Your probably right in your own way but the difference between my 4.0 and
the 4.0 in the owners manual is that mine is a highly modified 4.0! So I
feed it no less than 93 octane!
Your 93 oxy is the same garbage as 87 oxy. The only real premium is 91 A
grade Oxy free. I deliver gas for a living. P.S. owners manual says 4.0
runs worse on higher octane.
I sent the cylinder head out to get checked for cracks, acid dipped &
milled -0.10″ & I also used the mopar performance slim head gasket that’s
-0.08 slimmer than O.E
And the reason why I chose to do this job is to unleash the hidden HP/TQ
and im a very happy 4.0 owner now B-)
That is a nice job you have done with the upgrades. You should try running
race fuel or AVGAS (aviation 100LL (100 octane low lead)). With the higher
compression I’ll bet it would run even better with the 100 octane gas.
Correct they should last 100k, but I found out the reason why I had to
change them out so quickly the engine was running to lean so I took out
those injectors that you seen in the video and swapped them out for the GM
LT1 6 hole and reset the E.C.M to relearn the air fuel mix. It seemed I
fixed the problem but im not sure I have to get a Air/Fuel mix Guage and
ill know for shure but I would really like to get it tuned & put it on the
dyno, so far it passes my butt dyno B-)
Hey man just a warning autolite plugs have a bad reputation of snapping off
in the head when you take them out. I would recommend you replace them with
champions or just take them out and put some anti-seize on the threads. I
am saying this from not only reviews but also several personal experiences
on multiple vehicles.
Wow what kind of repairs? We easily have no problem making it to 300k with
these indestructible 4.0’s the only way you won’t make it is you overheat
them or run them with out oil or oil pressure
Nice Jeep bum, I had the same issue with my cherokee, twice. The first time
I put in Bosch, but after about year I had misfires, then one just blew…
I then went to e3’s thinking not only will I get better performance but
better gas milege too, and I did, for about 10 days, then I got mega
misfires. Finally, I spoke to a few Jeep heads and they all told me that
Jeep (at least my year, 99) were finicky, they craved original parts
original specs. Copper Champs, no frills, perfect now….
I think right now I’m planning on just making it to 300,000. OVer the last
two years Ive spent 3 k in repairs. Some of those repairs were done twice
because the person who did them the first time did them wrong send me an
email dukefamily1@gmail.com
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Your probably right in your own way but the difference between my 4.0 and
the 4.0 in the owners manual is that mine is a highly modified 4.0! So I
feed it no less than 93 octane!
Your 93 oxy is the same garbage as 87 oxy. The only real premium is 91 A
grade Oxy free. I deliver gas for a living. P.S. owners manual says 4.0
runs worse on higher octane.
I sent the cylinder head out to get checked for cracks, acid dipped &
milled -0.10″ & I also used the mopar performance slim head gasket that’s
-0.08 slimmer than O.E
And the reason why I chose to do this job is to unleash the hidden HP/TQ
and im a very happy 4.0 owner now B-)
These motors where built around using champion spark plugs for ignition, so
i always use what they recommend :P
I HAVE THE SAME YEAR XJ MAN! WHAT DID YOU MACHINE THE HEADS FOR? WHAT
PERFORMANCE ENHANCEMENT DID THAT GIVE YOU?
That is a nice job you have done with the upgrades. You should try running
race fuel or AVGAS (aviation 100LL (100 octane low lead)). With the higher
compression I’ll bet it would run even better with the 100 octane gas.
Badass mods man she looks sweet.. Just picked up a 93 sport with 140k..
Gonna do some mods myself where do you get your info?
Correct they should last 100k, but I found out the reason why I had to
change them out so quickly the engine was running to lean so I took out
those injectors that you seen in the video and swapped them out for the GM
LT1 6 hole and reset the E.C.M to relearn the air fuel mix. It seemed I
fixed the problem but im not sure I have to get a Air/Fuel mix Guage and
ill know for shure but I would really like to get it tuned & put it on the
dyno, so far it passes my butt dyno B-)
Thanks alot I get all my info from the cherokee forums
You need to have your own show! lol Keep posting!
Ohh hell yeah with out a doubt…but this is my DD and race gas @ $5 a
gallon will leave me broke!
Sick XJ man nice and clean 🙂
mine is green like yours. How many miles on yours? Im at 189k
Hey man just a warning autolite plugs have a bad reputation of snapping off
in the head when you take them out. I would recommend you replace them with
champions or just take them out and put some anti-seize on the threads. I
am saying this from not only reviews but also several personal experiences
on multiple vehicles.
That’s exactly what I used when I put them in B-)
Wow what kind of repairs? We easily have no problem making it to 300k with
these indestructible 4.0’s the only way you won’t make it is you overheat
them or run them with out oil or oil pressure
I have to change em like every 3 to 4 weeks this is my daily driver and it
currently has 188,xxx miles
Our 4.0s love strictly copper core plugs
Nice Jeep bum, I had the same issue with my cherokee, twice. The first time
I put in Bosch, but after about year I had misfires, then one just blew…
I then went to e3’s thinking not only will I get better performance but
better gas milege too, and I did, for about 10 days, then I got mega
misfires. Finally, I spoke to a few Jeep heads and they all told me that
Jeep (at least my year, 99) were finicky, they craved original parts
original specs. Copper Champs, no frills, perfect now….
how often have you been changing them?
Thanx B-)
Spark plugs should last 100K. I have no mods on mine. Mine is all stock.
I think right now I’m planning on just making it to 300,000. OVer the last
two years Ive spent 3 k in repairs. Some of those repairs were done twice
because the person who did them the first time did them wrong send me an
email dukefamily1@gmail.com