Misfire after hard acceration

jrockwood · 07-31-2009, 01:53 AM

Drive around town no problems-- get on it on open road and push it to 5000rpm--bam CEL--P0305--misfire on 5. Reset no issues until hard acceleration, then CEL again. The car stumbles and then recovers. Any ideas? Plugs?-

'01tt tip 65k

iLLM3 · 07-31-2009, 04:32 AM

Plugs/Coil Packs or MAF sensor.. All can result in the same thing, is there any hesitation under boost before the CEL?

wross996tt · 07-31-2009, 11:29 AM

+1 for plugs and/or coil packs...

slant911 · 07-31-2009, 12:59 PM

+2 plugs/ coils

jrockwood · 07-31-2009, 07:23 PM

iLLM3--yes there is hesitation. Everything feels fine until I hit 4500-5000 rpm at .3-.5 bar. I shift at it smooths out.

jrockwood · 07-31-2009, 07:25 PM

What is a fair price for plugs/coil services by a good shop? Dp they have to drop the engine? I have read a couple DIY threads and seems like a major deal.

Is this part of the 60k services? I have not had it yet.

Land Jet · 07-31-2009, 07:58 PM

Plugs can be had for about $4 a piece, coils were $280 for 6 at Suncoast. The engine does not need to be dropped. The 60,000 mile service would probably be a plug change but the coils are not on any schedule that I have seen.

TT Surgeon · 07-31-2009, 08:53 PM

Probably a coil pack, but do the plugs too. The 996tt is much easier than a 997tt for the plugs.

dtmarsh · 07-31-2009, 11:26 PM

Quote:

Originally Posted by Land Jet

Plugs can be had for about $4 a piece, coils were $280 for 6 at Suncoast. The engine does not need to be dropped. The 60,000 mile service would probably be a plug change but the coils are not on any schedule that I have seen.

I just replaced my plugs w/ Bosch FR6 LDC's. Made a big diff and the hesitation/misfiring stopped. I did not replace coil packs. Dealer will charge you $710 just for labor.

slant911 · 08-01-2009, 01:50 AM

The DIY is not hard just time consuming. No engine drop required. Basically you have to take just about everything off the back end. Bumper, IC's, heat shields, etc... Nothing about it is complicated but you will need about 4-6 hours to do it the first time. Now that I know how to do it I could probably get it done in 2-3 hours or so. If it were me I'd change the coil packs and plugs. Dealer book time is 8 hours for plug change so depending on their rates (usually around $100 per hour) you are looking at around $800 in labor you can save yourself.

07-31-2009, 01:53 AM	#1
jrockwood User Join Date: Jul 2009 Posts: 14	Misfire after hard acceration Drive around town no problems-- get on it on open road and push it to 5000rpm--bam CEL--P0305--misfire on 5. Reset no issues until hard acceleration, then CEL again. The car stumbles and then recovers. Any ideas? Plugs?- '01tt tip 65k

07-31-2009, 11:29 AM	#3
wross996tt Addict Rennlist Member Join Date: Feb 2005 Location: Boulder & Santa Monica Posts: 3,617	+1 for plugs and/or coil packs... __________________ Statman 04 996TT Cab (pics) Go Buffs! Fight On!

07-31-2009, 12:59 PM	#4
slant911 Addict Rennlist Member Join Date: Nov 2001 Location: Las Vegas, NV. Posts: 1,183	+2 plugs/ coils __________________ 02' 996 TT Slate Grey Metallic UMW 1 bar program Forge DV's H and R Coilovers Clear Sidemarkers CF Interior Color Matched Twists

07-31-2009, 07:58 PM	#7
Land Jet Addict Rennlist Member Join Date: Mar 2007 Location: Maryland Posts: 1,948	Plugs can be had for about $4 a piece, coils were $280 for 6 at Suncoast. The engine does not need to be dropped. The 60,000 mile service would probably be a plug change but the coils are not on any schedule that I have seen. __________________ Larry 2002 996TT Gone but not forgotten: 1995 993 C2 Supercharged 1974 911S

07-31-2009, 08:53 PM	#8
TT Surgeon Addict Rennlist Member Join Date: Oct 2004 Location: Long Island, NY Posts: 5,795	Probably a coil pack, but do the plugs too. The 996tt is much easier than a 997tt for the plugs. __________________ Chris '07 997 TT Midnight/Sea Farnbacher-Loles prepped FVD-Brombacher 555HP Stage 2....outta control! '09 Cayenne S Blk/Blk ;wifey Rennlist member no. 041015-4836

07-31-2009, 04:32 AM	#2
iLLM3 Super User Join Date: Nov 2005 Location: NY, LI Posts: 2,015	Plugs/Coil Packs or MAF sensor.. All can result in the same thing, is there any hesitation under boost before the CEL?

07-31-2009, 07:23 PM	#5
jrockwood User Join Date: Jul 2009 Posts: 14	iLLM3--yes there is hesitation. Everything feels fine until I hit 4500-5000 rpm at .3-.5 bar. I shift at it smooths out.

07-31-2009, 07:25 PM	#6
jrockwood User Join Date: Jul 2009 Posts: 14	What is a fair price for plugs/coil services by a good shop? Dp they have to drop the engine? I have read a couple DIY threads and seems like a major deal. Is this part of the 60k services? I have not had it yet.

08-01-2009, 01:50 AM	#10
slant911 Addict Rennlist Member Join Date: Nov 2001 Location: Las Vegas, NV. Posts: 1,183	The DIY is not hard just time consuming. No engine drop required. Basically you have to take just about everything off the back end. Bumper, IC's, heat shields, etc... Nothing about it is complicated but you will need about 4-6 hours to do it the first time. Now that I know how to do it I could probably get it done in 2-3 hours or so. If it were me I'd change the coil packs and plugs. Dealer book time is 8 hours for plug change so depending on their rates (usually around $100 per hour) you are looking at around $800 in labor you can save yourself. __________________ 02' 996 TT Slate Grey Metallic UMW 1 bar program Forge DV's H and R Coilovers Clear Sidemarkers CF Interior Color Matched Twists