Hmm. . . May try that with spark plugs lol
Because it's a "bandaid" and it proper. I had to do it on my 900hp dsm.
Cyl 6 misfire
- Thread starter N54gasm
- Start date
Hmm. . . May try that with spark plugs lol
Because it's a "bandaid" and it proper. I had to do it on my 900hp dsm.
Still having this damn misfire on cyl 6. Any other suggestions? Here is a log (still on a base tune as were trying to solve this damn misfire)
So an update. Switched to a jb4 e85/pi bef just for shits and giggles, and the damn misfired transfered to now being ONLY cyl 5. . . lol im at a loss
I could be wrong but what I imagine is happening is the dmfw is designed to dampen vibration due to acceleration of crank during piston firing which works great at low rpm and lower power levels. Our dme detects misfire not knock by picking up on a lack of acceleration at the crank for a certain duration so high power cars gain the ability at high rpm to accelerate the crank so fast that the springs no longer can rebound back to nuetral position so when the next cylinder fires the spring has no more travel which in turn allows the springs to return to nuetral next power stroke. It's really hard to put into words but if you visualize you can see how the dme would see inconsistent speeds which would read as complete misfire or incomplete burn. I'm sure false knock could also come about from harmonics but that could easily be fixed with cans on the dyno
It was apparently JB4 settings. Jon helped me get my trims in spec, and I kept an eye on my hpfp and trims and adjusted fuel bias, and that was it. Apparently it misfired beforehand either being too rich/lean. I could only do 4-5 pulls as it rained, but as of those 4-5 pulls it didnt misfire, so its a plus!
Right! Was going crazy over this damn misfire haha. Countless dollars later replacing damn near everything because I was told it was hardware related. . . But hey, "maintenance" haha
This was most likely my issue. I kept pushing the car each round to test things out, then finally it gave out. My initial issue was only cyl 6 misfire.what item from your logs, did your tuner reference?
The old tuner said it wasnt the tune that it was hardware related. But after changing EVERYTHING related to cyl 6, and all test's checked out (compression, leakdown) I thought otherwise. Then when changing to the bms e85 bef, it changed to only cyl 5 misfire and 6 never misfired again. Coming from that, I KNEW it was a jb4 setting/tuner issue. So I talked to Jon Russell, and mentioned the trims and gave me some pointers and how to get the trims to level out and to aim for a value of 25. After I did that, never had another misfire.
Exactly. But previous tuner said it wasn't tune related lol. After I looked at the logs and asked some advice from other knowledgable tuners, for it solved. My car just so happens to be like a woman on her period, very picky and emotional lol
Figure id update this. The misfire did go away, but then came back. After replacing everything it HAD to be phantom knock as it was pulling timing on cyl5. Comp and leakdown is damn near perfect so its not an engine issue. Disabled misfire detection above 6k and she pulled good (can tell if a engine is misfiring). It pulled good. While changing stuff I also swapped the pr coil from cyl5 to cyl2. Well while cyl5 is still pulling timing (not as much) the engine started to misfire on cyl1. WTF, NEVER had a misfire on cyl1. So after troubleshooting, the only thing I did not replace was the pr coils. . .
Bought new stock coils, regapped plugs to .020 and bam, didnt have a misfire of the 8 pulls pretty much back to back. Whereas before it was like every other pull basically.
Bought new stock coils, regapped plugs to .020 and bam, didnt have a misfire of the 8 pulls pretty much back to back. Whereas before it was like every other pull basically.
Last edited:
Similar threads
Technical
Strange - N54 29CD Misfire Cyl. 1
