Liberty - Misfire
 

Some time ago, I posted to this group about a chronic problem with my 2003
Liberty - giving P300 codes (misfire in multiple cylinders). We finally
noticed a pattern that it only occured when the AC was running. The dealer
started running their analyzer with the AC compressor running, and not
running, and found a substantial difference that did not appear with other
vehicles. Noticing that the compressors on the new Libertys on the lot were
at least 4 EC levels later (this from the part number), they decided to swap
out the compressor. What was unusual, is that the Denver Mopar depot was
over 50 compressors back-ordered! Rather than making me wait, the dealer
pulled a compressor from a new vehicle on their lot. The misfire problem
has not occured since.

Does this make sense to anybody? Also, has anybody heard any problems with
the compressors? I'm told that Denver is almost never back-ordered on this
part.

Thanks in advance,

Bruce

Re: Liberty - Misfire
 

Bruce Yelen did pass the time by typing:
> Some time ago, I posted to this group about a chronic problem with my 2003
> Liberty - giving P300 codes (misfire in multiple cylinders). We finally
> noticed a pattern that it only occured when the AC was running. The dealer
> started running their analyzer with the AC compressor running, and not
> running, and found a substantial difference that did not appear with other
> vehicles. Noticing that the compressors on the new Libertys on the lot were
> at least 4 EC levels later (this from the part number), they decided to swap
> out the compressor. What was unusual, is that the Denver Mopar depot was
> over 50 compressors back-ordered! Rather than making me wait, the dealer
> pulled a compressor from a new vehicle on their lot. The misfire problem
> has not occured since.
>
> Does this make sense to anybody? Also, has anybody heard any problems with
> the compressors? I'm told that Denver is almost never back-ordered on this
> part.

Sense... sorta...

Could have been due to the clutch pulling too much current or feeding
back electrical noise that interfered with the ignition or computer
circuit. But your right, that does sound like a mighty long stretch. :/

Anyhoo, glad your Jeep is back and running.

--
DougW

Re: Liberty - Misfire
 

Bruce Yelen did pass the time by typing:
> Some time ago, I posted to this group about a chronic problem with my 2003
> Liberty - giving P300 codes (misfire in multiple cylinders). We finally
> noticed a pattern that it only occured when the AC was running. The dealer
> started running their analyzer with the AC compressor running, and not
> running, and found a substantial difference that did not appear with other
> vehicles. Noticing that the compressors on the new Libertys on the lot were
> at least 4 EC levels later (this from the part number), they decided to swap
> out the compressor. What was unusual, is that the Denver Mopar depot was
> over 50 compressors back-ordered! Rather than making me wait, the dealer
> pulled a compressor from a new vehicle on their lot. The misfire problem
> has not occured since.
>
> Does this make sense to anybody? Also, has anybody heard any problems with
> the compressors? I'm told that Denver is almost never back-ordered on this
> part.

Sense... sorta...

Could have been due to the clutch pulling too much current or feeding
back electrical noise that interfered with the ignition or computer
circuit. But your right, that does sound like a mighty long stretch. :/

Anyhoo, glad your Jeep is back and running.

--
DougW

Re: Liberty - Misfire
 

Bruce Yelen did pass the time by typing:
> Some time ago, I posted to this group about a chronic problem with my 2003
> Liberty - giving P300 codes (misfire in multiple cylinders). We finally
> noticed a pattern that it only occured when the AC was running. The dealer
> started running their analyzer with the AC compressor running, and not
> running, and found a substantial difference that did not appear with other
> vehicles. Noticing that the compressors on the new Libertys on the lot were
> at least 4 EC levels later (this from the part number), they decided to swap
> out the compressor. What was unusual, is that the Denver Mopar depot was
> over 50 compressors back-ordered! Rather than making me wait, the dealer
> pulled a compressor from a new vehicle on their lot. The misfire problem
> has not occured since.
>
> Does this make sense to anybody? Also, has anybody heard any problems with
> the compressors? I'm told that Denver is almost never back-ordered on this
> part.

Sense... sorta...

Could have been due to the clutch pulling too much current or feeding
back electrical noise that interfered with the ignition or computer
circuit. But your right, that does sound like a mighty long stretch. :/

Anyhoo, glad your Jeep is back and running.

--
DougW

Re: Liberty - Misfire
 

In message <UXB%c.6808$OZ6.955@okepread06>, "DougW" wrote:

>Bruce Yelen did pass the time by typing:
>> Some time ago, I posted to this group about a chronic problem with my 2003
>> Liberty - giving P300 codes (misfire in multiple cylinders). We finally
>> noticed a pattern that it only occured when the AC was running. The dealer
>> started running their analyzer with the AC compressor running, and not
>> running, and found a substantial difference that did not appear with other
>> vehicles. Noticing that the compressors on the new Libertys on the lot were
>> at least 4 EC levels later (this from the part number), they decided to swap
>> out the compressor. What was unusual, is that the Denver Mopar depot was
>> over 50 compressors back-ordered! Rather than making me wait, the dealer
>> pulled a compressor from a new vehicle on their lot. The misfire problem
>> has not occured since.
>>
>> Does this make sense to anybody? Also, has anybody heard any problems with
>> the compressors? I'm told that Denver is almost never back-ordered on this
>> part.
>
>Sense... sorta...
>
>Could have been due to the clutch pulling too much current or feeding
>back electrical noise that interfered with the ignition or computer
>circuit. But your right, that does sound like a mighty long stretch. :/
>
>Anyhoo, glad your Jeep is back and running.

Anything that causes the PCM to detect crankshaft speed fluctuations outside
normal parameters can cause it to trigger a misfire DTC. Loose, slipping,
vibrating accessory belts, etc. Maybe a slipping/chattering A/C clutch?
Compressor with an internal problem? Lots of possibilities when talking misfire
faults. Fortunately, it's usually a misfire. :-)

Re: Liberty - Misfire
 

In message <UXB%c.6808$OZ6.955@okepread06>, "DougW" wrote:

>Bruce Yelen did pass the time by typing:
>> Some time ago, I posted to this group about a chronic problem with my 2003
>> Liberty - giving P300 codes (misfire in multiple cylinders). We finally
>> noticed a pattern that it only occured when the AC was running. The dealer
>> started running their analyzer with the AC compressor running, and not
>> running, and found a substantial difference that did not appear with other
>> vehicles. Noticing that the compressors on the new Libertys on the lot were
>> at least 4 EC levels later (this from the part number), they decided to swap
>> out the compressor. What was unusual, is that the Denver Mopar depot was
>> over 50 compressors back-ordered! Rather than making me wait, the dealer
>> pulled a compressor from a new vehicle on their lot. The misfire problem
>> has not occured since.
>>
>> Does this make sense to anybody? Also, has anybody heard any problems with
>> the compressors? I'm told that Denver is almost never back-ordered on this
>> part.
>
>Sense... sorta...
>
>Could have been due to the clutch pulling too much current or feeding
>back electrical noise that interfered with the ignition or computer
>circuit. But your right, that does sound like a mighty long stretch. :/
>
>Anyhoo, glad your Jeep is back and running.

Anything that causes the PCM to detect crankshaft speed fluctuations outside
normal parameters can cause it to trigger a misfire DTC. Loose, slipping,
vibrating accessory belts, etc. Maybe a slipping/chattering A/C clutch?
Compressor with an internal problem? Lots of possibilities when talking misfire
faults. Fortunately, it's usually a misfire. :-)

Re: Liberty - Misfire
 

In message <UXB%c.6808$OZ6.955@okepread06>, "DougW" wrote:

>Bruce Yelen did pass the time by typing:
>> Some time ago, I posted to this group about a chronic problem with my 2003
>> Liberty - giving P300 codes (misfire in multiple cylinders). We finally
>> noticed a pattern that it only occured when the AC was running. The dealer
>> started running their analyzer with the AC compressor running, and not
>> running, and found a substantial difference that did not appear with other
>> vehicles. Noticing that the compressors on the new Libertys on the lot were
>> at least 4 EC levels later (this from the part number), they decided to swap
>> out the compressor. What was unusual, is that the Denver Mopar depot was
>> over 50 compressors back-ordered! Rather than making me wait, the dealer
>> pulled a compressor from a new vehicle on their lot. The misfire problem
>> has not occured since.
>>
>> Does this make sense to anybody? Also, has anybody heard any problems with
>> the compressors? I'm told that Denver is almost never back-ordered on this
>> part.
>
>Sense... sorta...
>
>Could have been due to the clutch pulling too much current or feeding
>back electrical noise that interfered with the ignition or computer
>circuit. But your right, that does sound like a mighty long stretch. :/
>
>Anyhoo, glad your Jeep is back and running.

Anything that causes the PCM to detect crankshaft speed fluctuations outside
normal parameters can cause it to trigger a misfire DTC. Loose, slipping,
vibrating accessory belts, etc. Maybe a slipping/chattering A/C clutch?
Compressor with an internal problem? Lots of possibilities when talking misfire
faults. Fortunately, it's usually a misfire. :-)