Thanks for the suggestions! I'll start with the heat wrap and see if
that works.

On Jan 3, 1:30 pm, "Jeff Strickland" <c...@yahoo.com> wrote:
> With a misfire, I'd be looking at the plug wires or coil. I'd check plug
> wires if there was a distributor, or I'd look at the coil if there was a
> separate coil for each cylinder, or a coil for every two cylinders.
>
> "01XJ" <adam.tsacouman...@gmail.com> wrote in messagenews:1167779855.090317.153570@v33g2000cwv.g ooglegroups.com...
>
> >I just started experiencing a rough idle on my 2001 Cherokee (78k
> > miles). My engine light went on a little after that with the P0303
> > code. I just replaced the spark plugs, but that didn't help anything.
> > I was
> > thinking about changing the ignition coil or fuel injector. One other
> > possibility I was
> > thinking was checking the cylinder compression (maybe a gasket leak?).
> > Anyone have any suggestions?

 

Thanks for the suggestions! I'll start with the heat wrap and see if
that works.

On Jan 3, 1:30 pm, "Jeff Strickland" <c...@yahoo.com> wrote:
> With a misfire, I'd be looking at the plug wires or coil. I'd check plug
> wires if there was a distributor, or I'd look at the coil if there was a
> separate coil for each cylinder, or a coil for every two cylinders.
>
> "01XJ" <adam.tsacouman...@gmail.com> wrote in messagenews:1167779855.090317.153570@v33g2000cwv.g ooglegroups.com...
>
> >I just started experiencing a rough idle on my 2001 Cherokee (78k
> > miles). My engine light went on a little after that with the P0303
> > code. I just replaced the spark plugs, but that didn't help anything.
> > I was
> > thinking about changing the ignition coil or fuel injector. One other
> > possibility I was
> > thinking was checking the cylinder compression (maybe a gasket leak?).
> > Anyone have any suggestions?

 

Thanks for the suggestions! I'll start with the heat wrap and see if
that works.

On Jan 3, 1:30 pm, "Jeff Strickland" <c...@yahoo.com> wrote:
> With a misfire, I'd be looking at the plug wires or coil. I'd check plug
> wires if there was a distributor, or I'd look at the coil if there was a
> separate coil for each cylinder, or a coil for every two cylinders.
>
> "01XJ" <adam.tsacouman...@gmail.com> wrote in messagenews:1167779855.090317.153570@v33g2000cwv.g ooglegroups.com...
>
> >I just started experiencing a rough idle on my 2001 Cherokee (78k
> > miles). My engine light went on a little after that with the P0303
> > code. I just replaced the spark plugs, but that didn't help anything.
> > I was
> > thinking about changing the ignition coil or fuel injector. One other
> > possibility I was
> > thinking was checking the cylinder compression (maybe a gasket leak?).
> > Anyone have any suggestions?

 

Jeff, no plug wires or dist cap on an 00 and 01. Coil rail with three coil
packs.

Carl


"Jeff Strickland" <crwlr@yahoo.com> wrote in message
news:OfidnY5u3NmnmQHYnZ2dnUVZ_h6jnZ2d@ez2.net...
> With a misfire, I'd be looking at the plug wires or coil. I'd check plug
> wires if there was a distributor, or I'd look at the coil if there was a
> separate coil for each cylinder, or a coil for every two cylinders.
>
>
>
> "01XJ" <adam.tsacoumangos@gmail.com> wrote in message
> news:1167779855.090317.153570@v33g2000cwv.googlegr oups.com...
>>I just started experiencing a rough idle on my 2001 Cherokee (78k
>> miles). My engine light went on a little after that with the P0303
>> code. I just replaced the spark plugs, but that didn't help anything.
>> I was
>> thinking about changing the ignition coil or fuel injector. One other
>> possibility I was
>> thinking was checking the cylinder compression (maybe a gasket leak?).
>> Anyone have any suggestions?
>>
>

 

Jeff, no plug wires or dist cap on an 00 and 01. Coil rail with three coil
packs.

Carl


"Jeff Strickland" <crwlr@yahoo.com> wrote in message
news:OfidnY5u3NmnmQHYnZ2dnUVZ_h6jnZ2d@ez2.net...
> With a misfire, I'd be looking at the plug wires or coil. I'd check plug
> wires if there was a distributor, or I'd look at the coil if there was a
> separate coil for each cylinder, or a coil for every two cylinders.
>
>
>
> "01XJ" <adam.tsacoumangos@gmail.com> wrote in message
> news:1167779855.090317.153570@v33g2000cwv.googlegr oups.com...
>>I just started experiencing a rough idle on my 2001 Cherokee (78k
>> miles). My engine light went on a little after that with the P0303
>> code. I just replaced the spark plugs, but that didn't help anything.
>> I was
>> thinking about changing the ignition coil or fuel injector. One other
>> possibility I was
>> thinking was checking the cylinder compression (maybe a gasket leak?).
>> Anyone have any suggestions?
>>
>

 

Jeff, no plug wires or dist cap on an 00 and 01. Coil rail with three coil
packs.

Carl


"Jeff Strickland" <crwlr@yahoo.com> wrote in message
news:OfidnY5u3NmnmQHYnZ2dnUVZ_h6jnZ2d@ez2.net...
> With a misfire, I'd be looking at the plug wires or coil. I'd check plug
> wires if there was a distributor, or I'd look at the coil if there was a
> separate coil for each cylinder, or a coil for every two cylinders.
>
>
>
> "01XJ" <adam.tsacoumangos@gmail.com> wrote in message
> news:1167779855.090317.153570@v33g2000cwv.googlegr oups.com...
>>I just started experiencing a rough idle on my 2001 Cherokee (78k
>> miles). My engine light went on a little after that with the P0303
>> code. I just replaced the spark plugs, but that didn't help anything.
>> I was
>> thinking about changing the ignition coil or fuel injector. One other
>> possibility I was
>> thinking was checking the cylinder compression (maybe a gasket leak?).
>> Anyone have any suggestions?
>>
>

 

Interesting that you posted this at this time. I have a 2001 TJ with the 2.5
L with the same problem except I have a P0302 code. It is skipping bad. I
am lucky enough to have an independent shop locally with a good, smart,
reliable crew who has never tried to stiff me on any repair work. Dropped
it off there yesterday and called them today to get some news. They found
that one of the bridges across the valve rocker arms on cylinder two had
broken. Part will be in tomorrow. Just more information for you in case you
run into a dead end eventually. Hope this helps.
Les


"01XJ" <adam.tsacoumangos@gmail.com> wrote in message
news:1167779855.090317.153570@v33g2000cwv.googlegr oups.com...
>I just started experiencing a rough idle on my 2001 Cherokee (78k
> miles). My engine light went on a little after that with the P0303
> code. I just replaced the spark plugs, but that didn't help anything.
> I was
> thinking about changing the ignition coil or fuel injector. One other
> possibility I was
> thinking was checking the cylinder compression (maybe a gasket leak?).
> Anyone have any suggestions?
>

 

Interesting that you posted this at this time. I have a 2001 TJ with the 2.5
L with the same problem except I have a P0302 code. It is skipping bad. I
am lucky enough to have an independent shop locally with a good, smart,
reliable crew who has never tried to stiff me on any repair work. Dropped
it off there yesterday and called them today to get some news. They found
that one of the bridges across the valve rocker arms on cylinder two had
broken. Part will be in tomorrow. Just more information for you in case you
run into a dead end eventually. Hope this helps.
Les


"01XJ" <adam.tsacoumangos@gmail.com> wrote in message
news:1167779855.090317.153570@v33g2000cwv.googlegr oups.com...
>I just started experiencing a rough idle on my 2001 Cherokee (78k
> miles). My engine light went on a little after that with the P0303
> code. I just replaced the spark plugs, but that didn't help anything.
> I was
> thinking about changing the ignition coil or fuel injector. One other
> possibility I was
> thinking was checking the cylinder compression (maybe a gasket leak?).
> Anyone have any suggestions?
>

 

Interesting that you posted this at this time. I have a 2001 TJ with the 2.5
L with the same problem except I have a P0302 code. It is skipping bad. I
am lucky enough to have an independent shop locally with a good, smart,
reliable crew who has never tried to stiff me on any repair work. Dropped
it off there yesterday and called them today to get some news. They found
that one of the bridges across the valve rocker arms on cylinder two had
broken. Part will be in tomorrow. Just more information for you in case you
run into a dead end eventually. Hope this helps.
Les


"01XJ" <adam.tsacoumangos@gmail.com> wrote in message
news:1167779855.090317.153570@v33g2000cwv.googlegr oups.com...
>I just started experiencing a rough idle on my 2001 Cherokee (78k
> miles). My engine light went on a little after that with the P0303
> code. I just replaced the spark plugs, but that didn't help anything.
> I was
> thinking about changing the ignition coil or fuel injector. One other
> possibility I was
> thinking was checking the cylinder compression (maybe a gasket leak?).
> Anyone have any suggestions?
>

 

Carl wrote:
> Jeff, no plug wires or dist cap on an 00 and 01. Coil rail with three
> coil packs.

Some rails can develop internal leaks that cause misfire. If you can, try
swapping packs and see if the problem moves. If it moves, it's the pack.
If it doesn't move, it could be the coil rail.

If you have a good rpm gauge or ears you can try this.
With the engine running, disconnect the injectors one
at a time (just one at any one time though) and listen.
There should be exactly the same drop in rpm. If you lift
#3 and there is little drop then the injector or the feed
to that injector might be bad. A mechanic stethescope placed
on each injector will also give you a clue as to how they
are working. They should have a clanging sound and not
a dull thunk.

Also remember, with coil rails and packs, plugs fire in pairs.
I think this is the correct pairing. don't have the schematic
to look at.

1 5 3 6 2 4
1 6
5 2
3 4


--
DougW