Hey forum peeps,
New to the forum and hoping to get some info. I recently purchased a 05 Jeep Grand cherokee with a 5.7 hemi. 150K miles and a very clean vehicle overall.
It had a misfire on cylinder 5. I replaced all the coil packs, all 16 plugs, wires and the codes cleared. However, the vehicle is very sluggish. It idles smooth, runs good. But i can tell something is off. I am mechanically inclined and can do most everything on my own. I have mechanical experience but am perplexed. I did a 0-60 test and it took 13 seconds to get there. Some more history: I have replaced the following on the vehicle: AB sensors, oil, plugs, wires, coil packs adn some misc cosmetic stuff. Ive read around about fuel pressure issues, injector issues, ect. I am new to the world of hemi's. We also own a bae model 07 Cherokee and love it. It has been well maintained and runs like a champ.
Can anyone point me in a direction to figure this out? It has no current engine codes and outside looking in, runs fine. It is also a 4x4.

Thanks in advance.

Thedub

 

1) this is the XJ forum, you might have better response re that engine if you post on the Grand Cherokee forum.

2) in any case it could be anything from the engine to the brakes. You need to do some diagnostics. To focus on the engine I would do a compression check and fuel pressure check.

 

Thank you! Ive now posted this where it needs to go.
Have a good day!