sudden missfire going into 4th?

ksalih · 06-11-2012, 01:11 AM

Hey all. Just yesterday I noticed going into 4th WOT caused a sudden jerk and could feel a missfire as I slowed down and my idle was terrible. Proceeded to shut her off and she started up without issues. Happened again today, going into 4th. It seems like my boost spikes up between gears. (mind you this is an auto, using the paddles). if I let off the gas instead of going WOT, this issues doesn't occur. Soon as I WOT and don't let off when shifting, I will sometimes get this issue and sudden jerk like I was hit from behind. Any ideas? 08, JB4 map 2, bms dci and Dp's. appreciate any info.

enrita · 06-11-2012, 01:26 AM

Its a missfire, check which cylinder and if it happens always on that one.
How old are the plugs? Try to switch coil, if the missfire jumps to the cylinder you switched the coil than replace it.

benzy89 · 06-11-2012, 09:33 AM

Misfires -- Check your codes & see what cylinders are giving you trouble. Could be any combination of: spark plugs, ignition coils and/or fuel injectors.

Best way to determine what needs to be replaced is by shuffling your ignition coils around (number them before you do this so you can keep track of them). If the misfire follows the coil then it's that, if it stays on the same cylinder then it's a plug.

ksalih · 06-11-2012, 12:49 PM

Okay, plugs have less than 4k miles on them. Ill swap my coils around to see if I can isolate it. I appreciate the quick replies.

06-11-2012, 01:11 AM	#1
ksalih Lieutenant 71 Rep 510 Posts Drives: 2018 M2 LCI Join Date: Mar 2012 Location: Gilbert, AZ iTrader: (1)	sudden missfire/jerk when WOT into 4th. Hey all. Just yesterday I noticed going into 4th WOT caused a sudden jerk and could feel a missfire as I slowed down and my idle was terrible. Proceeded to shut her off and she started up without issues. Happened again today, going into 4th. It seems like my boost spikes up between gears. (mind you this is an auto, using the paddles). if I let off the gas instead of going WOT, this issues doesn't occur. Soon as I WOT and don't let off when shifting, I will sometimes get this issue and sudden jerk like I was hit from behind. Any ideas? 08, JB4 map 2, bms dci and Dp's. appreciate any info. __________________ '2018 F87 M2 LCI \| LBB \| GC Camber Plates \| Ohlins R&T 90/190N/mm \| 18x10 et33 square 275/35 \| MPe \| Poly Transmission Mounts \| Recaro Sportster CS
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06-11-2012, 01:26 AM	#2
enrita Major General 161 Rep 7,377 Posts Drives: 335i - Big turbos Join Date: Sep 2008 Location: Italian in Sweden iTrader: (0)	Its a missfire, check which cylinder and if it happens always on that one. How old are the plugs? Try to switch coil, if the missfire jumps to the cylinder you switched the coil than replace it. __________________ 07 335i AT - MOTIV 750 - MHD E85 BMS flash - BMS PI - JB4G5 - Okada Coils - NGK 5992 Plugs - Helix IC - Snow Stg. 3 - Stett CP - Custom midpipes with 100 HJS Cats - Bastuck Quad - PSS10 - QUAIFE LSD - BMS OCC - Forge DVs - AR OC - ALCON BBK - M3 Chassi - Dinan CP - Velocity M rear Toe arms - Advan RZ-DF - LUX H8 - Level 10 AT upgrade
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06-11-2012, 09:33 AM	#3
benzy89 Banned 79 Rep 2,396 Posts Drives: '08 E90 335i Join Date: Jan 2012 Location: Northern NJ iTrader: (3) Garage List 2008 BMW 335i [7.50]	Misfires -- Check your codes & see what cylinders are giving you trouble. Could be any combination of: spark plugs, ignition coils and/or fuel injectors. Best way to determine what needs to be replaced is by shuffling your ignition coils around (number them before you do this so you can keep track of them). If the misfire follows the coil then it's that, if it stays on the same cylinder then it's a plug.
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06-11-2012, 12:49 PM	#4
ksalih Lieutenant 71 Rep 510 Posts Drives: 2018 M2 LCI Join Date: Mar 2012 Location: Gilbert, AZ iTrader: (1)	Okay, plugs have less than 4k miles on them. Ill swap my coils around to see if I can isolate it. I appreciate the quick replies. __________________ '2018 F87 M2 LCI \| LBB \| GC Camber Plates \| Ohlins R&T 90/190N/mm \| 18x10 et33 square 275/35 \| MPe \| Poly Transmission Mounts \| Recaro Sportster CS
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