Running Rough / Rough Idle (1 Viewer)

[jso5000]

Here's the story:
A week ago the wife and I are out running errands in the LC. Running real nice no issues.
We go to Starbucks to get a coffee and while in line the engine starts missing. Started with a single miss then got progressively worse. Drove it home and it ran terribly all the way.
Next day start up the LC and same thing, running rough and rough idle.
Had to go out of town for 3 days, so had wife take the LC over to the dealership to diagnose.
Dealer came back with: It needs a major tune up. Plugs, cap, rotor, coil, fuel filter, air cleaner, pcv valve, valve cover gasket and associated gaskets and plug wires. ($1300+ estimate)
I told them to do the fuel filter and I would take care of the rest.
So today I put in plugs (NGKs), a distributor and rotor and cleaned the throttle body. Fired it up and it ided and ran smooth. The idle was high 1100 rpm but it was smooth. Took it out for a drive - no problems no misses. Just when I thought it was fixed (at least until other parts arrive) it was just idling in the driveway...it misses. Then it get progressively worse just as before. Now Im back to idling and running rough. Any thoughts? Is this symptomatic of a pcv valve failure?
Any and all help is welcome.

 

[maddss]

What year ? Any Engine Codes ? Probably not the PVC.

94 LC, I have similar issues (2).
1. LC starts fine. When the engine is cold or hot, the engine just stumbles, feels like its a fuel problem. Push on the pedal and rpm's do not change. Eventually clears up.

2. LC at running temp, for no reason it just shuts off. Wait 30 secs and starts no problem.

Both problems occur then are gone for several days/weeks.

Items replaced, Plugs, wires, cap, rotor. To be replaced fuel filter sock and fuel filter. Air/oil separator installed and cleared high idle. Currently now have CEL 71.

 

[parker019]

Madss , Jso5000 - what ended up being the cause of this problem ?

 

[maddss]

Madss , Jso5000 - what ended up being the cause of this problem ?

My problem was a bad #6 fuel injector

Rough idle mis fire

94 LC 225k. Has a rough idle, runs rough and has a stumble as you drive. I installed new NGK wires, Denso plugs and factory cap and rotor. Also clean the throttlebody. Still have the same rough idle and stumbling. One at a time I removed each spark plug boot to determine which cylinder...

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