Misfire count

[Brahmajoe]

While at idle I have 0 misfires according to JScan. While driving I have some at all cylinders but #2 had over 20 and #3 had over 40 the rest where under 15. Is this a normal count?

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[jebiruph]

Here's a link that's shows misfires count for a 30 min drive on a good running engine. https://www.jeepgladiatorforum.com/forum/threads/live-data-monitoring-with-jscan.55262/post-913398

 

[ShadowsPapa]

While at idle I have 0 misfires according to JScan. While driving I have some at all cylinders but #2 had over 20 and #3 had over 40 the rest where under 15. Is this a normal count?

Some of the answer will depend on the time driven, RPM, driving conditions and so on. You may have more under load, against the wind, up hills, accelerating and so on, and fewer with no load.

Like already posted - some are normal - what's normal or not depends on how long did it take to get to those numbers?

 

[Brahmajoe]

Some of the answer will depend on the time driven, RPM, driving conditions and so on. You may have more under load, against the wind, up hills, accelerating and so on, and fewer with no load.

Like already posted - some are normal - what's normal or not depends on how long did it take to get to those numbers?

It was a 20 min highway ride

 

[Hootbro]

While at idle I have 0 misfires according to JScan. While driving I have some at all cylinders but #2 had over 20 and #3 had over 40 the rest where under 15. Is this a normal count?

I have roughly the same numbers on my daily commute. You will probably find that one or two cylinders will be the same majority recording of misfire events with other having none or almost none. It will also vary between each engine measured.

The misfire counter and whether it posts a pending or posting CEL for misfire code, will depend on the number of events in a given time period rather than over long time period with spaced out misfire events.

Also to keep in mind, the misfire count the PCM records is actually a guesstimate the PCM "thinks" a misfire occurred factoring in the various engine parameters. A high total count will have more false misfire counts over a longer drive cycle event than one with a short drive cycle.

The main thing to watch with Jscan and the misfire count is to monitor it during first cold start. That will give you an indication what if any specific cylinders will be suspect later down the road. Generally, if at cold start the misfire counter stays below around roughly 50 or or less before it comes off high idle at start, it will not post any pending codes. In the 50-75 range, it will post a pending misfire code with the only indication to you of the ESS being disable but no check engine light. Above the roughly 75 count range at cold start, it will then post a hard CEL with a misfire code. Monitoring startup misfire counts on a relative up to temp hot engine will generally show very little counts vs. cold.

The above numbers I mentioned are not gospel and just a rough estimate I dealt with when I had my 2020 Gladiator that had the occasional ESS disable message on cold start and my monitoring with Jscan trying to troubleshoot the misfires I had for it. With my 2021 Gladiator, I have had no issue with misfires tripping the ESS disable or posting any misfire codes with my misfire count on startup and over my daily commute drive matching somewhat close to what you have and not giving me any concern.

 

[Brahmajoe]

I have roughly the same numbers on my daily commute. You will probably find that one or two cylinders will be the same majority recording of misfire events with other having none or almost none. It will also vary between each engine measured.

The misfire counter and whether it posts a pending or posting CEL for misfire code, will depending on the number of events in a given time period rather than over long time period with spaced out misfire events.

Also to keep in mind, the misfire count the PCM records is actually a guesstimate the PCM "thinks" a misfire occurred factoring in the various engine parameters. A high total count will have more false misfire counts over a longer drive cycle event than one with a short drive cycle.

The main thing to watch with Jscan and the misfire count is to monitor it during first cold start. That will give you an indication what if any specific cylinders will be suspect later down the road. Generally, if at cold start the misfire counter stays below around roughly 50 or or less before it comes off high idle at start, it will not post any pending codes. In the 50-75 range, it will post a pending misfire code with the only indication to you of the ESS being disable but no check engine light. Above the roughly 75 count range at cold start, it will then post a hard CEL with a misfire code. Monitoring startup misfire counts on a relative up to temp hot engine will generally show very little counts vs. cold.

The above numbers I mentioned are not gospel and just a rough estimate I dealt with when I had my 2020 Gladiator that had the occasional ESS disable message on cold start and my monitoring with Jscan trying to troubleshoot the misfires I had for it. With my 2021 Gladiator, I have had no issue with misfires tripping the ESS disable or posting any misfire codes with my misfire count on startup and over my daily commute drive matching somewhat close to what you have and not giving me any concern.

Thanks ? I performed this because I have a small vibration at idle usually cold starts or after sitting for a few hours. No codes and my ess still operates. Just annoying. I checked plug 1 just to see if anything was fouled. I had a 6 quart oil change by dealer prior. Everything looked good, plug, cylinder and boot

 

[Hootbro]

Thanks ? I performed this because I have a small vibration at idle usually cold starts or after sitting for a few hours. No codes and my ess still operates. Just annoying. I checked plug 1 just to see if anything was fouled. I had a 6 quart oil change by dealer prior. Everything looked good, plug, cylinder and boot

Have you tried monitoring a cold start in real time to see what cylinder count rises the quickest?

On my 2020, I had a #4 cylinder that would usually go from 0 to 30 range within the first 30 seconds after start and when the engine fuel trim would start to come back off the high idle. Other cylinders would either be 0 or single digits at best for a count. I occasionally would have a rough start idle with Jscan misfire monitoring with the numbers I mentioned in my previous post.

There is numerous other threads on misfire issues and the Pentastar with varying causes. I have come to the conclusion if you are not getting any pending misfire codes with ESS being disabled and/or actual posting misfire codes with a CEL, it is pretty much normal operation for these Pentastar's to have the occasional rough cold start idle. One can chase their tail trying to find perfection in this engine when it comes to misfires.

 

[ShadowsPapa]

if you are not getting any pending misfire codes with ESS being disabled

OK, I'll bite - why does ESS keep getting brought up in cases where it has no impact, and can have no impact?
ESS doesn't effect:
cold starts (either remote or direct button presses by the operator)
Hot starts (button presses by the operator)
Running before an ESS event (while you are driving or sitting with foot off the brake)
Running after an ESS restart once it's running and you hit the gas.
Any engine operation until all ESS conditions are met (and that includes your foot being on the brake pedal with the correct amount of pressure and the vehicle being at a full stop, 0mph)
Anyway, ESS doesn't matter so I'm curious as to it being mentioned with any engine operations at all.........


As far as cold starts - it's running in open loop mode off a map or given set of instructions which have to be created for the most common sets of conditions. If like other engines, it's going to run rich at idle when first started.............
Until the O2 sensors heat up, it's flying off that map. Around here, it could be 10 below zero, 100 degrees, extreme humidity (100% with a dew point the same as the actual air temperature), or 25% humidity, high air pressure, low air pressure, and it's got to fire every time based on a table that can only do so much. If it's firing too rich and the mixture doesn't burn, then the next batch likely won't burn well either so it could take a half dozen cycles to clear that cylinder out and get it firing properly.
I've also wondered - what do they count as a technical misfire? A complete absence of burn, or an incomplete burn, or just what? We used to consider a misfire something you heard and felt - but these seem to count misfires you'd never know happened at times.

So my question would be - has anyone done this cold start misfire tracking with any other vehicle to see how they do? How does this compare to any other engine in this same class?

 

[Hootbro]

OK, I'll bite - why does ESS keep getting brought up in cases where it has no impact, and can have no impact?
ESS doesn't effect:
cold starts (either remote or direct button presses by the operator)
Hot starts (button presses by the operator)
Running before an ESS event (while you are driving or sitting with foot off the brake)
Running after an ESS restart once it's running and you hit the gas.
Any engine operation until all ESS conditions are met (and that includes your foot being on the brake pedal with the correct amount of pressure and the vehicle being at a full stop, 0mph)
Anyway, ESS doesn't matter so I'm curious as to it being mentioned with any engine operations at all.........


As far as cold starts - it's running in open loop mode off a map or given set of instructions which have to be created for the most common sets of conditions. If like other engines, it's going to run rich at idle when first started.............
Until the O2 sensors heat up, it's flying off that map. Around here, it could be 10 below zero, 100 degrees, extreme humidity (100% with a dew point the same as the actual air temperature), or 25% humidity, high air pressure, low air pressure, and it's got to fire every time based on a table that can only do so much. If it's firing too rich and the mixture doesn't burn, then the next batch likely won't burn well either so it could take a half dozen cycles to clear that cylinder out and get it firing properly.
I've also wondered - what do they count as a technical misfire? A complete absence of burn, or an incomplete burn, or just what? We used to consider a misfire something you heard and felt - but these seem to count misfires you'd never know happened at times.

So my question would be - has anyone done this cold start misfire tracking with any other vehicle to see how they do? How does this compare to any other engine in this same class?

Everything has to be damn novel with you. We get it, you are smart. Surprised you do not bring in the Periodic Table of Elements into the discussion.

I brought up ESS so the OP would know or to look at possible pending misfire codes if he ever gets the ESS disable message.

 

[Brahmajoe]

Everything has to be damn novel with you. We get it, you are smart. Surprised you do not bring in the Periodic Table of Elements into the discussion.

I brought up ESS so the OP would know or to look at possible pending misfire codes if he ever gets the ESS disable message.

OK, I'll bite - why does ESS keep getting brought up in cases where it has no impact, and can have no impact?
ESS doesn't effect:
cold starts (either remote or direct button presses by the operator)
Hot starts (button presses by the operator)
Running before an ESS event (while you are driving or sitting with foot off the brake)
Running after an ESS restart once it's running and you hit the gas.
Any engine operation until all ESS conditions are met (and that includes your foot being on the brake pedal with the correct amount of pressure and the vehicle being at a full stop, 0mph)
Anyway, ESS doesn't matter so I'm curious as to it being mentioned with any engine operations at all.........


As far as cold starts - it's running in open loop mode off a map or given set of instructions which have to be created for the most common sets of conditions. If like other engines, it's going to run rich at idle when first started.............
Until the O2 sensors heat up, it's flying off that map. Around here, it could be 10 below zero, 100 degrees, extreme humidity (100% with a dew point the same as the actual air temperature), or 25% humidity, high air pressure, low air pressure, and it's got to fire every time based on a table that can only do so much. If it's firing too rich and the mixture doesn't burn, then the next batch likely won't burn well either so it could take a half dozen cycles to clear that cylinder out and get it firing properly.
I've also wondered - what do they count as a technical misfire? A complete absence of burn, or an incomplete burn, or just what? We used to consider a misfire something you heard and felt - but these seem to count misfires you'd never know happened at times.

So my question would be - has anyone done this cold start misfire tracking with any other vehicle to see how they do? How does this compare to any other engine in this same class?

2019 3.6 ram 1500 didn’t have this issue non ess

 

[Brahmajoe]

3.6 ram 1500 didn’t have this issue

I watch robmotive on you tube and his 2021 Mojave has the same issue, it is common and just wonder if it’s the programing or what. I wonder if a flash in the future could remedy this

 

[jwolfejt]

This is why i refuse to run anything less than 93 - on any of these newer high compression engines I run only 93 octaine - you can run 87 however from what i've seen on other cars you will see hire misfire counts and retarded timing, etc. I just run 93 (even though it hurts now) but I have not seen this at all on my end. Are you guys running 93 ?

 

[Brahmajoe]

I run 87. The owners manual says running a higher octane doesn’t improve performance

 

[ShadowsPapa]

This is why i refuse to run anything less than 93 - on any of these newer high compression engines I run only 93 octaine - you can run 87 however from what i've seen on other cars you will see hire misfire counts and retarded timing, etc. I just run 93 (even though it hurts now) but I have not seen this at all on my end. Are you guys running 93 ?

Octane is only about preventing self-ignition (detonation) and nothing else. It doesn't burn better, easier, doesn't have more BTUs or any other feature - it simply resists self-ignition.

I run 87 most of the time - often as I can get it, I run U88 because it's a heck of a lot cheaper around here.

This was mine today. I drove it to take kitty to vet and back then it sat 4 hours. I hooked up jscan, started the truck, and after a couple of seconds #2 and 6 each had 2 misfires.
After 2 minutes idling, I drove up the road a bit over a mile - no more misfires. I stopped and turned a corner and with a heavy foot, took off again. RPM up 3,000-4,000 for a while. Misfires incremented up a bit. Drove it a while longer and this was the results after 10 minutes - 2 minutes idling, took off at 150 degree coolant temp and drove 8 more minutes.

 

[ShadowsPapa]

2019 3.6 ram 1500 didn’t have this issue non ess

Different tunes. ESS doesn't matter. It can't.
It does nothing until conditions are met then it shuts the engine off - and restarts it. 0 impact while running.

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