.
>The simple test for the centrifugal advance mechanism is twisting the rotor
>and expect it to spring back, but a timing light with the vacuum advance
>disconected will show for sure if the centrifugal advance is working.
>
>About the idle speed setting using the butterfly, there are two cases:
>1) Carb with only a mixture adjusting screw, where you fine-tune the idle
>speed by adjusting the butterfly opening, after having set the mixture screw
>to the point that the idle speed is at its highest, just before it begins to
>drop.
>2) Carb with mixture and bypass screws, where the butterfly must be
>completelly closed and idle speed adjusted with the bypass screw, after the
>mixture screw is set correctly.
>
>Bill spiliotopoulos,
>'96 XJ, '06 TJ.
>
>>> Without having experience on your engine / carb /distributor, I can tell
>>> you what is usually the case.
>[quoted text clipped - 17 lines]
>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>> (More Off Road album links at bottom of the view page)
--
Message posted via CarKB.com
http://www.carkb.com/Uwe/Forums.aspx/jeep-cars/200707/1
+1
Bill Spiliotopoulos wrote:
>As I said I don't have any experience on Holley carburators or CJ5s.
>I have woked on Webers and Solexes, carbs with no separate throttle base,
>and with ported vacum for the advance.
>
>Anyway, if he has a manifold vacuum and not ported vacum signal for the
>advance, then the centrifugal advance mechanism plays a more significant
>role and will cause more noticeable problems (similar to the ones the OP
>has) if it doesn't work.
>In the case of manifold vacum signal the distrubutor is timed with less
>static advance (the advance measured @idle with vacum disconected), so that
>the advance is at acceptable limits when the engine idles were it has full
>vacum advance.
>When the engine revs above 2800-3000 rpm, it needs about 28 degrees of
>advance at full throttle, provided by the centrifugal advance mechanism. If
>this is not working, and because there is no vacum advance due to high load
>(weak manifold vacum), ending-up with a total advance close to zero degrees,
>as much as the static advance causing incomplete combustion, loss of power
>and backfiring.
>The simple test for the centrifugal advance mechanism is twisting the rotor
>and expect it to spring back, but a timing light with the vacuum advance
>disconected will show for sure if the centrifugal advance is working.
>
>About the idle speed setting using the butterfly, there are two cases:
>1) Carb with only a mixture adjusting screw, where you fine-tune the idle
>speed by adjusting the butterfly opening, after having set the mixture screw
>to the point that the idle speed is at its highest, just before it begins to
>drop.
>2) Carb with mixture and bypass screws, where the butterfly must be
>completelly closed and idle speed adjusted with the bypass screw, after the
>mixture screw is set correctly.
>
>Bill spiliotopoulos,
>'96 XJ, '06 TJ.
>
>>> Without having experience on your engine / carb /distributor, I can tell
>>> you what is usually the case.
>[quoted text clipped - 17 lines]
>> Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
>> (More Off Road album links at bottom of the view page)
--
Message posted via CarKB.com
http://www.carkb.com/Uwe/Forums.aspx/jeep-cars/200707/1
07-19-2007, 06:13 AM
#166
Guest
Posts: n/a
Re: CJ5 misfires at high RPM/hard acceleration
On Wed, 18 Jul 2007 09:56:22 -0700, "L.W. \(Bill\) ------ III"
<LWBill------@------.net> wrote:
> Emphasis on old.
> God Bless America, Bill O|||||||O
>mailto:-------------------- http://www.----------.com/
>
Well, duh, Bill...it's in my handle<g>
--
Old Crow "Yol Bolsun!"
'82 FLTC-P "Miss Pearl"
'95 YJ Rio Grande
BS#133, SENS, TOMKAT, MAMBM
--
Posted via a free Usenet account from http://www.teranews.com
<LWBill------@------.net> wrote:
> Emphasis on old.
> God Bless America, Bill O|||||||O
>mailto:-------------------- http://www.----------.com/
>
Well, duh, Bill...it's in my handle<g>
--
Old Crow "Yol Bolsun!"
'82 FLTC-P "Miss Pearl"
'95 YJ Rio Grande
BS#133, SENS, TOMKAT, MAMBM
--
Posted via a free Usenet account from http://www.teranews.com
07-19-2007, 06:13 AM
#167
Guest
Posts: n/a
Re: CJ5 misfires at high RPM/hard acceleration
On Wed, 18 Jul 2007 09:56:22 -0700, "L.W. \(Bill\) ------ III"
<LWBill------@------.net> wrote:
> Emphasis on old.
> God Bless America, Bill O|||||||O
>mailto:-------------------- http://www.----------.com/
>
Well, duh, Bill...it's in my handle<g>
--
Old Crow "Yol Bolsun!"
'82 FLTC-P "Miss Pearl"
'95 YJ Rio Grande
BS#133, SENS, TOMKAT, MAMBM
--
Posted via a free Usenet account from http://www.teranews.com
<LWBill------@------.net> wrote:
> Emphasis on old.
> God Bless America, Bill O|||||||O
>mailto:-------------------- http://www.----------.com/
>
Well, duh, Bill...it's in my handle<g>
--
Old Crow "Yol Bolsun!"
'82 FLTC-P "Miss Pearl"
'95 YJ Rio Grande
BS#133, SENS, TOMKAT, MAMBM
--
Posted via a free Usenet account from http://www.teranews.com
07-19-2007, 06:13 AM
#168
Guest
Posts: n/a
Re: CJ5 misfires at high RPM/hard acceleration
On Wed, 18 Jul 2007 09:56:22 -0700, "L.W. \(Bill\) ------ III"
<LWBill------@------.net> wrote:
> Emphasis on old.
> God Bless America, Bill O|||||||O
>mailto:-------------------- http://www.----------.com/
>
Well, duh, Bill...it's in my handle<g>
--
Old Crow "Yol Bolsun!"
'82 FLTC-P "Miss Pearl"
'95 YJ Rio Grande
BS#133, SENS, TOMKAT, MAMBM
--
Posted via a free Usenet account from http://www.teranews.com
<LWBill------@------.net> wrote:
> Emphasis on old.
> God Bless America, Bill O|||||||O
>mailto:-------------------- http://www.----------.com/
>
Well, duh, Bill...it's in my handle<g>
--
Old Crow "Yol Bolsun!"
'82 FLTC-P "Miss Pearl"
'95 YJ Rio Grande
BS#133, SENS, TOMKAT, MAMBM
--
Posted via a free Usenet account from http://www.teranews.com
07-19-2007, 06:13 AM
#169
Guest
Posts: n/a
Re: CJ5 misfires at high RPM/hard acceleration
On Wed, 18 Jul 2007 09:56:22 -0700, "L.W. \(Bill\) ------ III"
<LWBill------@------.net> wrote:
> Emphasis on old.
> God Bless America, Bill O|||||||O
>mailto:-------------------- http://www.----------.com/
>
Well, duh, Bill...it's in my handle<g>
--
Old Crow "Yol Bolsun!"
'82 FLTC-P "Miss Pearl"
'95 YJ Rio Grande
BS#133, SENS, TOMKAT, MAMBM
--
Posted via a free Usenet account from http://www.teranews.com
<LWBill------@------.net> wrote:
> Emphasis on old.
> God Bless America, Bill O|||||||O
>mailto:-------------------- http://www.----------.com/
>
Well, duh, Bill...it's in my handle<g>
--
Old Crow "Yol Bolsun!"
'82 FLTC-P "Miss Pearl"
'95 YJ Rio Grande
BS#133, SENS, TOMKAT, MAMBM
--
Posted via a free Usenet account from http://www.teranews.com
10-08-2013, 08:55 PM
#170
Junior Member
Join Date: Oct 2013
Location: Katy
Posts: 1
Re: CJ5 misfires at high RPM/hard acceleration
Gentlemen,
I'm having some problems tracking this down. When I accelerate hard
or get up to a certain RPM (about 3000) at cruising, I get popping
coming out of my exhaust & a huge lack in power. The engine has never
stalled, but I can't go any faster in that gear due to the misfiring.
I've done almost everything that I can think of short of checking the
timing chain & replacing the carburetor. Here's what I've done so
far:
Changed coil + ballast resistor + ignition wires/wire to distributor
Changed fuel filter + replaced all fuel lines
Changed fuel pump
Changed points + condenser
Changed plugs + plug wires (plugs gapped at .035)
Changed cap + rotor
Changed vacuum advance (this was confirmed bad & made a huge
difference)
The initial timing is 6 degrees BTDC & the dwell angle is about 31. I
get about 16hg of steady vacuum at idle & about 7psi of fuel pressure
at idle. The idle & even light acceleration is perfect, which makes
me think it's not a timing chain issue, but I don't know enough about
what the symptoms of a slipped chain would be to make that call. When
the engine is at TDC of piston 1's compression stroke, the rotor lines
up perfectly with cylinder 1's plug wire, which also makes me thing
it's not necessarily a timing chain issue. Since I have changed the
plugs & tried to further diagnose the problem, my plugs have turned
black. This along with the popping in the exhaust obviously mean my
mixture is either too rich, or something is going haywire with the
timing & causing the fuel to not burn at higher RPM. One thing worth
noting, is that I have not changed the plugs since they have been
fouled since I replaced the faulty vacuum advance. I didn't know if
this would make a difference or not & didn't want to risk fouling a
new set while troubleshooting. I can literally get flames to shoot
out of my exhaust if I abuse it enough. This happens on both sides &
I have dual exhaust, leading me to think it's not a valve issue,
unless I'm really unlucky & have a problem on both sides of the
engine.
The jeep is a recreational vehicle of sorts, used primarily to climb
up & down sand dunes. The symptoms all occured when my fuel pump died
about 2 years ago. After I replaced the pump, the engine started
doing this. I've since replaced it again to rule that out with no
change. I've also rebuilt the carburetor, but it was the first time I
ever did such a thing, so it's quite possible I missed something. The
accelerator pump works fine, the idle mixture screws are set very lean
(since I think the mixture is too rich for some reason), the power
valve has been replaced & I even checked it again last week & I can
see spray coming out of the booster venturi when I rev the engine (it
does this whether I'm moving or not). Another thing I noticed is that
when the engine is cold, if I hold my hand in front of the exhaust, it
sprays black fluid on me at idle. It's not a lot, but I noticed it
when it was sprayed on my leg one day. It has no smell to it other
than stinky exhaust, so I don't really know what this is. My coolant
level has not changed noticeably, so I wouldn't think it to be a water
leak, but I can't say with certainty.
Here are the basics:
1972 Jeep CJ5
AMC 304
Aftermarket parts:
Edlebrock peformer intake
Holley 600cfm 4-bbl carb
Edlebrock shorty headers
Thanks for any help you guys can give on this. I'm at a loss & don't
know what to do next.
-Matt
I'm having some problems tracking this down. When I accelerate hard
or get up to a certain RPM (about 3000) at cruising, I get popping
coming out of my exhaust & a huge lack in power. The engine has never
stalled, but I can't go any faster in that gear due to the misfiring.
I've done almost everything that I can think of short of checking the
timing chain & replacing the carburetor. Here's what I've done so
far:
Changed coil + ballast resistor + ignition wires/wire to distributor
Changed fuel filter + replaced all fuel lines
Changed fuel pump
Changed points + condenser
Changed plugs + plug wires (plugs gapped at .035)
Changed cap + rotor
Changed vacuum advance (this was confirmed bad & made a huge
difference)
The initial timing is 6 degrees BTDC & the dwell angle is about 31. I
get about 16hg of steady vacuum at idle & about 7psi of fuel pressure
at idle. The idle & even light acceleration is perfect, which makes
me think it's not a timing chain issue, but I don't know enough about
what the symptoms of a slipped chain would be to make that call. When
the engine is at TDC of piston 1's compression stroke, the rotor lines
up perfectly with cylinder 1's plug wire, which also makes me thing
it's not necessarily a timing chain issue. Since I have changed the
plugs & tried to further diagnose the problem, my plugs have turned
black. This along with the popping in the exhaust obviously mean my
mixture is either too rich, or something is going haywire with the
timing & causing the fuel to not burn at higher RPM. One thing worth
noting, is that I have not changed the plugs since they have been
fouled since I replaced the faulty vacuum advance. I didn't know if
this would make a difference or not & didn't want to risk fouling a
new set while troubleshooting. I can literally get flames to shoot
out of my exhaust if I abuse it enough. This happens on both sides &
I have dual exhaust, leading me to think it's not a valve issue,
unless I'm really unlucky & have a problem on both sides of the
engine.
The jeep is a recreational vehicle of sorts, used primarily to climb
up & down sand dunes. The symptoms all occured when my fuel pump died
about 2 years ago. After I replaced the pump, the engine started
doing this. I've since replaced it again to rule that out with no
change. I've also rebuilt the carburetor, but it was the first time I
ever did such a thing, so it's quite possible I missed something. The
accelerator pump works fine, the idle mixture screws are set very lean
(since I think the mixture is too rich for some reason), the power
valve has been replaced & I even checked it again last week & I can
see spray coming out of the booster venturi when I rev the engine (it
does this whether I'm moving or not). Another thing I noticed is that
when the engine is cold, if I hold my hand in front of the exhaust, it
sprays black fluid on me at idle. It's not a lot, but I noticed it
when it was sprayed on my leg one day. It has no smell to it other
than stinky exhaust, so I don't really know what this is. My coolant
level has not changed noticeably, so I wouldn't think it to be a water
leak, but I can't say with certainty.
Here are the basics:
1972 Jeep CJ5
AMC 304
Aftermarket parts:
Edlebrock peformer intake
Holley 600cfm 4-bbl carb
Edlebrock shorty headers
Thanks for any help you guys can give on this. I'm at a loss & don't
know what to do next.
-Matt
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juanjlopez@gmail.com
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04-05-2007 08:24 PM
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