2004 jeep liberty missfire

[Seth007]

During acceleration engine stalls, I hooked up a code reader and pulled codes P0305, P2314. I took it to a friends shop he said prob. a bad pcm/tcm I installed a new one still the same problem. Ive put in new plugs, new coil. Any Ideas? By the way it is a 3.7 v-6. Any help would be greatly appreciated.

[dagwan11]

I would see what is common between the codes first. Isn't a PCM kinda pricey?

SYMPTOM
P0305-CYLINDER NO.5 MISFIRE

TEST NOTE
This symptom is diagnosed using the test P0300-MULTIPLE CYLINDER MISFIRE.

WHEN MONITORED
Any time the engine is running, and the adaptive numerator has been successfully updated.

SET CONDITION
When more than a 2% (2.5% LEV) misfire rate is measured during two trips, or with a 10% to 30% misfire rate during one trip.

POSSIBLE CAUSES

* Intermittent misfire
* Visual inspection
* (A142), (F142) ASD relay output circuit
* Engine mechanical problem
* Ignition coil
* Coil control circuit
* Spark plug
* Checking fuel pressure
* Fuel pump inlet strainer plugged
* Restricted fuel supply line
* Fuel pump module
* Checking fuel leak down
* Fuel injector
* Injector control circuit
* PCM

SYMPTOM
P2314-IGNITION COIL NO.5 SECONDARY CIRCUIT- INSUFFICIENT IONIZATION (3.7L)

TEST NOTE
This symptom is diagnosed using the test P2302-IGNITION COIL NO.1 SECONDARY CIRCUIT- INSUFFICIENT IONIZATION (3.7L).

WHEN MONITORED
Engine running and battery voltage greater than 10 volts .

SET CONDITION
If PCM detects that the secondary ignition burn time is incorrect, to short, or not present, an error is detected. One Trip Fault. Three good trips to turn off the MIL.

POSSIBLE CAUSES

* Good trip equal to zero
* (A142) ASD relay output circuit open
* Capacitor(s) shorted to ground
* (A142) ASD relay output circuit shorted to ground
* Coil on plug resistance
* Ignition coil
* Coil control circuit open
* Coil control circuit shorted to ground
* PCM

[discnik]

Have you tried a compression test of that cylinder ? There is a problem with the valves on those engines. Hope this helps.

[Seth007]

I ordered the pcm online it was $300, Im sending it back today for refund. My first instinct was clogged fuel filter, but I believe in repair manual it states that the filter is a lifetime part not to be changed and I think you have to drop the gas tank. I probally should get a pressure test. If it was the fuel was restricted in some way wouldnt I get an error code on other cylinders?

[Seth007]

Is a compression test I can do myself? I also am going to change valve cover gasket for that side when I have the valve cover off is there a way of visual checking the valve?

[Seth007]

Just an update I swapped 3 and 5 coils to verify a bad coil sure enough after driving it shot a #3 missfire. I replaced the coil and idle is much better and no more hesitation during acceleration, looks like problem solved! Thanks for all the help.

[dagwan11]

Glad to see you got it fixed.