Misfire/backfire
#1
Misfire/backfire
Hey guys, so I've been having a misfire/backfire issue that came out of nowhere and is driving me nuts... First step I changed the plugs and gapped them to .025, with no change. From there myself and a buddy of mine did a compression test with values within ~5psi of each other (I forget the exact values) but looked good. After that we checked both cam sensors, the crank sensor, and TPS with an oscillometer and all showed nice square waves. We checked, and I'm getting a nice spark from the Spoolinup COP through the plugs. I checked timing, and all marks matched up on the cam gears and trigger plate with no play in the trigger plate. We checked the injectors, and cleaned them up with no change. I'm kind of at a loss where to look next, as I'm now starting to think it may just be in the tune? When the car is idling the AFR's are all over the place, and while running the car is pig rich. The misfire happens when free revving in neutral or in gear, but always happens between 3-4,000rpm's but clears up immediately after and pulls hard, just rich. Also, my car is on tuned on speed density. If anyone has any suggestions, it would be greatly appreciated as I'm about out of ideas. Perhaps I overlooked something, but at this point I'm just not sure where to look next. Thank you in advance!
The following users liked this post:
Turndown (Jul 29, 2017)
#6
Well, I was finally able to get a log after a couple "speed bumps", I'll call them, in my build. Anyways, here it is... I'm new to evoscan/ecuflash so bear with me as I'm a bit slow with computers and programs. If anyone sees anything that stands out as a potential cause please let me know
#7
EvoM Guru
iTrader: (7)
Well, I was finally able to get a log after a couple "speed bumps", I'll call them, in my build. Anyways, here it is... I'm new to evoscan/ecuflash so bear with me as I'm a bit slow with computers and programs. If anyone sees anything that stands out as a potential cause please let me know
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#8
I had all of that stuff turned on I'm not sure why it's not displaying the values. My O2 won't be displayed as I have no exhaust on the car yet. I'm trying to get it diagnosed while I wait for Robispec to send my coilovers back which I need so I can bring the car to get the DP made.
The following users liked this post:
Turndown (Jul 29, 2017)