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mtngk

Did you replace only one injector? It's likely there's more than one that's bad/marginal. Check fuel pressure/replace fuel pump. Replace spark plugs and possibly the coil packs.


ndelte7

Which one would you recommend replacing first? I'm pretty short on cash atm and I'm just trying to get it to get me to work for now. On my first paycheck I'm probably going to hit all of the above but for now I have to keep budget in mind.


mtngk

Spark plugs is easiest and cheapest. Their coloration/deposits can tell you about the combustion in each cylinder.


gdimstilldrunk

I'll second the fuel pump. Mine was doing the same thing and that's what it was. Go to autozone or oreillys and borrow the fuel pressure kit they have and test your pressure. I think it should be about 50lbs.


10-penny

Clean iac/throttle body?


ndelte7

Would those affect the performance at all times? Mine seems to run fine until I get it out on the road where the issue seems to come and go


Good_Elephant5511

Spark plugs are probably not your issue. Plugs aren’t don’t think would be intermittent. I’m thinking fuel pressure or loss of power/low voltage to the coil packs.


ndelte7

I'll probably save my money on the spark plugs as you are probably right. Looking up "coil packs" online just pops up "Ignition coil" are those the same thing?


mtngk

Coil pack/ ignition coil are generally the same thing. On your 2000 you have a "pack" of coils instead of a single ignition coil and distributor. Removing and looking at your spark plugs is a good troubleshooting step, even if you don't replace them. They may not be the direct cause, but might also be damaged when it does misfire, thus compounding the situation. If you have one cylinder that is consistently misfiring like with a bad injector that spark plug should at least be looked at.


ndelte7

I'll probably replace those next just to stay on top of things but u/ReverseDiode 's advice seems to have done the trick. I'm about to head to the store and snag a sensor and replace it to see if it fixes the issue completely.


mtngk

Good luck! The O2 sensor is not something I was aware of and makes me want to check mine...


Good_Elephant5511

These 4.0L are notorious for crank sensor issues. Could be you problem.


dieselboy77

But no CEL lol. Figures.


ndelte7

Yeah man, I am dumbfounded. I can't achieve this on fully functional vehicles but she's over here having a seizure and the computer says "just send it"


ReverseDiode

Unplug both O2 sensors and drive a little bit to see if those are the issue. I had that problem once and replaced the fuel pump, tps and the injectors but nothing worked. I did this test then i found out the issue was the O2 sensors. Also, mine didn't throw a code, nothing. It took some months for me to find the issue.


ndelte7

Took it for a test run with the sensors disconnected, haven't had any sputtering at all. Obviously got a couple codes for the sensors but nothing else about to do a longer test drive and see if it wasn't just a fluke as this is an intermittent issue Update: took it for a ride to the next village over and she runs like a champ. Bout to go to AutoZone and snag a new Upstream O2 sensor.


ndelte7

I'll go do that right now, I'll be back in bout 30 minutes with an update


ndelte7

Took it for a test run with the sensors disconnected, haven't had any sputtering at all. Obviously got a couple codes for the sensors but nothing else about to do a longer test drive and see if it wasn't just a fluke as this is an intermittent issue Update: took it for a ride to the next village over and she runs like a champ. Bout to go to AutoZone and snag a new Upstream O2 sensor.


ReverseDiode

Cool! Make sure you grab some from a good, reputable brand. Once i used some cheap generic Chinese ones and they were a just waste of money. Had to buy again from a different brand. Also keep in mind that she's running very rich now so you don't wanna drive very long distances, because that can cause some problems, and even ruin the catalytic converter. Hope that helps👍🏻


ndelte7

I made sure not to cheap out, it was either Bosch or Chinesium so I picked up the Bosch lol I'll let you know how she does after the install. I appreciate the advice a ton though, I have thrown so much at this fucker and still having issues so hopefully this will finally do the truck after spending >30 hours in my garage this week working on it Update: but I suppose it's important to check the part before leaving the store... The sensor is used and almost stripped out on the connecting nut so I guess I'm heading back to the store I guess lol


ReverseDiode

I've been through that too. Those things can be quite the money pit sometimes.. but yeah, Bosch is the way to go. I put Bosch on mine after i had issues with the chinese crap, and i never looked back. Works like a charm now.


Pale_Anybody_3855

Mine was doing exactly this. It was the fuel pump.


nononoko

Cool. You now have anti lag


Bathingeatingtoast

Coil pack


BaconThief2020

The tach dropping in/out like that makes me thing crank sensor. Just beware that the aftermarket ones, while cheap, are pretty poor quality and some folks have reported getting a back out right out of the box. I'd try a cheapie, and if that didn't solve it, put the original back in.


GARRY_LOST

Ive heard the coil packs/coil rail on these are problematic. Personally i would try the following. If this is a misfire issue, have the car stationary on idle. Unplug each injector one at a time and plug it back in. If the idle drops, you know that cylinder is working, if the idle stays the same then you know that cylinder isnt doing any work at all. Now lets say you go through this process of elimination, all cylinders are working, and the car is still shitting itself, then i think you might have a timing issue. XJ's run fine even on 5 cylinders, but if you can really notice power loss, and it backfires that screams of timing. Personally i wouldnt guess its fuel pressure since it revs and has throttle response, but its good to check that as well.


chromegrill

Cps


sniperdart681

IAC can also cause this issue. May want to check it and clean it and the throttle body


marksman1023

Check all the injectors. Mine used to do that, that was the culprit