Needed maintenance

VallenMaes

VallenMaes

TJ Enthusiast
Joined
May 15, 2017
Messages
259
Location
Omaha, NE, United States
So ive got a killer missfire. Ive been chasing a less serious random missfire but couldnt figure out the cause. Yesterday night i went to drive home and it was so bad i couldnt accelerate out of my parking spot. Luckily i had my previous spark plugs in my tool box(just hadnt thrown them away yet), so i was able to throw those in and get home. My question is...

1) How do i tell my lady that i need to get quality parts so this doesnt happen again.

2) What all should i get. I still have the random missfire

All help is appreciated. OH! i also have a lifter tic now and it doesnt go away when accelerating. The tic as well as the missfiring just goes up with the rpm. Its annoying as all get out. Im about 2000 miles into my oil change but its full synth so if i dont have to change oil that'd be nice.
 
VallenMaes said:
So ive got a killer missfire. Ive been chasing a less serious random missfire but couldnt figure out the cause. Yesterday night i went to drive home and it was so bad i couldnt accelerate out of my parking spot. Luckily i had my previous spark plugs in my tool box(just hadnt thrown them away yet), so i was able to throw those in and get home. My question is...

1) How do i tell my lady that i need to get quality parts so this doesnt happen again.

2) What all should i get. I still have the random missfire

All help is appreciated. OH! i also have a lifter tic now and it doesnt go away when accelerating. The tic as well as the missfiring just goes up with the rpm. Its annoying as all get out. Im about 2000 miles into my oil change but its full synth so if i dont have to change oil that'd be nice.
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We need way more man. Are you 100% sure its a misfire? I ask so we don’t troubleshoot the wrong thing. It it is, a code will be thrown. Go to Advanced and have them print you the code. These engines really like certain spark plugs, a member of this forum generously provided a write-up and reccomendation for spark plugs.

https://wranglertjforum.com/threads/what-are-the-best-spark-plugs-for-my-jeep-wrangler-tj-4-0.4196/
 
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VallenMaes said:
p0300 sorry should have put that in there.
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Ok the common theme with p0300 centers around spark plugs, air intake leak, ignition coil, fuel injectors, sensors ect.

I would usually reccomend checking your intake with this kind of code, but if changing your spark plugs did it, I’d start there.

Any other symptoms/issues other than the misfire?
 
So it started life as a cylinder three misfire p0303 i replace the spark plugs with some generics, and it was fine for like two days. ended up getting some champion and that was good for about a month. then got the random misfire code. Havent had the money to take care of anything but i should now.
 
VallenMaes said:
So i stated life as a cylinder three misfire p0303 i replace the spark plugs with some generics, and it was fine for like two days. ended up getting some champion and that was good for about a month. then got the random misfire code. Havent had the money to take care of anything but i should now.
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Any random misfire codes I have encountered in the past have been related to intake. I’d start there, as its cheap to locate! :)
 
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Just ordered up a filter. Going to check and see if i can find a leak anywhere. Ordered champion double platinum plugs. Going to start looking for an intake system in the event i do have a leak.
 
VallenMaes said:
Going to start looking for an intake system in the event i do have a leak.
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Are we referring to an air intake system? If so, get the stock one. The aftermarket cold air intakes have been proven time-and-time again to be nothing but a complete waste of money, and potentially damaging to your engine via their sub-par K&N (or K&N style) air filters.

I may have misunderstood, in which case I apologize if I did!
 
VallenMaes said:
Just ordered up a filter. Going to check and see if i can find a leak anywhere. Ordered champion double platinum plugs. Going to start looking for an intake system in the event i do have a leak.
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So unless your filter is bad you shouldn’t need a new one. Just to clarify, you want to clear the intake manifold and gasket. Use carb cleaner and see if the revs spike when you spray it around the gasket/manifold. If it does you have a leak. You should not have to replace the whole system, judt whatever component is bad (more than likely if it is a leak, its the intake gasket).
 
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VallenMaes said:
@JamesAndTheSahara Awesome. will do. I dont "need a filter" but i have no idea the brand thats in it. im trying to pick up after the PO still. I just wanted the piece of mind.
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Nothing wrong with that :).

Just trying to make sure if its not the intake, you may money to get to the root of the problem. Ask me how I know these things can get expensive :D.
 
I'm a little concerned with the "lifter tick" that you mentioned earlier.

Check all of your manifold bolts. See if any of them are broken. A manifold leak sounds like a lifter tick, and if it gets serious enough it will start to cause misfires. I'd start there.
 
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VallenMaes said:
@StG58 And thats what i keep hearing when i was researching. Ill check them again but they all seemed fine. The thing that doesnt add up with that though is i got the tick after last night really rough firing.
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Busted bolts are not a for sure thing, but a manifold leak someplace is what comes to mind for me. Physically put a wrench on each bolt and nut and give it a tug. Check the exhaust manifold for cracks. Look the exhaust connections over as well.

A sudden lifter tick after severe misfire could also be a bent push rod or a lifter stud pulled from the head. I've never heard of that happening with a TJ though.

It really sounds like a fuel mixture problem caused your misfires, and that caused a more severe intake and / or exhaust leak. Intake leak = misfire Lifter tick sound = exhaust leak The only thing common to the intake system and the exhaust system is the gasket and bolts. Check for vacuum connection leaks as well.

On the bright side, it doesn't cost anything to check those out other than time.
 
@StG58 Aslo what do you think cause the fuel mixture to be off? I dont have any codes except this one and not heating up fast enough. ill be getting a new thermostat as well. (should be 195 right?)
 
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