2002 LS1 A4 Stumble During Idle
03-20-2013, 07:49 AM
#1
Staging Lane
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2002 LS1 A4 Stumble During Idle Good Morning,
Just like the title says, I have a 2002 A4 with and idle that consistently stumbles during idle. I would appreciate any help rooting out possible causes and have provided a listing of clues if it might help someone narrow it down. Thanks in advance!!
1) It's been doing this since I bought the car in February of 2012 but in the year+ I've had it, it hasn't gotten any worse.
2) Changed the plugs to NGK TR55IX last year and that didn't help, just changed them again last week to Denso Iridium’s and that had no affect either.
3) Changed wire to MSD with no effect.
4) Just replaced both front 02s (back one's have been deleted in a tune)
5) Idle only stumbles once the car is warmed up (the first few minutes after I crank it the idle is strong and smooth)
6) Bolt-on car: Lid, Loudmouth, Ported TB, Composite MAF ends, Pacesetter LT's
7) The Air/Fuel ratio stayed consistent across the range on the dyno
8) If I put the car under heavy load (like uphill) in high gear it's smooth as butter, but if I let the car coast slightly downhill without pressing the gas, it will surge a little.
9) The stumble is not very pronounced. I've had two mechanics listen to it and they both had to sit in the car and listen for a minute while I pointed out the pattern. One eventually said it was a slight miss, the other said it was nothing.
Sorry for the lengthy post and again, thank you for any help. I've been chasing this thing forever and it's driving me crazy.
Just like the title says, I have a 2002 A4 with and idle that consistently stumbles during idle. I would appreciate any help rooting out possible causes and have provided a listing of clues if it might help someone narrow it down. Thanks in advance!!
1) It's been doing this since I bought the car in February of 2012 but in the year+ I've had it, it hasn't gotten any worse.
2) Changed the plugs to NGK TR55IX last year and that didn't help, just changed them again last week to Denso Iridium’s and that had no affect either.
3) Changed wire to MSD with no effect.
4) Just replaced both front 02s (back one's have been deleted in a tune)
5) Idle only stumbles once the car is warmed up (the first few minutes after I crank it the idle is strong and smooth)
6) Bolt-on car: Lid, Loudmouth, Ported TB, Composite MAF ends, Pacesetter LT's
7) The Air/Fuel ratio stayed consistent across the range on the dyno
8) If I put the car under heavy load (like uphill) in high gear it's smooth as butter, but if I let the car coast slightly downhill without pressing the gas, it will surge a little.
9) The stumble is not very pronounced. I've had two mechanics listen to it and they both had to sit in the car and listen for a minute while I pointed out the pattern. One eventually said it was a slight miss, the other said it was nothing.
Sorry for the lengthy post and again, thank you for any help. I've been chasing this thing forever and it's driving me crazy.
03-24-2013, 10:02 PM
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Staging Lane
Join Date: Mar 2013
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I had the same issue. If you gave it gas, then let it idle, it was lull during idle. The RPM's would drop for a second then it would right itself.
I just had mine tuned, and they got rid of this during the tune.
I just had mine tuned, and they got rid of this during the tune.
