2003 Liberty 2.4L Stalling after recent work done

[Armstrong001]

I have a 2003 Liberty 2.4L with about 180k miles on it. I recently started experiencing rough starting, having to crank the engine over for extended periods of time before it would catch. I replaced the spark plugs and installed a new ignition coil. That didn't seem to solve the problem. I then replaced the crankshaft position sensor. Now, it wants to stall out if no gas is applied on startup. If I get it running, it will idle around 1000/1500 rpm, but then if I accelerate and let off the gas, it will die again. No check engine lights come on. Reading some other threads, maybe it's the Intake Air Control? Camshaft position sensor? Do those go bad and NOT have a code?

 

[sleazy rider]

“A” new ignition coil? There’s six of them that should be changed as a set. Did you use the recommended NGK copper spark plugs?

 

[duderz7]

“A” new ignition coil? There’s six of them that should be changed as a set. Did you use the recommended NGK copper spark plugs?

4 coils in his case. It's my understanding that ignition coils can be tested with a multi meter. They generally work or not. Inspect the coil boots carefully for tears. Also use only mopar sensors. Perhaps a bottle of fuel injector cleaner will help. Did you replace a coil due to misfire? Try moving it to see if misfire follows, then plug if no change.

 

[LibertyTC]

See also this thread re the 2.4- 4 cylinder
https://www.jeepkj.com/threads/2-4-liter-engine-stalling-and-misfiring.72083/

 

[Armstrong001]

Yes, one coil. The 2.4L motor has a box that sits on top distributing spark to each plug, not individual coils sitting on each cylinder.

I have added fuel injector cleaner early on when it was hard starting and then i started getting a check engine light and it got rid of the check engine light code but still wouldnt start well. No light has come back on, but now it is stalling.

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[Ksat]

Perhaps you have a vacuum leak of some sort causing the problem. Could be in the EVAP system.

I would scan for codes and also check live data and fuel trims while I was in there, too.

 

[Armstrong001]

Took it to a mechanic. They ran a compression test and #2 cylinder is only at 50 psi. At 180k miles, they said the engine is probably jist worn out, and that they could tear it down to fix whatever is causing the low compression but that it wouldn't guarantee other parts wouldn't wear out soon, or that it could even be fixed. It's drivable for now. Need to figure out how we want to go forward.

 

[sleazy rider]

They only did half the diagnostics. A leakdown test would have isolated the issue as to whether valves or rings were bad. Rings are full rebuild, head is much easier.

 

[duderz7]

You could look around for a decent kj with a 6cyl, swap your diffs over and be miles ahead of half of us in proper upgrades.

 

[Ksat]

As stated, a leak down test should be performed to narrow down the cause. The problem could be something relatively simple. The shop should have known this already instead of jumping right to the tear-down idea.