Engine backfire
#31
Guest
Posts: n/a
Re: Engine backfire
Just wondering - wouldn't the old test of hanging a shop cloth over
the end of the tailpipe pretty well identify a possible valve problem?
Hold it so it hangs straight over the end of the pipe. It will blow
out, maybe falling back to touch the pipe, unless you have an actual
exhaust valve problem which will try and suck it up the pipe when that
cylinder is in the right position. That will cause a backfire, BTW,
and it can be pretty hard to spot if it's a weak valve spring.
On Thu, 19 Feb 2004 02:36:46 UTC L.W.(ßill) ------ III
<----------@***.net> wrote:
> Make yourself a stethoscope and see if you can find it cold.
> Leaving it leak will foul your oxygen sensor, making your electronic
> injection richer, which in turn fouls your spark plugs and washes down
> your cylinder walls of lubricant, hastening wear.
> God Bless America, ßill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> "ezeppelin@msn.com" wrote:
> >
> > Yick. Tracing out smog and exhaust leaks are way beyond my skill set.
> > (in other words, sounds like I'm in for a pricey repair.)
> >
> > What is the downside to leaving it unrepaired? (Emissions are not a
> > concern as I have antqiue tags and am therefore inspection exempt.)
> >
> > Also... it is virtually always sounds like it is the right exhaust
> > pipe, not the left. Does this indicate that my air leak is probably
> > in that half of the system?
--
Will Honea <whonea@codenet.net>
the end of the tailpipe pretty well identify a possible valve problem?
Hold it so it hangs straight over the end of the pipe. It will blow
out, maybe falling back to touch the pipe, unless you have an actual
exhaust valve problem which will try and suck it up the pipe when that
cylinder is in the right position. That will cause a backfire, BTW,
and it can be pretty hard to spot if it's a weak valve spring.
On Thu, 19 Feb 2004 02:36:46 UTC L.W.(ßill) ------ III
<----------@***.net> wrote:
> Make yourself a stethoscope and see if you can find it cold.
> Leaving it leak will foul your oxygen sensor, making your electronic
> injection richer, which in turn fouls your spark plugs and washes down
> your cylinder walls of lubricant, hastening wear.
> God Bless America, ßill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> "ezeppelin@msn.com" wrote:
> >
> > Yick. Tracing out smog and exhaust leaks are way beyond my skill set.
> > (in other words, sounds like I'm in for a pricey repair.)
> >
> > What is the downside to leaving it unrepaired? (Emissions are not a
> > concern as I have antqiue tags and am therefore inspection exempt.)
> >
> > Also... it is virtually always sounds like it is the right exhaust
> > pipe, not the left. Does this indicate that my air leak is probably
> > in that half of the system?
--
Will Honea <whonea@codenet.net>
#32
Guest
Posts: n/a
Re: Engine backfire
> Make yourself a stethoscope and see if you can find it cold.
Not sure I follow. If by "cold" you mean with the engine not
running... there wouldn't be any sound anywhere in the system... so
I'm not sure how I would find the leak with a stethoscope?
Not sure I follow. If by "cold" you mean with the engine not
running... there wouldn't be any sound anywhere in the system... so
I'm not sure how I would find the leak with a stethoscope?
#33
Guest
Posts: n/a
Re: Engine backfire
> Make yourself a stethoscope and see if you can find it cold.
Not sure I follow. If by "cold" you mean with the engine not
running... there wouldn't be any sound anywhere in the system... so
I'm not sure how I would find the leak with a stethoscope?
Not sure I follow. If by "cold" you mean with the engine not
running... there wouldn't be any sound anywhere in the system... so
I'm not sure how I would find the leak with a stethoscope?
#34
Guest
Posts: n/a
Re: Engine backfire
> Make yourself a stethoscope and see if you can find it cold.
Not sure I follow. If by "cold" you mean with the engine not
running... there wouldn't be any sound anywhere in the system... so
I'm not sure how I would find the leak with a stethoscope?
Not sure I follow. If by "cold" you mean with the engine not
running... there wouldn't be any sound anywhere in the system... so
I'm not sure how I would find the leak with a stethoscope?
#35
Guest
Posts: n/a
Re: Engine backfire
> OP said "injected chevy" I think you could bet the farm that it's a
> stock 350".
Correct.... and it is a CJ7 jeep, but virtually none of the
mechanical or electronic components are the original AMC manufacture,
so don't read too much into that. Basically a CJ7 body with all kinds
of Ford, Chevy, Dodge, and aftermarket parts underneath! (no honda
parts as of yet... ;-)
> stock 350".
Correct.... and it is a CJ7 jeep, but virtually none of the
mechanical or electronic components are the original AMC manufacture,
so don't read too much into that. Basically a CJ7 body with all kinds
of Ford, Chevy, Dodge, and aftermarket parts underneath! (no honda
parts as of yet... ;-)
#36
Guest
Posts: n/a
Re: Engine backfire
> OP said "injected chevy" I think you could bet the farm that it's a
> stock 350".
Correct.... and it is a CJ7 jeep, but virtually none of the
mechanical or electronic components are the original AMC manufacture,
so don't read too much into that. Basically a CJ7 body with all kinds
of Ford, Chevy, Dodge, and aftermarket parts underneath! (no honda
parts as of yet... ;-)
> stock 350".
Correct.... and it is a CJ7 jeep, but virtually none of the
mechanical or electronic components are the original AMC manufacture,
so don't read too much into that. Basically a CJ7 body with all kinds
of Ford, Chevy, Dodge, and aftermarket parts underneath! (no honda
parts as of yet... ;-)
#37
Guest
Posts: n/a
Re: Engine backfire
> OP said "injected chevy" I think you could bet the farm that it's a
> stock 350".
Correct.... and it is a CJ7 jeep, but virtually none of the
mechanical or electronic components are the original AMC manufacture,
so don't read too much into that. Basically a CJ7 body with all kinds
of Ford, Chevy, Dodge, and aftermarket parts underneath! (no honda
parts as of yet... ;-)
> stock 350".
Correct.... and it is a CJ7 jeep, but virtually none of the
mechanical or electronic components are the original AMC manufacture,
so don't read too much into that. Basically a CJ7 body with all kinds
of Ford, Chevy, Dodge, and aftermarket parts underneath! (no honda
parts as of yet... ;-)
#38
Guest
Posts: n/a
Re: Engine backfire
"ezeppelin@msn.com" wrote:
>
> > OP said "injected chevy" I think you could bet the farm that it's a
> > stock 350".
>
> Correct.... and it is a CJ7 jeep, but virtually none of the
> mechanical or electronic components are the original AMC manufacture,
> so don't read too much into that. Basically a CJ7 body with all kinds
> of Ford, Chevy, Dodge, and aftermarket parts underneath! (no honda
> parts as of yet... ;-)
So I take it it is a 'built' 350 or is it a direct transplant?
Ok, anyway I have two thoughts....
One is it has been built and the intake manifold needs to be retorqued
down because it is leaking allowing a lean backfire.
This can be found by using a can of carb cleaner spray. At idle spray
along the gasket seam especially at the 4 corners. If you have a leak,
the idle will burp. A cracked big vacuum line like the PCV or brake
booster line can cause it too, so spray the vacuum connections as well.
Second is the exhaust manifolds need to be retorqued down. If they were
messed with and not just transplanted, then they likely need a second
torque like the intake. These tend to just plain come loose.
Then a third is maybe the bolts at the exhaust flange has worked loose.
The exhaust leaks can be located by using a piece of tubing or even a
chunk of garden hose held to the ear. If there is a leak you can hear
it through a piece of tube held close to it.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
>
> > OP said "injected chevy" I think you could bet the farm that it's a
> > stock 350".
>
> Correct.... and it is a CJ7 jeep, but virtually none of the
> mechanical or electronic components are the original AMC manufacture,
> so don't read too much into that. Basically a CJ7 body with all kinds
> of Ford, Chevy, Dodge, and aftermarket parts underneath! (no honda
> parts as of yet... ;-)
So I take it it is a 'built' 350 or is it a direct transplant?
Ok, anyway I have two thoughts....
One is it has been built and the intake manifold needs to be retorqued
down because it is leaking allowing a lean backfire.
This can be found by using a can of carb cleaner spray. At idle spray
along the gasket seam especially at the 4 corners. If you have a leak,
the idle will burp. A cracked big vacuum line like the PCV or brake
booster line can cause it too, so spray the vacuum connections as well.
Second is the exhaust manifolds need to be retorqued down. If they were
messed with and not just transplanted, then they likely need a second
torque like the intake. These tend to just plain come loose.
Then a third is maybe the bolts at the exhaust flange has worked loose.
The exhaust leaks can be located by using a piece of tubing or even a
chunk of garden hose held to the ear. If there is a leak you can hear
it through a piece of tube held close to it.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
#39
Guest
Posts: n/a
Re: Engine backfire
"ezeppelin@msn.com" wrote:
>
> > OP said "injected chevy" I think you could bet the farm that it's a
> > stock 350".
>
> Correct.... and it is a CJ7 jeep, but virtually none of the
> mechanical or electronic components are the original AMC manufacture,
> so don't read too much into that. Basically a CJ7 body with all kinds
> of Ford, Chevy, Dodge, and aftermarket parts underneath! (no honda
> parts as of yet... ;-)
So I take it it is a 'built' 350 or is it a direct transplant?
Ok, anyway I have two thoughts....
One is it has been built and the intake manifold needs to be retorqued
down because it is leaking allowing a lean backfire.
This can be found by using a can of carb cleaner spray. At idle spray
along the gasket seam especially at the 4 corners. If you have a leak,
the idle will burp. A cracked big vacuum line like the PCV or brake
booster line can cause it too, so spray the vacuum connections as well.
Second is the exhaust manifolds need to be retorqued down. If they were
messed with and not just transplanted, then they likely need a second
torque like the intake. These tend to just plain come loose.
Then a third is maybe the bolts at the exhaust flange has worked loose.
The exhaust leaks can be located by using a piece of tubing or even a
chunk of garden hose held to the ear. If there is a leak you can hear
it through a piece of tube held close to it.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
>
> > OP said "injected chevy" I think you could bet the farm that it's a
> > stock 350".
>
> Correct.... and it is a CJ7 jeep, but virtually none of the
> mechanical or electronic components are the original AMC manufacture,
> so don't read too much into that. Basically a CJ7 body with all kinds
> of Ford, Chevy, Dodge, and aftermarket parts underneath! (no honda
> parts as of yet... ;-)
So I take it it is a 'built' 350 or is it a direct transplant?
Ok, anyway I have two thoughts....
One is it has been built and the intake manifold needs to be retorqued
down because it is leaking allowing a lean backfire.
This can be found by using a can of carb cleaner spray. At idle spray
along the gasket seam especially at the 4 corners. If you have a leak,
the idle will burp. A cracked big vacuum line like the PCV or brake
booster line can cause it too, so spray the vacuum connections as well.
Second is the exhaust manifolds need to be retorqued down. If they were
messed with and not just transplanted, then they likely need a second
torque like the intake. These tend to just plain come loose.
Then a third is maybe the bolts at the exhaust flange has worked loose.
The exhaust leaks can be located by using a piece of tubing or even a
chunk of garden hose held to the ear. If there is a leak you can hear
it through a piece of tube held close to it.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
#40
Guest
Posts: n/a
Re: Engine backfire
"ezeppelin@msn.com" wrote:
>
> > OP said "injected chevy" I think you could bet the farm that it's a
> > stock 350".
>
> Correct.... and it is a CJ7 jeep, but virtually none of the
> mechanical or electronic components are the original AMC manufacture,
> so don't read too much into that. Basically a CJ7 body with all kinds
> of Ford, Chevy, Dodge, and aftermarket parts underneath! (no honda
> parts as of yet... ;-)
So I take it it is a 'built' 350 or is it a direct transplant?
Ok, anyway I have two thoughts....
One is it has been built and the intake manifold needs to be retorqued
down because it is leaking allowing a lean backfire.
This can be found by using a can of carb cleaner spray. At idle spray
along the gasket seam especially at the 4 corners. If you have a leak,
the idle will burp. A cracked big vacuum line like the PCV or brake
booster line can cause it too, so spray the vacuum connections as well.
Second is the exhaust manifolds need to be retorqued down. If they were
messed with and not just transplanted, then they likely need a second
torque like the intake. These tend to just plain come loose.
Then a third is maybe the bolts at the exhaust flange has worked loose.
The exhaust leaks can be located by using a piece of tubing or even a
chunk of garden hose held to the ear. If there is a leak you can hear
it through a piece of tube held close to it.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
>
> > OP said "injected chevy" I think you could bet the farm that it's a
> > stock 350".
>
> Correct.... and it is a CJ7 jeep, but virtually none of the
> mechanical or electronic components are the original AMC manufacture,
> so don't read too much into that. Basically a CJ7 body with all kinds
> of Ford, Chevy, Dodge, and aftermarket parts underneath! (no honda
> parts as of yet... ;-)
So I take it it is a 'built' 350 or is it a direct transplant?
Ok, anyway I have two thoughts....
One is it has been built and the intake manifold needs to be retorqued
down because it is leaking allowing a lean backfire.
This can be found by using a can of carb cleaner spray. At idle spray
along the gasket seam especially at the 4 corners. If you have a leak,
the idle will burp. A cracked big vacuum line like the PCV or brake
booster line can cause it too, so spray the vacuum connections as well.
Second is the exhaust manifolds need to be retorqued down. If they were
messed with and not just transplanted, then they likely need a second
torque like the intake. These tend to just plain come loose.
Then a third is maybe the bolts at the exhaust flange has worked loose.
The exhaust leaks can be located by using a piece of tubing or even a
chunk of garden hose held to the ear. If there is a leak you can hear
it through a piece of tube held close to it.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's