Tune Up on a 99 GC? - JeepForum.com
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post #1 of 3 Old 07-16-2004, 09:50 AM Thread Starter
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Location: Springville Utah
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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.
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post #2 of 3 Old 07-16-2004, 09:57 AM
Myrtle Beach
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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.
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post #3 of 3 Old 07-17-2004, 12:45 PM
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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)
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