Not running on 4 cylinders . changed coil pack injectors new leads unplug tps sounds a little bit better plug back in an runs very rough

Check Engine Light/Misfire Due to Intake Valve Locks ...

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Jeep Liberty Check Engine Light/Misfire Due to Intake Valve Locks/Valves. ...Misfire cyc 4 and random cyc misfires, changed coil packs and plugs... sounds as if rod ... Light came on again (misfire on cylinder 4) - switched coil from 4 to 2. Light ...

Jeep Liberty Questions - Cylinder Misfire code - CarGurus

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CarGurusMay 27, 2009 - #4 misfire new plugs and coil pack on #4 light came back on after 300 miles if ... How come it stopped misfiring for 2-3 months, and now is back? ... I have a 2005 Jeep Liberty 6 cylinder, engine light came on scaned the codes ...

Liberty Cylinder Misfire / Computer issue? - JeepForum.com

Cold starting misfires can often be caused by either tired high tension spark plug leads or ignition coil packs. If replacing leads, then replace with a full, new set. Coils can be changed individually, but it is often the case that if one has failed, then the others aren't far behind. Some cars have individual coil packs on each spark plug. Some cars have a single pack for all plugs and some have coil packs which may control two or more plugs.

To check for a misfire (ignition failure) follow these steps:

(Cold start) (Use a pair of insulated pliers)

1) Start the vehicle

2) When the vehicle starts misfiring, disconnect plug leads or coil pack connections one at a time. If the vehicle idles even more roughly, then that plug or pack should be considered fine.
Replug each connection before disconnecting the next one. Once you disconnect a plug lead or coil pack connection and find no difference in poor engine running, then you have likely found the offending cylinder. Check the spark plug condition, lead and/or coil condition and connections on that cylinder.

3) Replace components as necessary.

Sounds like a dead coil pack and needs replaced cause you're getting no fire to those plugs and causing a rough idle. Another thing is, that catalytic converter will only turn red because it's plugged up and needs replaced. Have that checked out friend.

What did the spark plugs look like when you took them out of cylinders 4 & 5 that you say are not running. If they are wet and black and smell like gas, I would guess you have back spark plug wires going to those cylinders. If they looked about the same as the other cylinders, or a tannish color and dry, then I would guess injectors.

Make sure the HT leads are secure. They might be popping off, causing it to not fire on one cylinder. I always change the plugs and leads at the same time to keep them the same age. HT leads break down rapidly and need regular replacement.

Replace the coil for number 3 cylinder.

remove the coil pack and look at bottom of it if it shows any cracks coil is bad very common on these vans if you have a noid light check for injector pulse on #4 if you have pulse and good blue spark most likely the injector is bad you have to remove upper plenum to get injectors out let me know how you make out

Replace your #5 cylinder fuel injector. You rough idle sounds like low, or no fuel to the cylinder. Your hesitation on accelleration says the same.. A new fuel injector should resolve your issue.

I hope this helps you, and I wish you luck on your repair.

Try checking the spark plug, and the spark wires, if that doesnt clear things up then try replacing the roter under the distributor cap and check the cap for any corrosen

The cylinders are numbered as on the spark pack you changed. You might have done better putting the seafoam in the tank as an injector cleaner. Not sure why you changed so many parts, you seem to know how to get the codes from test connector lead hookup and the blink pattern. You might also want to check the fuel rail pressure and the crank and cam angle sensors. Before replacing the injector, swap the #4 injector with the adjacent one and see it the code moves with the injector or stays put. If the code stays on #4, then check the injector wiring, if it moves clean or replace the injector.