Have a 2004 jeep grand cherokee larado miss firing.changed spark plugs and coil pack. Still have misfire. Any suggestions?

Carefully check your routing and make sure that all spark plug wires are attached to the correct spark plugs otherwise your firing order will be mixed up and cause the issue you are having. Also make sure that the wires are firmly seated on the coil packs or distributor, whichever is on your vehicle.

are you doing spark or timing a cam? what? what is JOB?
it dont matter, the engine, ecu does that, (magic)
but if it has a coil pack like my 3.8 then the coil pack must
be wire right and is marked. clearly on the pack.
they have USA jeeps and Export. country never stated here. sad huh?
and use differnent spark systems (3 types used, but 2 common)
per below.

v6.
is this not a Cheokee? the non Grand ended in 2004. so...
ill go with GC 2005, v6 3.7L
the v6 began in 2005, not 2004, but, maybe yours is the first./

the 3.7 has coil over plug, spark, 6 coils.
and the harness is fixed to those coil so all firing order are
dictated in the ECU/PCM (hard coded)

VIN engine code, K. (not stated)
http://www.fixya.com/cars/t13893405-firing_order_diagram_3_7l_jeep_2006

and already asked, and answered .

my 3.8 (2004) jeep.
is 1,2,3,4,5,6
and is like this.

mine uses wasted spark system.

http://www.fixkick.com/look/odds-ends/jeep/2008-JK/slideshow/firing-order.JPG


so post VIN, or tell what engine is really there.
and the true year. or build date (sticker)

so my answer is.. 2005 GC, 3.7L V6, not I-6
it has 6 cops, "coil over plugs" 6 induction coils
and runs same firing order, as the old I6 did.
1-5-3-6-2-4
but the I6 4.0liter runs a coil pack and is quite different.
these;


times 6
all laced in, hard.

the coil. ? older post.
the PCM reports even one drop out of 10 , on the CKP or CMP sensors. 99.9% of these changed are good.
why not tell me what you have,? full symptoms and evidence.
got P030x misfiring? are you even using a scan tool,? or working blind.
may be its the coil.?
can can you feel the misfiring.c
can you see the engine shake? all of this is evidence.
do not miss out on that.
does the scan too shop pending misfire codes?
stored codes, or codes while driving, learn to use the scan tool.
do a 60k mile tune up yet?
your engine is not COP coils like the V8
its COIL rail that is a COIL pack with 3 coils inside
that runs 2 sparks each called WASTED park.
so did you try new sparkplugs(dah)first then new coil pack wires HV
next , then a new coil pack last.
start with the cheap spark plug and wires, (called a tuneup)
then pop for coil pack./
misfire can be clogged or leaking injectors too, and that ill skip
with out you using the scan tool fully.

PROBLEM COULD BE DISTRIBUTOR OR CAMSHAFT SENSOR.ALSO CHECK IGNITION FUSE.

focusing on the coil packs but no mention of changing or checking the injectors or wiring to those injectors

yah direct ignition coil pack does away for the need a a distributer cap and rotor.much higher energy ignition system where the computer tell when to fire.if that helps.not hard to change.as long as you change them one at a time so you don't screw up the order.

IF MISFIRING IT COULD BE WRONG SPARK PLUGS OR WRONG PLUGS GAPS OR BAD COILS.BESURE TO CHECK VECHICLE SPECFICATION FOR YOUR VECHICLE TYPE PLUGS.

If you havent changed the spark plugs, id start there.

you need to change the coil on# 3

You say you changed the cam sensor. A1391 code is a crank sensor on the top of the trans. bell housing.