A Nissan Sentra Forum banner

random misfire, no check engine light

10K views 11 replies 6 participants last post by  D Man 
#1 ·
i've got an '04 spec v and it randomly misfires but isn't throwing a check engine light. i've noticed it happens after the engines up to temp and completey warm, it also only happends under 3000rpm. i can baby it up to 3K rpm's and then hammer it all the way to redline and she won't miss. i replaced all the coils, plugs 10K miles ago. i checked out live data on a scan tool and the B1S2 wasn't switching, so i replaced it. i pulled the plugs yesterday and they're white (indicating a lean mixture) i assumed it was a fuel/air volume issue because at high rpm's she runs great. ideas anyone?????
 
#5 ·
your b1s2, is referring to your o2 sensor? do you have a catless header? if you spaced out the lower o2, the readings will be different. if anything the first o2 would be controlling the a/f ratio. you could make sure it isnt caked up with white shite either. also i wouldnt rule out cam and crank sensors if you havent changed those yet, you will notice an intermittent rough idle when they are failing. the last thing i can think of is the alternator not outputting at lower rpm, check the battery voltage with the motor on and off.
 
#6 ·
I used to have the same issue last month with my '04 sentra Specv. I changed the spark plug, coils and wire initially and used the seafoam treatment after it.

One battle to clean up fuel injector and another to clear carbon build up. It seems to be working fine for me:)
 
#9 ·
i replaced the crank sensor last night, drove the car for about 20min and now it misses at around 4000rpm's (at full throttle) but never missed at low rpm's like before... note my idle did seem more steady although i didn't do the 3 relearns??? i've never heard of these
 
#11 ·
#12 ·
i feel like a complete n00b right now but the misfire was caused by a coil going bad. actually it was 2 coils. i was swapping out coils to see if one was bad and one of the ones i was using to swap out with was also bad. thanks for all the info though. it's greatly appreciated
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top