Need experts -- advanced idle issue! help!
08-02-03, 11:14 AM
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Rotary Freak
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Need experts -- advanced idle issue! help!
My misfire issue is still not resolved
I've been dealing with this for quite a while with my s5 t2
Symptoms?
1. Misfire when revving in neutral above 1k (not backfire, just misfire)
2. Misfire upon decelleration when revving in neutral (series of popping sounds)
3. Rough idle upon warm restart on a hot day (i imagine due to heat soak), goes away after 10 seconds of driving.
4. Low vacuum upon warm restart/hot day. (14 in/hg as opposed to 17-19 in/hg normally) Although the AFM reading on the AFC shows more flow than normal idle.
5. Intermittent loud buzzing sound from the ACV. Seems to be related to misfiring, but i can't figure out how.
What have i done?
1. Set the TPS 104132519073590813906908136 times
2. Pulled the BAC off and tested it, works flawlessly, and is clean as a whistle.
3. AFM is not sticking.
4. Replaced vacuum lines around acv, all except the bottom one which i couldnt reach.
5. Checked throttle cable for stickyness/adjusted.
6. Checked dashpot
7. Re-did grounds (two VERY good grounds, in addition to the stock grounds)
8. Checked vacuum leaks as best as i could using propane and water.
Oh by the way, the issue diminishes when the A/C is on (BAC giving the engine more air).
Suspects?
A) Injectors
B) ACV diaphragm busted
No backfires when shifting, shitty MPG.
I just bought a new ACV ... the current one is buzzing so i dunno if that's the problem or not. Perhaps there's an internal vacuum leak.
The issue is nonexistant for the first 30 seconds of the car's startup. Meaning, no misfire, just runs/idles like a dream!!!
Then all of a sudden, the idle goes up about 200rpm, and stays steady, but starts misfiring/smelling rich. At 750RPM, there are no misfires. As well with the A/C on, there are no misfires, no matter what rpm.
WTF could it be? on cold startups, what the fack runs for the first 30 seconds and then stops? What could this POSSIBLY be?
Thanks!
-Ross
I've been dealing with this for quite a while with my s5 t2
Symptoms?
1. Misfire when revving in neutral above 1k (not backfire, just misfire)
2. Misfire upon decelleration when revving in neutral (series of popping sounds)
3. Rough idle upon warm restart on a hot day (i imagine due to heat soak), goes away after 10 seconds of driving.
4. Low vacuum upon warm restart/hot day. (14 in/hg as opposed to 17-19 in/hg normally) Although the AFM reading on the AFC shows more flow than normal idle.
5. Intermittent loud buzzing sound from the ACV. Seems to be related to misfiring, but i can't figure out how.
What have i done?
1. Set the TPS 104132519073590813906908136 times
2. Pulled the BAC off and tested it, works flawlessly, and is clean as a whistle.
3. AFM is not sticking.
4. Replaced vacuum lines around acv, all except the bottom one which i couldnt reach.
5. Checked throttle cable for stickyness/adjusted.
6. Checked dashpot
7. Re-did grounds (two VERY good grounds, in addition to the stock grounds)
8. Checked vacuum leaks as best as i could using propane and water.
Oh by the way, the issue diminishes when the A/C is on (BAC giving the engine more air).
Suspects?
A) Injectors
B) ACV diaphragm busted
No backfires when shifting, shitty MPG.
I just bought a new ACV ... the current one is buzzing so i dunno if that's the problem or not. Perhaps there's an internal vacuum leak.
The issue is nonexistant for the first 30 seconds of the car's startup. Meaning, no misfire, just runs/idles like a dream!!!
Then all of a sudden, the idle goes up about 200rpm, and stays steady, but starts misfiring/smelling rich. At 750RPM, there are no misfires. As well with the A/C on, there are no misfires, no matter what rpm.
WTF could it be? on cold startups, what the fack runs for the first 30 seconds and then stops? What could this POSSIBLY be?
Thanks!
-Ross
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