2002 Grand Cherokee 9.4 miles per gallon. Need Help!!! - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Grand Cherokee & Commander Forums > WJ Grand Cherokee Forum > 2002 Grand Cherokee 9.4 miles per gallon. Need Help!!!

2003-2004 Jeep Grand Cherokee Headlight Dark Background wiOPTIC ARMOR WINDOWS all sale now !!!!!!!!1999-2004 Jeep Grand Cherokee Wheel Bearing & Hub Asse

Reply
Unread 03-11-2012, 09:21 PM   #1
JeepFuel2002
Registered User
2002 WJ 
 
Join Date: Mar 2012
Location: Brooklyn, New York
Posts: 8
2002 Grand Cherokee 9.4 miles per gallon. Need Help!!!

Recently bought a 2002 Grand Cherokee Laredo with 117,000 miles. 4.0 L Straight 6 cylinders. My problem is that it is spending too much gas. It averages between 9.3 and 9.7 mpg and I'm not pushing it hard. Any ideas, advice on what could be wrong with it?

JeepFuel2002 is offline   Reply With Quote
Unread 03-11-2012, 10:26 PM   #2
S8NNG8
Registered User
1995 XJ Cherokee 
 
Join Date: Feb 2012
Location: Helena, Montana
Posts: 3,527
I have a '95 XJ, but I have the same engine, kind of. Anyway, I just replaced my plugs, wires, and dist. cap for $75 & gained about 5 mpg. You may have many issues, but this could be one of them.
__________________
D3<!L!>3D
S8NNG8 is offline   Reply With Quote
Unread 03-12-2012, 07:34 AM   #3
JeepFuel2002
Registered User
2002 WJ 
 
Join Date: Mar 2012
Location: Brooklyn, New York
Posts: 8
Quote:
Originally Posted by S8NNG8
I have a '95 XJ, but I have the same engine, kind of. Anyway, I just replaced my plugs, wires, and dist. cap for $75 & gained about 5 mpg. You may have many issues, but this could be one of them.
I just replaced the plugs. I'm going to replaced the wires, etc and see if that works for me. Thanks for responding. Will keep posting if anything.
JeepFuel2002 is offline   Reply With Quote
Unread 03-12-2012, 10:36 AM   #4
duanewhatley
Registered User
1999 WJ 
 
Join Date: Jun 2009
Location: Kimberly, Alabama
Posts: 492
Quote:
Originally Posted by JeepFuel2002

I just replaced the plugs. I'm going to replaced the wires, etc and see if that works for me. Thanks for responding. Will keep posting if anything.
No plug wires, each plug has its own coil.
duanewhatley is offline   Reply With Quote
Unread 03-12-2012, 10:38 AM   #5
ChrisHager
Web Wheeler
 
ChrisHager's Avatar
2004 WJ 
 
Join Date: Jan 2011
Location: Springfield, Illinois
Posts: 3,680
Change the fluids/filters.
Fuel filter may be clogged up - slap a new one on.
Champion copper plugs work best. What type did you use?
__________________
His: 2004 WJ - OME HD 'Kolak' Lift - Build Thread
His: 1979 J-10 - 3" on 33s - Build Thread
Hers: 2000 TJ

ChrisHager's 'Grilled' Thread

WJ Torque Specs

Quote:
Originally Posted by tommyooooooh View Post
But ChrisHager makes me want to poor water on a burning bucket of gasoline now just out of curiosity.
Quote:
Originally Posted by billzcat1 View Post
The latest lift kit from Rough Country? :D
Quote:
Originally Posted by Jeeples View Post
Your symptoms sounds just like what it does when it's not doing what it should because of how it is.
ChrisHager is online now   Reply With Quote
Unread 03-12-2012, 10:39 AM   #6
Merc1973
Registered User
2002 WJ 
 
Join Date: Jun 2008
Location: Ellicott city, MD
Posts: 1,621
Try Fuel filter, air filter, trans fluid level?

Get some Chevron Techron injector cleaner before the fuel filter change.
__________________
2002 WJ Ltd. 4.7 V8, QuadraDrive
1973 Mercury Cougar Xr7 convertible 351CJ, C6, 9" rear
1970 Kaiser-Jeep M35A2 W/OW 6x6 Multifuel D-Turbo.


ΜΟΛΩΝ ΛΑΒΕ!
Merc1973 is offline   Reply With Quote
Unread 03-12-2012, 02:42 PM   #7
JeepFuel2002
Registered User
2002 WJ 
 
Join Date: Mar 2012
Location: Brooklyn, New York
Posts: 8
The plugs that I used were champion and yeah there's no wires (coils). I'm going to use the fuel injector cleaner, probably change the coils; the only thin is that I don't have a misfire or check engine light. And I'm going to replace the fuel filter
JeepFuel2002 is offline   Reply With Quote
Unread 03-12-2012, 02:45 PM   #8
JeepFuel2002
Registered User
2002 WJ 
 
Join Date: Mar 2012
Location: Brooklyn, New York
Posts: 8
By the way the air filter is clean. Transmission fluid level is also good. And once again thank you for all the help.
JeepFuel2002 is offline   Reply With Quote
Unread 03-12-2012, 05:59 PM   #9
billzcat1
Chicken in a Turkey Suit
2003 WJ 
 
Join Date: Oct 2008
Location: Redmond, WA
Posts: 8,544
Do you have any brakes dragging? What type of driving? Short trips? Hills? Highway/City? Probably needs O2 sensors at 117k if they are still original.
billzcat1 is offline   Reply With Quote
Unread 03-13-2012, 11:59 AM   #10
specia1k
Registered User
2004 WJ 
 
Join Date: Sep 2011
Location: Jacksonville, FL
Posts: 314
Champion Copper Plugs, WIX Fuel Filter, Throttle Body Cleaner, Seafoam in fuel to clean injectors, Air pressure 33-35lbs (I prefer 35) in tires, Air Filter, Oxygen Sensors (even if there not throwing a code). Is your engine getting up to temperature? Reason I asked, our '02 had a thermostat that was stuck in the open position. So it never got to optimal operating temperature. So the PCM sends more fuel to the engine, to get the temp up, but with open thermostat, it's constantly cooling the engine, while the PCM sends more fuel, i.e. poor mileage. When I looked at the thermostat, stuck wide open. Changed it and MPG jumped back to 18-20 mpg. Was in low teens prior.
__________________
2004 Jeep Grand Cherokee Limited 2x4 4.0L
2002 Jeep Grand Cherokee Sport 2x4 4.0L
1998 Jeep Grand Cherokee Laredo 2x4 4.0L
"Three daughters, three Jeeps"
specia1k is offline   Reply With Quote
Unread 03-13-2012, 12:24 PM   #11
1AAdam
Registered User
2000 WJ 
 
Join Date: Jun 2010
Location: Massachusetts
Posts: 1,573
i have to do a few of the things mentioned above. alignment and stuff u would want to check too but that wouldn't cause that kind of mileage.
__________________
Adam
1aauto.com
888-844-3393
1AAdam is offline   Reply With Quote
Unread 03-13-2012, 02:33 PM   #12
AGDubyaJ
Registered User
1998 XJ Cherokee 
 
Join Date: Oct 2010
Location: San Luis Obispo, CA, CA
Posts: 1,028
is your check engine light on?
__________________
98 XJ- 4.0L, NP231, AW4, chryco 8.25, 4.5" mid arm 3-link, 285/75 Herc terra tracs on moabs, V8 ZJ tie rod, fabbed bumpers...
AGDubyaJ is offline   Reply With Quote
Unread 03-13-2012, 04:04 PM   #13
porrsher
Registered User
1994 ZJ 
 
Join Date: Mar 2005
Location: Jefferson,GA, Georgia
Posts: 589
unhitch that travel trailer you are pulling!



Good lawwwrd! 9 mpg? I get 12 towing at 60 and I thought I was in trouble!
__________________
1994 Hunter Green ZJ 5.2L Quadratrac
228k Miles, 2" BB.
2002 Slate Grey Grand Cherokee Overland
161k Bone Stock
2008 Black JK Sahara Unlimited (Love it!)
porrsher is offline   Reply With Quote
Unread 03-13-2012, 04:18 PM   #14
JeepFuel2002
Registered User
2002 WJ 
 
Join Date: Mar 2012
Location: Brooklyn, New York
Posts: 8
I'm going to get my coils. Now the engine started shaking as if it has a misfire when I start the car and then goes away in few seconds.
JeepFuel2002 is offline   Reply With Quote
Unread 03-13-2012, 04:30 PM   #15
SkipStr
Registered User
2000 WJ 
 
Join Date: Feb 2012
Location: Bay Shore, NY
Posts: 51
Quote:
Originally Posted by JeepFuel2002 View Post
I'm going to get my coils. Now the engine started shaking as if it has a misfire when I start the car and then goes away in few seconds.
That could be your fuel rail losing pressure . May be a bad check valve in the fuel pump. See if you can borrow a fuel pressure gauge and see if the pressure at the rail drops when the jeep is not running.
SkipStr is offline   Reply With Quote
Reply
Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.