RobGADV

Hey... new here... refugee from another Jeep forum that shall remain nameless...

I have a 2002 Grand Cherokee Overland (4.7LHO) that I bought last March. Has 128k. Have done all the basic maintenance -- all fluids incl trans, diff, transfer case, fresh belt, air filter, antifreeze. Just last week I started getting a misfire on Cyl 8 code. I clear it and it comes right back. Today I swapped coil packs between 6 and 8 and code is still there on #8.

It seems to run fine once warm. On a cold morning, it will idle and run a little rough (just a little) but again, once warm, is absolutely fine. Did 30 miles of technical off-road yesterday and it did great at low speeds, not a single stumble.

So now thinking it could be the fuel injector. Anything else I should consider? If it IS the injector, is ti okay to replace just one or should I do all eight? That could get expensive. I dumped a bottle of Sea Foam in the tank yesterday when I filled up.. I suppose that could fix it if it's just a dirty injector. I've already run a few cans of it through it since I bought it. I run 91 all the time because I like the extra power and have the Superchips programmer so it's either in Performance Tune or Tow Tune, both of which require 91.

Any suggestions would be appreciated!

Rob