4.0 L spark knock
11-09-2004, 08:08 PM
#14
Guest
Posts: n/a
Re: 4.0 L spark knock
I have an '03 with an I6 and I get it too (though it's not at all
severe). Not all the time, so I just write it off to "bad" gas....
It started at about 20K miles and I now have 55K miles. I get my gas
at the same place usually, so I'm not sure if it is vendor specific.
Do you run the hi-octane because of the supercharger? If not, why?
Higher octane gas is less volitile than regular- it takes more heat to
"explode"- and I've been advised NOT to run it in the Jeep.
dalewhite@aol.com (Dalewhite) wrote in message news:<20041109110628.11961.00000273@mb-m16.aol.com>...
> I have a 00 TJ - 4.0. I am getting what I call spark knock at lower RPMs under
> light acceleration. This is a fairly recent development and I have gotten
> little help in identifying the cause of the problem. The engine is stock
> except for the following: Avenger Supercharger with associated larger than
> stock injectors. A 700R4 AT which has the crank position sensor relocated to
> the front crankshaft pulley. I burn hi-octane fuel exclusively. I cannot see
> how the supercharger install would produce this effect, as the engine is not
> showing boost when the knocking appears. In my old car days I would suspect
> the timing to be at fault but this computer ignition system is way beyond me.
> Does anyone have experience with this or suggestion where I might direct my
> search?
> tia dw
severe). Not all the time, so I just write it off to "bad" gas....
It started at about 20K miles and I now have 55K miles. I get my gas
at the same place usually, so I'm not sure if it is vendor specific.
Do you run the hi-octane because of the supercharger? If not, why?
Higher octane gas is less volitile than regular- it takes more heat to
"explode"- and I've been advised NOT to run it in the Jeep.
dalewhite@aol.com (Dalewhite) wrote in message news:<20041109110628.11961.00000273@mb-m16.aol.com>...
> I have a 00 TJ - 4.0. I am getting what I call spark knock at lower RPMs under
> light acceleration. This is a fairly recent development and I have gotten
> little help in identifying the cause of the problem. The engine is stock
> except for the following: Avenger Supercharger with associated larger than
> stock injectors. A 700R4 AT which has the crank position sensor relocated to
> the front crankshaft pulley. I burn hi-octane fuel exclusively. I cannot see
> how the supercharger install would produce this effect, as the engine is not
> showing boost when the knocking appears. In my old car days I would suspect
> the timing to be at fault but this computer ignition system is way beyond me.
> Does anyone have experience with this or suggestion where I might direct my
> search?
> tia dw
11-09-2004, 08:08 PM
#15
Guest
Posts: n/a
Re: 4.0 L spark knock
I have an '03 with an I6 and I get it too (though it's not at all
severe). Not all the time, so I just write it off to "bad" gas....
It started at about 20K miles and I now have 55K miles. I get my gas
at the same place usually, so I'm not sure if it is vendor specific.
Do you run the hi-octane because of the supercharger? If not, why?
Higher octane gas is less volitile than regular- it takes more heat to
"explode"- and I've been advised NOT to run it in the Jeep.
dalewhite@aol.com (Dalewhite) wrote in message news:<20041109110628.11961.00000273@mb-m16.aol.com>...
> I have a 00 TJ - 4.0. I am getting what I call spark knock at lower RPMs under
> light acceleration. This is a fairly recent development and I have gotten
> little help in identifying the cause of the problem. The engine is stock
> except for the following: Avenger Supercharger with associated larger than
> stock injectors. A 700R4 AT which has the crank position sensor relocated to
> the front crankshaft pulley. I burn hi-octane fuel exclusively. I cannot see
> how the supercharger install would produce this effect, as the engine is not
> showing boost when the knocking appears. In my old car days I would suspect
> the timing to be at fault but this computer ignition system is way beyond me.
> Does anyone have experience with this or suggestion where I might direct my
> search?
> tia dw
severe). Not all the time, so I just write it off to "bad" gas....
It started at about 20K miles and I now have 55K miles. I get my gas
at the same place usually, so I'm not sure if it is vendor specific.
Do you run the hi-octane because of the supercharger? If not, why?
Higher octane gas is less volitile than regular- it takes more heat to
"explode"- and I've been advised NOT to run it in the Jeep.
dalewhite@aol.com (Dalewhite) wrote in message news:<20041109110628.11961.00000273@mb-m16.aol.com>...
> I have a 00 TJ - 4.0. I am getting what I call spark knock at lower RPMs under
> light acceleration. This is a fairly recent development and I have gotten
> little help in identifying the cause of the problem. The engine is stock
> except for the following: Avenger Supercharger with associated larger than
> stock injectors. A 700R4 AT which has the crank position sensor relocated to
> the front crankshaft pulley. I burn hi-octane fuel exclusively. I cannot see
> how the supercharger install would produce this effect, as the engine is not
> showing boost when the knocking appears. In my old car days I would suspect
> the timing to be at fault but this computer ignition system is way beyond me.
> Does anyone have experience with this or suggestion where I might direct my
> search?
> tia dw
11-09-2004, 08:08 PM
#16
Guest
Posts: n/a
Re: 4.0 L spark knock
I have an '03 with an I6 and I get it too (though it's not at all
severe). Not all the time, so I just write it off to "bad" gas....
It started at about 20K miles and I now have 55K miles. I get my gas
at the same place usually, so I'm not sure if it is vendor specific.
Do you run the hi-octane because of the supercharger? If not, why?
Higher octane gas is less volitile than regular- it takes more heat to
"explode"- and I've been advised NOT to run it in the Jeep.
dalewhite@aol.com (Dalewhite) wrote in message news:<20041109110628.11961.00000273@mb-m16.aol.com>...
> I have a 00 TJ - 4.0. I am getting what I call spark knock at lower RPMs under
> light acceleration. This is a fairly recent development and I have gotten
> little help in identifying the cause of the problem. The engine is stock
> except for the following: Avenger Supercharger with associated larger than
> stock injectors. A 700R4 AT which has the crank position sensor relocated to
> the front crankshaft pulley. I burn hi-octane fuel exclusively. I cannot see
> how the supercharger install would produce this effect, as the engine is not
> showing boost when the knocking appears. In my old car days I would suspect
> the timing to be at fault but this computer ignition system is way beyond me.
> Does anyone have experience with this or suggestion where I might direct my
> search?
> tia dw
severe). Not all the time, so I just write it off to "bad" gas....
It started at about 20K miles and I now have 55K miles. I get my gas
at the same place usually, so I'm not sure if it is vendor specific.
Do you run the hi-octane because of the supercharger? If not, why?
Higher octane gas is less volitile than regular- it takes more heat to
"explode"- and I've been advised NOT to run it in the Jeep.
dalewhite@aol.com (Dalewhite) wrote in message news:<20041109110628.11961.00000273@mb-m16.aol.com>...
> I have a 00 TJ - 4.0. I am getting what I call spark knock at lower RPMs under
> light acceleration. This is a fairly recent development and I have gotten
> little help in identifying the cause of the problem. The engine is stock
> except for the following: Avenger Supercharger with associated larger than
> stock injectors. A 700R4 AT which has the crank position sensor relocated to
> the front crankshaft pulley. I burn hi-octane fuel exclusively. I cannot see
> how the supercharger install would produce this effect, as the engine is not
> showing boost when the knocking appears. In my old car days I would suspect
> the timing to be at fault but this computer ignition system is way beyond me.
> Does anyone have experience with this or suggestion where I might direct my
> search?
> tia dw
11-09-2004, 09:26 PM
#17
Guest
Posts: n/a
Re: 4.0 L spark knock
Dalewhite did pass the time by typing:
> I have a 00 TJ - 4.0. I am getting what I call spark knock at lower RPMs
> under light acceleration. This is a fairly recent development and I have
> gotten little help in identifying the cause of the problem. The engine is
> stock except for the following: Avenger Supercharger with associated larger
> than stock injectors. A 700R4 AT which has the crank position sensor
> relocated to the front crankshaft pulley. I burn hi-octane fuel exclusively.
> I cannot see how the supercharger install would produce this effect, as the
> engine is not showing boost when the knocking appears. In my old car days I
> would suspect the timing to be at fault but this computer ignition system is
> way beyond me. Does anyone have experience with this or suggestion where I
> might direct my search?
For me it's usually bad gas and a bottle of the NOS brand gas drier does wonders.
There are others out there, just make sure they are safe for the O2 sensor.
A local 7-11 gave the ZJ a real classic "blown head gasket" white cloud one time.
Did they give you a heat range cooler spark plug? You should probably be running
at least one heat range cooler. For the I6 that's an RC9YC4 or Autolite 3924.
Hot plugs can be a source of preignition problems.
There are various sensors that can also do this but you would have lots more
problems than just a little spark knock and I don't believe your 00 has an external
fuel filter to mess with, think yours is in the tank.
Good luck. Hope you find the problem.
--
-- DougW -- 93 ZJ 4.0 http://members.***.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
Banks Header - and BEER, in the fridge!
> I have a 00 TJ - 4.0. I am getting what I call spark knock at lower RPMs
> under light acceleration. This is a fairly recent development and I have
> gotten little help in identifying the cause of the problem. The engine is
> stock except for the following: Avenger Supercharger with associated larger
> than stock injectors. A 700R4 AT which has the crank position sensor
> relocated to the front crankshaft pulley. I burn hi-octane fuel exclusively.
> I cannot see how the supercharger install would produce this effect, as the
> engine is not showing boost when the knocking appears. In my old car days I
> would suspect the timing to be at fault but this computer ignition system is
> way beyond me. Does anyone have experience with this or suggestion where I
> might direct my search?
For me it's usually bad gas and a bottle of the NOS brand gas drier does wonders.
There are others out there, just make sure they are safe for the O2 sensor.
A local 7-11 gave the ZJ a real classic "blown head gasket" white cloud one time.
Did they give you a heat range cooler spark plug? You should probably be running
at least one heat range cooler. For the I6 that's an RC9YC4 or Autolite 3924.
Hot plugs can be a source of preignition problems.
There are various sensors that can also do this but you would have lots more
problems than just a little spark knock and I don't believe your 00 has an external
fuel filter to mess with, think yours is in the tank.
Good luck. Hope you find the problem.
--
-- DougW -- 93 ZJ 4.0 http://members.***.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
Banks Header - and BEER, in the fridge!
11-09-2004, 09:26 PM
#18
Guest
Posts: n/a
Re: 4.0 L spark knock
Dalewhite did pass the time by typing:
> I have a 00 TJ - 4.0. I am getting what I call spark knock at lower RPMs
> under light acceleration. This is a fairly recent development and I have
> gotten little help in identifying the cause of the problem. The engine is
> stock except for the following: Avenger Supercharger with associated larger
> than stock injectors. A 700R4 AT which has the crank position sensor
> relocated to the front crankshaft pulley. I burn hi-octane fuel exclusively.
> I cannot see how the supercharger install would produce this effect, as the
> engine is not showing boost when the knocking appears. In my old car days I
> would suspect the timing to be at fault but this computer ignition system is
> way beyond me. Does anyone have experience with this or suggestion where I
> might direct my search?
For me it's usually bad gas and a bottle of the NOS brand gas drier does wonders.
There are others out there, just make sure they are safe for the O2 sensor.
A local 7-11 gave the ZJ a real classic "blown head gasket" white cloud one time.
Did they give you a heat range cooler spark plug? You should probably be running
at least one heat range cooler. For the I6 that's an RC9YC4 or Autolite 3924.
Hot plugs can be a source of preignition problems.
There are various sensors that can also do this but you would have lots more
problems than just a little spark knock and I don't believe your 00 has an external
fuel filter to mess with, think yours is in the tank.
Good luck. Hope you find the problem.
--
-- DougW -- 93 ZJ 4.0 http://members.***.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
Banks Header - and BEER, in the fridge!
> I have a 00 TJ - 4.0. I am getting what I call spark knock at lower RPMs
> under light acceleration. This is a fairly recent development and I have
> gotten little help in identifying the cause of the problem. The engine is
> stock except for the following: Avenger Supercharger with associated larger
> than stock injectors. A 700R4 AT which has the crank position sensor
> relocated to the front crankshaft pulley. I burn hi-octane fuel exclusively.
> I cannot see how the supercharger install would produce this effect, as the
> engine is not showing boost when the knocking appears. In my old car days I
> would suspect the timing to be at fault but this computer ignition system is
> way beyond me. Does anyone have experience with this or suggestion where I
> might direct my search?
For me it's usually bad gas and a bottle of the NOS brand gas drier does wonders.
There are others out there, just make sure they are safe for the O2 sensor.
A local 7-11 gave the ZJ a real classic "blown head gasket" white cloud one time.
Did they give you a heat range cooler spark plug? You should probably be running
at least one heat range cooler. For the I6 that's an RC9YC4 or Autolite 3924.
Hot plugs can be a source of preignition problems.
There are various sensors that can also do this but you would have lots more
problems than just a little spark knock and I don't believe your 00 has an external
fuel filter to mess with, think yours is in the tank.
Good luck. Hope you find the problem.
--
-- DougW -- 93 ZJ 4.0 http://members.***.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
Banks Header - and BEER, in the fridge!
11-09-2004, 09:26 PM
#19
Guest
Posts: n/a
Re: 4.0 L spark knock
Dalewhite did pass the time by typing:
> I have a 00 TJ - 4.0. I am getting what I call spark knock at lower RPMs
> under light acceleration. This is a fairly recent development and I have
> gotten little help in identifying the cause of the problem. The engine is
> stock except for the following: Avenger Supercharger with associated larger
> than stock injectors. A 700R4 AT which has the crank position sensor
> relocated to the front crankshaft pulley. I burn hi-octane fuel exclusively.
> I cannot see how the supercharger install would produce this effect, as the
> engine is not showing boost when the knocking appears. In my old car days I
> would suspect the timing to be at fault but this computer ignition system is
> way beyond me. Does anyone have experience with this or suggestion where I
> might direct my search?
For me it's usually bad gas and a bottle of the NOS brand gas drier does wonders.
There are others out there, just make sure they are safe for the O2 sensor.
A local 7-11 gave the ZJ a real classic "blown head gasket" white cloud one time.
Did they give you a heat range cooler spark plug? You should probably be running
at least one heat range cooler. For the I6 that's an RC9YC4 or Autolite 3924.
Hot plugs can be a source of preignition problems.
There are various sensors that can also do this but you would have lots more
problems than just a little spark knock and I don't believe your 00 has an external
fuel filter to mess with, think yours is in the tank.
Good luck. Hope you find the problem.
--
-- DougW -- 93 ZJ 4.0 http://members.***.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
Banks Header - and BEER, in the fridge!
> I have a 00 TJ - 4.0. I am getting what I call spark knock at lower RPMs
> under light acceleration. This is a fairly recent development and I have
> gotten little help in identifying the cause of the problem. The engine is
> stock except for the following: Avenger Supercharger with associated larger
> than stock injectors. A 700R4 AT which has the crank position sensor
> relocated to the front crankshaft pulley. I burn hi-octane fuel exclusively.
> I cannot see how the supercharger install would produce this effect, as the
> engine is not showing boost when the knocking appears. In my old car days I
> would suspect the timing to be at fault but this computer ignition system is
> way beyond me. Does anyone have experience with this or suggestion where I
> might direct my search?
For me it's usually bad gas and a bottle of the NOS brand gas drier does wonders.
There are others out there, just make sure they are safe for the O2 sensor.
A local 7-11 gave the ZJ a real classic "blown head gasket" white cloud one time.
Did they give you a heat range cooler spark plug? You should probably be running
at least one heat range cooler. For the I6 that's an RC9YC4 or Autolite 3924.
Hot plugs can be a source of preignition problems.
There are various sensors that can also do this but you would have lots more
problems than just a little spark knock and I don't believe your 00 has an external
fuel filter to mess with, think yours is in the tank.
Good luck. Hope you find the problem.
--
-- DougW -- 93 ZJ 4.0 http://members.***.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
Banks Header - and BEER, in the fridge!
11-10-2004, 06:51 AM
#20
Guest
Posts: n/a
Re: 4.0 L spark knock
Isn't a butterfly valve part of a carburator? Don't know engines well
enough to know for sure....
"L.W. ("ßill") ------ III" <----------@***.net> wrote in message
news:41911FC3.2517BBB@***.net...
> Hi Dale,
> Just after you crack the the butterfly you're going to be under
> eight pounds, if you can't find a gas station with high enough octane
> then you're going to have to retard the spark. Even the stock computer
> is programmable, but it takes DRB-III scanner:
> http://search.ebay.com/DRB-III_W0QQs...ectZ1QQfromZR8 Maybe
> the shop that sold you blower will pull it back for free.
> God Bless America, ßill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> Dalewhite wrote:
>>
>> I have a 00 TJ - 4.0. I am getting what I call spark knock at lower RPMs
>> under
>> light acceleration. This is a fairly recent development and I have
>> gotten
>> little help in identifying the cause of the problem. The engine is
>> stock
>> except for the following: Avenger Supercharger with associated larger
>> than
>> stock injectors. A 700R4 AT which has the crank position sensor relocated
>> to
>> the front crankshaft pulley. I burn hi-octane fuel exclusively. I
>> cannot see
>> how the supercharger install would produce this effect, as the engine is
>> not
>> showing boost when the knocking appears. In my old car days I would
>> suspect
>> the timing to be at fault but this computer ignition system is way beyond
>> me.
>> Does anyone have experience with this or suggestion where I might direct
>> my
>> search?
>> tia dw
enough to know for sure....
"L.W. ("ßill") ------ III" <----------@***.net> wrote in message
news:41911FC3.2517BBB@***.net...
> Hi Dale,
> Just after you crack the the butterfly you're going to be under
> eight pounds, if you can't find a gas station with high enough octane
> then you're going to have to retard the spark. Even the stock computer
> is programmable, but it takes DRB-III scanner:
> http://search.ebay.com/DRB-III_W0QQs...ectZ1QQfromZR8 Maybe
> the shop that sold you blower will pull it back for free.
> God Bless America, ßill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> Dalewhite wrote:
>>
>> I have a 00 TJ - 4.0. I am getting what I call spark knock at lower RPMs
>> under
>> light acceleration. This is a fairly recent development and I have
>> gotten
>> little help in identifying the cause of the problem. The engine is
>> stock
>> except for the following: Avenger Supercharger with associated larger
>> than
>> stock injectors. A 700R4 AT which has the crank position sensor relocated
>> to
>> the front crankshaft pulley. I burn hi-octane fuel exclusively. I
>> cannot see
>> how the supercharger install would produce this effect, as the engine is
>> not
>> showing boost when the knocking appears. In my old car days I would
>> suspect
>> the timing to be at fault but this computer ignition system is way beyond
>> me.
>> Does anyone have experience with this or suggestion where I might direct
>> my
>> search?
>> tia dw