POLL: What injectors do you have and do you experience cold start misfires?
08-25-2006, 11:24 AM
#11
Member
Thread Starter
Join Date: Aug 2006
Posts: 2,686
Likes: 0
Received 0 Likes
on
0 Posts
If I didn't get codes and occasional CEL, wouldn't give two *****.
Hell, I probably wouldn't even know...like you said.
I just want to be sure it's not a symptom of some other problem...or that it's causing some sort of damage. I'm not smart enough so needs others to calm my nerves. ;-)
I just want to be sure it's not a symptom of some other problem...or that it's causing some sort of damage. I'm not smart enough so needs others to calm my nerves. ;-)
08-25-2006, 11:28 AM
#12
AudiWorld Super User
Join Date: Dec 2002
Posts: 2,718
Likes: 0
Received 0 Likes
on
0 Posts
Here is what i am thinking.....
I am wondering if there is a connection to the 00 vs 02 intake manifold style or/and PCV / Spider hose style.
I can tell you one thing. I had some rough idle when I was STOCK w/ and with out colder plugs. I am very picky and got the dealer to replace many parts on my car and they still could not get it as good as I would EXPECT it to be for a $30+ K car.
I finally settle on this setup on the STOCK ECU `A" box, NEW version. (I am told that A box has 2 versions, ver 2 and 3)
<img src="http://homepage.mac.com/edyjun1/S4/Logs/66-68%20Deg%20-%2012%20tank%20of%2091%20Oct%20GIAC%20X%20MBC%20st and%20alone%20%20-%20NO%20TDC/66-68%20Deg%20-%20GIAC%20X%20MBC%20stand%20alone_files/image026.gif">
The dealer also changed my ECU, same "A" box but once it was replace it was smother. Currently I have GIAC X ver 8 (Flashed) "A" box and the ver 3 "A" Box Stock. I have to say the STOCK Ver 3 "A" box is smoother at idle than the GIAC X w/ the same setup.
I think there is a difference in the code that the ECU is using that is directly causing rough idle, I know GIAC X old ver have a rough idle but the new ones not so much. (old ver of XR vs the new XR as well) I have talked to Jeff Moss about this and he said that when they release a new ver of a chip they use the latest STOCK code. Meaning if you have an M Box Stock ECU ver 2 and there is a Ver 3 for the same M box, when you get the latest GIAC X chip your new code will have the NEW M box code as well, ver 3.
That is why I think car year and ECU/ Chip ver also makes a dif.
Edy
I can tell you one thing. I had some rough idle when I was STOCK w/ and with out colder plugs. I am very picky and got the dealer to replace many parts on my car and they still could not get it as good as I would EXPECT it to be for a $30+ K car.
I finally settle on this setup on the STOCK ECU `A" box, NEW version. (I am told that A box has 2 versions, ver 2 and 3)
<img src="http://homepage.mac.com/edyjun1/S4/Logs/66-68%20Deg%20-%2012%20tank%20of%2091%20Oct%20GIAC%20X%20MBC%20st and%20alone%20%20-%20NO%20TDC/66-68%20Deg%20-%20GIAC%20X%20MBC%20stand%20alone_files/image026.gif">
The dealer also changed my ECU, same "A" box but once it was replace it was smother. Currently I have GIAC X ver 8 (Flashed) "A" box and the ver 3 "A" Box Stock. I have to say the STOCK Ver 3 "A" box is smoother at idle than the GIAC X w/ the same setup.
I think there is a difference in the code that the ECU is using that is directly causing rough idle, I know GIAC X old ver have a rough idle but the new ones not so much. (old ver of XR vs the new XR as well) I have talked to Jeff Moss about this and he said that when they release a new ver of a chip they use the latest STOCK code. Meaning if you have an M Box Stock ECU ver 2 and there is a Ver 3 for the same M box, when you get the latest GIAC X chip your new code will have the NEW M box code as well, ver 3.
That is why I think car year and ECU/ Chip ver also makes a dif.
Edy
08-25-2006, 11:32 AM
#14
AudiWorld Senior Member
Join Date: Dec 2002
Posts: 1,705
Likes: 0
Received 0 Likes
on
0 Posts
I have run 3 injectors (other than stock) GTs, Delphi42s, and now GGs
they all misfire to some extent on my car. But the GGs by far the least and they are buttery smooth.
08-25-2006, 11:39 AM
#17
AudiWorld Super User
Join Date: Mar 2000
Posts: 9,779
Likes: 0
Received 0 Likes
on
0 Posts
RS4 injs are nice though, at least on mine. Not a single missfire now(well maybe one or two a min or
so watching both banks with the VAG). I had a vac leak post maf that was causing missfires on mine after I put the kit on. Fixing that has eliminated all of mine.
My car had missfires prior on stock injectors though both on stock and Stg2 code(M box) so I don't think its all injectors in some cases.
My car had missfires prior on stock injectors though both on stock and Stg2 code(M box) so I don't think its all injectors in some cases.
08-25-2006, 11:45 AM
#20
Member
Thread Starter
Join Date: Aug 2006
Posts: 2,686
Likes: 0
Received 0 Likes
on
0 Posts
Right now at 460cc/min, I'm sometimes hovering near 100% DC and at -20.5%...
I'd like to keep AFR about the same, not go over 100% DC, and don't want to change housing so only 4.5% of fuel left to pull.
That means I'd like to stay with a similar flow rate. I've heard TT225s are ~445cc/min@4bar, GGs are ~450cc/min@3bar, RS4s are ~480cc/min.
I don't want to go as low as 440, can't go too high where I'll be too rich at -25%.
That means I'd like to stay with a similar flow rate. I've heard TT225s are ~445cc/min@4bar, GGs are ~450cc/min@3bar, RS4s are ~480cc/min.
I don't want to go as low as 440, can't go too high where I'll be too rich at -25%.