Engine Stutter/Misfire under 75%

[StingerT303]

I've had the JB4 running flawlessly with upgraded plugs for about 15K miles. LOVE it! recently, I experienced engine misfires with violent stutters under about 75% throttle and check engine light that would appear under acceleration and disappear when no throttle is applied. I did not run the code(s). I Installed all new upgraded plugs properly gapped and the problem is much less pronounced but still exists. Maybe I blew a coil pack as well? I cannot get the issue to throw a check engine code anymore, but it is definitely still there. I bet I could throw a code if I recreate the conditions long enough but was worried about blowing another set of plugs. I am running firmware V12.

On map 0 the problem does not occur. Map 1 the problem exists, Map 2 the problem is most pronounced.

Logs of all three maps attached.

Help!!!

 

[Terry@BMS]

If you swapped the plugs then a coil or a fuel injector. Getting a fault code is the easiest way to diagnose. When it comes up does the JB4 logging stop recording or continue to record?

 

[StingerT303]

Wow. You are VERY responsive. Thank you.

I will run it and see if I can produce a fault code. Will the JB4 read that code or do I need a different code reader? I have no reason to believe that the JB4 stops logging when the fault occurs, because when I was logging it the JB4 still gave me the option to stop the log when I wanted to. The logs I uploaded for map 1 and 2 should have shown a couple of the stutters. They are VERY noticeable when driving.

Forgot to mention only mod on the car is intakes.

 

[Terry@BMS]

Logs aren't that useful in spotting misfires unless there is an over boost or fueling issue, neither of which I see.

 

[StingerT303]

Got it. I will try to get a code thrown and report back.

 

[stargtsi]

Im running into the same issue as you. Been trouble free for about same mileage. Was using the Denso plugs gapped at .24
I just got my 2 step colder denso plugs yesterday. Going to gap them to Terry's recommendation of .20 and hope for the best

 

[StingerT303]

Still experiencing this issue. With map 0 there are no problems. Map 1 the problem is noticeable. Map 2 the car jerks pretty violently, but continues to not throw a code. Not sure what to do to diagnose this further. Was hoping to throw a code showing me what cylinder to hone in on or if it was a coil or fuel injector.

 

[stargtsi]

Mine went away after changing my plugs to the 2 step colder ones. You likely have a bad coil pack.

 

[GTA Jay]

Had this same issue. Went it the 2 step colder plugs and gapped at .20 and all seems well.

 

[Terry@BMS]

Still experiencing this issue. With map 0 there are no problems. Map 1 the problem is noticeable. Map 2 the car jerks pretty violently, but continues to not throw a code. Not sure what to do to diagnose this further. Was hoping to throw a code showing me what cylinder to hone in on or if it was a coil or fuel injector.

Try new plugs first.. Those are usually the culprit.

 

[StingerT303]

Yeah the plugs are new Denso 5346 from the Burger site. Thinking its a coil pack but don't really want to spend $65 * 6 to replace them all.

 

[Terry@BMS]

Option B is we can send a 2580 with the JB4's current protection disabled. Seems our protection is more sensitive than the factory so when a plug or coil starts to fail the JB4 system picks up on it before you get major misfire codes.

 

[GregV]

Still experiencing this issue. With map 0 there are no problems. Map 1 the problem is noticeable. Map 2 the car jerks pretty violently, but continues to not throw a code. Not sure what to do to diagnose this further. Was hoping to throw a code showing me what cylinder to hone in on or if it was a coil or fuel injector.

Curious if you feel like your car is slower than it was stock now on map 0. I was misfiring on map 1 but had no codes. Still no codes map 0 but feels much slower than it used to. Going to replace all plugs again this weekend.

 

[DrewU272]

I was having the same misfire problems with all JB4 maps other than Map1. I read these posts and decided to install Denso 5347 IKH27 sparks set to exactly .024.
This completely solved my misfires. Now I am again experiencing the tremendous boost JB4 Map5 provides

 

[StingerT303]

Option B is we can send a 2580 with the JB4's current protection disabled. Seems our protection is more sensitive than the factory so when a plug or coil starts to fail the JB4 system picks up on it before you get major misfire codes.

What is a 2580? I'll do anything to diagnose this! I'm afraid to get on the gas even a little bit with passengers in the car...

 

[Terry@BMS]

Email me your address and we can send a 2580 to test out. It's a memory chip that goes on the JB4 board.

 

[cncBilly]

Email me your address and we can send a 2580 to test out. It's a memory chip that goes on the JB4 board.

Should we all have this?

 

[Terry@BMS]

Should we all have this?

Nope.

 

[StingerT303]

Yes! This worked! The problem is about 75% resolved. The problem is difficult to consistently recreate using Map 2 where it was almost impossible to drive before. There is still a stutter every once in a while but again, nothing like it was before. I can accept this small amount of stuttering that seems to happen around shifts. This is a huge improvement. Now my problem is my brakes warping because its too easy to get into triple digit speeds.

 

[Regs120]

75% resolved though seems like there is still a high chance you are damaging your car.