I can try it. I’ve got nothing to lose at this point. The guy I bought it from said he changed out the injectors when he was chasing the same problem so the injectors are fairly new but you never know.
Cylinder misfire help
- Thread starter The white hammer
- Start date
Yeah. It's not a popular test for our tj's for whatever reason, but an injector balance test is probably in order. You'll need a fuel gauge and a tester like this.
https://www.amazon.com/dp/B01CNOR84Q/?tag=wranglerorg-20
I know you said you replaced the spark plugs but you may have cracked an insulator on number four when you did it I would double check the spark plugs just to make sure
Also, not sure if this info helps but it’s a 97 and it’s sat far more than it’s been driven. It was an old man’s. He used it on his ranch. I bought it after he passed. It sat much more than it was driven. A 97 model with only 43k miles
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Nobody has mentioned checking for a cracked exhaust manifold. My 97 misfired all the time because it was running rich until I removed the cracked manifold and replaced it.
What kind of has mileage are you getting?
I was getting 10 to 12 cracked...up to 14 sometimes 15 fixed with Banks headers.
-Mac
What kind of has mileage are you getting?
I was getting 10 to 12 cracked...up to 14 sometimes 15 fixed with Banks headers.
-Mac
Man I’m not exactly sure about the mileage but I know it’s horrible. I’ll go through a quarter tank making a 30 minute drive. I did notice my exhaust smells strong. Like gas I just figured part of the bad gas mileage was because it’s lifted with 35x14 R15 swampers but yes, I definitely feel like it runs rich and sucks down that gas. Would a cracked manifold be something you could visually check?
That sounds like a bad upstream O2 sensor. If you install one make sure to ONLY install an NTK or NGK brand. No store brands or Bosch O2 sensors!
I’ve already replaced BOTH sensors with NGK. About a month ago. I guess I could try it again? Is there a way to confirm the sensor is working?
Yes! Mine looked like a tiny hairline crack and turned into this when removed...
Ok I checked the exhaust header. Nothing that I can see them I confirmed with the guy I bought it from that it’s a brand new stainless header. Not even a year old.
Do you guys think that since the jeep sat more than it ran that I could have a lifter going out?
There is a TSB lurking out there around carboned exhaust valves causing misfires. I want to say root cause was low rpm usage.
Here is a link to a post that I found.
https://www.wranglerforum.com/threads/service-bulletin-for-multi-cyl-misfire.109037/
Here is a link to a post that I found.
https://www.wranglerforum.com/threads/service-bulletin-for-multi-cyl-misfire.109037/
Going back to your original post, and verifying a few items:
1. Your fuel pressure was good, what was it? Did it drop or fluctuate at all?
2. When you checked compression, did you get the values for all cylinders cranking it the same amount of time, or did it take #4 significantly more cranks to get to the pressure you measured?
3. Looks like this issue was chassed down by the previous owner and might have contributed to why they sold it, be cautious about assuming what was done prior to you was done correctly.
4. Might be a good idea to get an OBDII tool with live logging so you can poke around and see what stands out.
1. Your fuel pressure was good, what was it? Did it drop or fluctuate at all?
2. When you checked compression, did you get the values for all cylinders cranking it the same amount of time, or did it take #4 significantly more cranks to get to the pressure you measured?
3. Looks like this issue was chassed down by the previous owner and might have contributed to why they sold it, be cautious about assuming what was done prior to you was done correctly.
4. Might be a good idea to get an OBDII tool with live logging so you can poke around and see what stands out.
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