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Unread 06-07-2010, 01:56 PM   #1
tyaquinto
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2004 WJ 
 
Join Date: Jun 2010
Location: tallmadge, ohio
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FUEL ECONOMY... even on highway

Hello,

My WJ like all, gets crappy MPG's.. I can accept this, but the problem is even on the freeway i still get about 12.. infact sometimes my freeway MPG is less than the city.. I have even tried driving like an old man..

This happened even when it was all stock.. so its not the add ons that have completely added to this.

I just did plugs, even a new coil pack, new fuel pump.. i am thinking maybe o2's or injectors?

I am new to this as well.. so sorry if this same post already appears..

todd

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Unread 06-07-2010, 02:56 PM   #2
tyaquinto
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meant to say.. fuel filter.. not pump
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Unread 06-07-2010, 03:33 PM   #3
straty1987
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how about air filter, all the oils?

check to see if any calibers are sized or if you have any codes
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Unread 06-07-2010, 04:12 PM   #4
LordHobbit
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What mileage? What maintenance has been performed?

You have an I6 not v6.

Could be front hubs. Mine are also suspect, but they are fine when I test them.

x2 on brakes and also check the parking brake isn't seizing.

Maybe a clogged cat or otherwise poor exhaust, or intake. Has the throttle body been cleaned ever?
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Unread 06-08-2010, 08:32 AM   #5
tyaquinto
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Location: tallmadge, ohio
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woops on the v6.. not sure why i put a v there.. only reason i bought this one was for the i6 haha..

air filter is brand new, oil is new, i am gonna check the codes see if anything is showing up, milage is 97k but i have had the vehical since it was in the 60k range.

i'll check the rear parking brake.

what would be wrong with the front hubs?

Throttle body has not been cleaned, and i will check out the cat, from tha cat back is new too gibson exhaust..

You think a bad o2 could be?

thanks all
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Unread 06-08-2010, 02:16 PM   #6
redfoxbody
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how fast do you drive on the highway?

I have the 4.0 too and anything over 68MPH for me and my gas mileage falls off the face of the earth lol

I would do a basic tuneup if you havent already, spark plugs, wires, cap, rotor etc...
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Unread 06-08-2010, 02:29 PM   #7
LordHobbit
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Could be an o2, maintenance says every 80k I believe. If you don't have cali emissions you'll have two o2s. an upstream and downstream. Did you put the one after the cat back in after the exhaust work??

Hubs are basically the front bearings and can wear out. This is probably the best writeup on it here on the forum: http://www.jeepforum.com/forum/f13/h...w-pics-377208/

I'm not saying they are bad, but it's possible. I check mine by taking off the wheel, removing the caliper and then spinning the rotor around to see if it binds or feels bad. So far mine haven't so I haven't replaced them yet.

If you do tuneup, get a cap and rotor with brass contacts.
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93 red ZJ 190k 4.0. Spent more money than I should have ...

Isn't red the only color a vehicle should be?
If at first you don't succeed, use more speed.
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Unread 06-08-2010, 02:37 PM   #8
tyaquinto
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Location: tallmadge, ohio
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the odd thing is on the free what jeep has always had a hard time at 65.. so i go about 60ish.. if you go 70 its fine, i usually dont. but 65 is hard to obtain unsure why.. its like 60 or 70 but no 65..

i dont drive fast at all..
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Unread 06-08-2010, 02:46 PM   #9
Apollo21
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you should be able to get close to 22mpg at 60mph
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Unread 06-08-2010, 04:22 PM   #10
straty1987
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is the diff & TV fluid old
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