POLL: What injectors do you have and do you experience cold start misfires?

PSmalls::AnalRetentiveNumbNut · 08-25-2006, 10:37 AM

I have 38# Delphi injectors at 4bar (460cc/min) and I'm starting to have coldstart misfires more frequently again....this problem went away for quite a while and has now returned.

When I don't have VAG hooked up watching blocks 014/015/016, you'd think the car was perfect...runs as smooth as stock in all conditions, don't feel a single misfire.

When I have VAG hooked up watching those blocks, I see sometimes up to 75 misfires on the 1st cycle very evenly assorted across cylinders (although 2,5,6 act up the most).

Just recently, I pulled codes and had 7 (misfires on all 6 cylinders, plus random misfire). On occasion, I'll even get a solid CEL for these codes when pulling out of my driveway.

It doesn't bother me tremendously as drivability is not the least bit affected as far as I can tell. I'm just curious whether it's my injectors (had same problem with 36# bluetops though...and there are cases of people running either of these injectors without my issue) or I need to chase something else. I'm also looking to see how common this is.

What frustrates me more than anything is I will ride in cars that idle rougher than my own, yet they don't throw a single code/CEL or even register many/any misfires in VAG blocks. Even other people that drive my car never feel the misfires as I'm watching them via VAG.

Que homebrew haters, but I don't see this as being the problem. There are so many homebrew cars out there with greentops, GGs, 36# Bluetops, 38# Delphis, 42# Delphis, etc that are not experiencing this (or at least not speaking up about their experiences).

Thanks.

BTW, Piggie pulled a couple of the plugs (looked good) and swapped a couple coilpacks (cyl 5 and cyl6 when it was most predominantly cyl6) last time I saw him.

lemieux@curbside · 08-25-2006, 10:52 AM

EdyJun · 08-25-2006, 10:52 AM

PSmalls::AnalRetentiveNumbNut · 08-25-2006, 10:54 AM

I never experienced misfires on stock injectors and Platins.

PSmalls::AnalRetentiveNumbNut · 08-25-2006, 10:55 AM

S4AVT · 08-25-2006, 10:57 AM

PSmalls::AnalRetentiveNumbNut · 08-25-2006, 11:19 AM

I'll be sure to let you know what affect it has. It's been suggested to me that I add 5%-10% on each.

DAP@EPL · 08-25-2006, 11:21 AM

nyet · 08-25-2006, 11:23 AM

just nobody bothers looking unless they throw codes or the car doesn't drive right.

i have occasional cold start misfires. once egts get to temp im fine tho.

PSmalls::AnalRetentiveNumbNut · 08-25-2006, 11:23 AM

hence the for sale/trade ad in my sig.

08-25-2006, 10:37 AM	#1
PSmalls::AnalRetentiveNumbNut Member Account #: 112331 Join Date: Aug 2006 Posts: 2,690	POLL: What injectors do you have and do you experience cold start misfires? I have 38# Delphi injectors at 4bar (460cc/min) and I'm starting to have coldstart misfires more frequently again....this problem went away for quite a while and has now returned. When I don't have VAG hooked up watching blocks 014/015/016, you'd think the car was perfect...runs as smooth as stock in all conditions, don't feel a single misfire. When I have VAG hooked up watching those blocks, I see sometimes up to 75 misfires on the 1st cycle very evenly assorted across cylinders (although 2,5,6 act up the most). Just recently, I pulled codes and had 7 (misfires on all 6 cylinders, plus random misfire). On occasion, I'll even get a solid CEL for these codes when pulling out of my driveway. It doesn't bother me tremendously as drivability is not the least bit affected as far as I can tell. I'm just curious whether it's my injectors (had same problem with 36# bluetops though...and there are cases of people running either of these injectors without my issue) or I need to chase something else. I'm also looking to see how common this is. What frustrates me more than anything is I will ride in cars that idle rougher than my own, yet they don't throw a single code/CEL or even register many/any misfires in VAG blocks. Even other people that drive my car never feel the misfires as I'm watching them via VAG. Que homebrew haters, but I don't see this as being the problem. There are so many homebrew cars out there with greentops, GGs, 36# Bluetops, 38# Delphis, 42# Delphis, etc that are not experiencing this (or at least not speaking up about their experiences). Thanks. BTW, Piggie pulled a couple of the plugs (looked good) and swapped a couple coilpacks (cyl 5 and cyl6 when it was most predominantly cyl6) last time I saw him.

08-25-2006, 10:52 AM	#2
lemieux@curbside AudiWorld Super User Account #: 47312 Join Date: Dec 2002 Posts: 17,783	green tops misfired on me too .. what plugs are you using ? maybe the pugs are too cold __________________ ************************************************ ************************************* "it's a B5 S4 ,it may break down, but its far enough ahead, by the time its fixed, you still haven't caught up." -best line i've heard ;) AUDI B5 S4 detail info (pdf file) that everyone should read and have saved on his computer AUDI B5 RS4 study guide detail info (pdf file) FATS database VAG-COM LOCATOR ASP Hands down the "BESTEST" tuner out there.

08-25-2006, 10:52 AM	#3
EdyJun Member Account #: 48484 Join Date: Dec 2002 Posts: 2,849	Sir, what year is your car? __________________ 2000 Audi S4 STG 3 FATS = 3.66 w/ 91 oct AIM: EdyJun 11 September 2001 In their honor. In their memory. <font color="red">---------------------------------------------------------- <u><big> <a href="http://homepage.mac.com/edyjun1/S4/index.htm">EdyJun's S4 Directory (FAQ, DIY, Info, Tips and Help) </a> </big> </u>---------------------------------------------------------- </font>

08-25-2006, 10:54 AM	#4
PSmalls::AnalRetentiveNumbNut Member Account #: 112331 Join Date: Aug 2006 Posts: 2,690	Bosch Platins, had them since ~12K miles, ~40K miles on them now. I never experienced misfires on stock injectors and Platins.

08-25-2006, 10:55 AM	#5
PSmalls::AnalRetentiveNumbNut Member Account #: 112331 Join Date: Aug 2006 Posts: 2,690	2001.5, why do you ask?

08-25-2006, 10:57 AM	#6
S4AVT Member Account #: 71765 Join Date: Mar 2004 Posts: 3,425	I have Delphi #42, and I have exactly same issue as you are having....

08-25-2006, 11:19 AM	#7
PSmalls::AnalRetentiveNumbNut Member Account #: 112331 Join Date: Aug 2006 Posts: 2,690	After all of this extremely helpful info, going to try bumping up cold/warm-up start channels a bit. I'll be sure to let you know what affect it has. It's been suggested to me that I add 5%-10% on each.

08-25-2006, 11:21 AM	#8
DAP@EPL Audiworld Sponsor Account #: 6924 Join Date: Jun 2000 Posts: 19,701	60# Siemens Deka@4bar (~700 cc/min). No cold start problems. __________________

08-25-2006, 11:23 AM	#9
nyet Member Account #: 13093 Join Date: Dec 2000 Posts: 33,114	i dont think coldstart misfires are uncommon, even in OTS kits just nobody bothers looking unless they throw codes or the car doesn't drive right. i have occasional cold start misfires. once egts get to temp im fine tho. __________________ ------------------------------------- "It's easier to practice medicine without a license in this country than it is to get info on tuning Motronic." -JasonS9 ECUxPlot - my java based ECUx/VAGCOM/VCDS plotter My hacked version of Flyboy's ECUx template. S4Wiki - CONTRIBUTE TODAY! Web based FATS calculator for ECUx and VAGCOM logfiles Sync your iPod under Linux! Definitive S4 DIY Thread of Doom AWOT Brain Trust #101 AWOT Axis of Evil Member #6 Member, Aw0t Fish Taco Dinner Club I say to you that the VCR is to the American film producer and the American public as the Boston strangler is to the woman home alone." - Jack Valenti, President and CEO of the MPAA this site is NOT for information sharing it's strictly for multiple monologues that result in none of the participants changing their point of view - frank

08-25-2006, 11:23 AM	#10
PSmalls::AnalRetentiveNumbNut Member Account #: 112331 Join Date: Aug 2006 Posts: 2,690	If I had more flow, I'd definitely be running those. Instead, gotta settle for something smaller... hence the for sale/trade ad in my sig.

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