Tune Up on a 99 GC? - JeepForum.com
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 > ZJ Grand Cherokee Forum > Tune Up on a 99 GC?

Forever Wave Flags at JeepHutRubicon Express lift kits w/shocks are on sale!ORS4x4: New Product!

Unread 07-16-2004, 10:50 AM   #1
Registered User
Join Date: Feb 2002
Location: Springville Utah
Posts: 216
Tune Up on a 99 GC?

My wife's 99 GC has just hit 90k. I don't normally do anything with it, I only drive it once in a while. I drove it the other day and it just does not seem to be running as smooth as it used to. We pretty much keep up on the regular oil changes, and Transmission fluid changes. I really haven't had to do anything on besides the brakes. So this weekend I am planning a tune up.
I am going to replace the plugs, wires, airfilter, and run some injector cleaner through it. Anything else that you guys can think of that I should do?


03 Rubicon- Teraflex 3T, 285/75 MTRs.
99 WJ (Wife's)--She has tow hooks too.
77 CJ7--Everything works but the heater, and man is she Ugly.
MFairbourn is offline   Reply With Quote Quick reply to this message
Unread 07-16-2004, 10:57 AM   #2
Myrtle Beach
Registered User
Join Date: Jul 2004
Location: Myrtle Beach, SC
Posts: 542
I am pretty sure your WJ has a coil over plug system-meaning you can't change the wires b/c it does not have any. I just changed the plugs on mine and the old plugs were really worn down (gap had opened up to .50-should be .40) and it helped with the idle and acceleration. I used champion truck plugs. I would also look to flush the cooling system. I would stay away from the Dex-cool though and stick with the green stuff. It might be a good idea to get a professional fuel system cleaning (from a mechanic) to rid the system of carbon deposits. I would recommend this before you change the plugs. Other than that it sounds like you got it.
Myrtle Beach is offline   Reply With Quote Quick reply to this message
Unread 07-17-2004, 01:45 PM   #3
I ate what?
10achik's Avatar
1999 WJ 
Join Date: Sep 2003
Location: STL (IL side)
Posts: 8,341
Got the same JEEP and I just did my tune up about 6 months ago at 76K. Added some NGK V power plugs and did a through cleaning of the throtle body/IAC/TPS and ran some seafoam through the oil and gas not that it was running bad, but it PM is always cheaper than fixing something after it breaks.

BTW the NGK's are great plugs and don't cost an arm and a leg

99 GC Limited - 4.7L HO V8, 6.5" IRO HC LA lift, F&R D44s locked & trussed, 242HD, IRO TC Skid, KMA Bumper, 35's
2006 Saturn Redline -2.0L Eaton supercharged I4, GMPP Stage 2, Custom Tune, AEM CAI, Ebiach Pro Kit w/ swaybars, EVO Ventus V12s (13.76 @ 103.85)
2006 Pontiac G6 GTP
2012 Nissan Juke - (hers)
2000 SV650 - naked, integrated tail light, sliders, corbin, pilot roads, RK chain & sprokets, D&D full exhaust, FactoryPro Stage I jet kit, +4 Ignition Advancer, Barnett race clutch
2006 Triumph America 900 - Full Dresser

January 2009 Grand Cherokee of the Month (GCOTM)
10achik is offline   Reply With Quote Quick reply to this message

Quick Reply

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Thread Tools

Suggested Threads
  • IL 6 Tune-Up - ZJ Grand Cherokee Forum (15 replies)
  • Bad Tune Up - ZJ Grand Cherokee Forum (16 replies)
  • Tune Up? - ZJ Grand Cherokee Forum (4 replies)
  • tune up - ZJ Grand Cherokee Forum (15 replies)
  • tune-up - ZJ Grand Cherokee Forum (8 replies)

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.