What are all the possible idle misfire causes?

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02-29-2008, 01:08 PM

#41

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2 of them. to see if that fixed the issue. It didnt, but people keep telling me its worth a shot..

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02-29-2008, 01:13 PM

#42

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is a COMP. test as good as leak down. cause two different people have done compression tests on the

car and said it looked fine. however, i over-revved my prelude a year ago and bent 4 valves pretty bad. and ever since then i had valve noise. My Audi has some valve noise at idle, is this normal for the 2.7? or could that be my answer

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02-29-2008, 10:21 PM

#43

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misfire log.... doesnt say much........

what blocks should i log for injectors and evap?

sorry, hope you guys can try to follow the log...

Friday 29 February 2008 23:42:13
8D0 907 551 M 2.7l V6/5VT G 0002

Group A: '016 Group B: '015 Group C:
Cyl 4 Cyl 5 Cyl 6 Misfire status Cyl 1 Cyl 2 Cyl 3 Misfire status
TIME 0-5 0-5 0-5 activated TIME 0-5 0-5 0-5 activated TIME
Marker STAMP STAMP STAMP
0 2 2 0 Enabled 0.49 0 0 1 Enabled
0.89 2 3 0 Enabled 1.31 0 0 1 Enabled
1.71 2 3 0 Enabled 2.11 0 0 1 Enabled
2.51 2 4 0 Enabled 2.91 0 0 1 Enabled
3.42 2 4 0 Enabled 3.92 0 0 1 Enabled
4.32 2 4 0 Enabled 4.81 0 1 1 Enabled
5.23 2 4 0 Enabled 5.61 0 1 1 Enabled
6.03 2 4 1 Enabled 6.43 0 1 1 Enabled
6.83 2 4 1 Enabled 7.24 0 1 1 Enabled
7.64 2 4 1 Enabled 8.04 0 1 1 Enabled
8.44 3 5 1 Enabled 8.84 0 1 1 Enabled
9.36 3 5 1 Enabled 9.85 0 1 1 Enabled
10.25 3 5 1 Enabled 10.65 0 1 1 Enabled
11.05 3 5 1 Enabled 11.45 0 1 1 Enabled
11.85 3 5 1 Enabled 12.25 0 1 1 Enabled
12.65 3 6 1 Enabled 13.07 0 1 1 Enabled
13.58 3 6 1 Enabled 13.98 0 1 1 Enabled
14.38 3 7 1 Enabled 14.78 0 1 1 Enabled
15.18 3 7 1 Enabled 15.58 0 1 1 Enabled
16.07 3 7 1 Enabled 16.49 0 1 1 Enabled
16.87 3 7 1 Enabled 17.29 0 1 1 Enabled
17.69 4 7 2 Enabled 18.09 0 1 1 Enabled
18.49 4 7 2 Enabled 18.89 0 1 1 Enabled
19.4 4 7 3 Enabled 19.91 0 1 1 Enabled
20.31 4 7 3 Enabled 20.71 0 1 1 Enabled
21.21 4 7 3 Enabled 21.61 0 1 1 Enabled
22.01 4 7 3 Enabled 22.41 0 1 1 Enabled
22.81 4 7 4 Enabled 23.23 0 1 1 Enabled
23.63 4 7 4 Enabled 24.03 0 1 1 Enabled
24.44 4 7 4 Enabled 24.94 0 2 1 Enabled
25.32 4 7 4 Enabled 25.74 0 2 1 Enabled
26.14 4 7 5 Enabled 26.55 0 2 1 Enabled
26.95 5 7 5 Enabled 27.45 0 2 1 Enabled
27.85 5 7 6 Enabled 28.36 0 2 1 Enabled
28.76 6 7 6 Enabled 29.26 0 2 1 Enabled
29.66 6 7 6 Enabled 30.07 0 2 1 Enabled
30.55 6 7 6 Enabled 30.97 0 2 1 Enabled
31.46 7 7 6 Enabled 31.88 0 2 2 Enabled
32.38 7 7 6 Enabled 32.89 0 2 2 Enabled
33.29 7 7 6 Enabled 33.67 0 2 2 Enabled
34.09 7 7 6 Enabled 34.49 0 2 2 Enabled
35 8 7 6 Enabled 35.4 0 2 2 Enabled
35.8 8 7 6 Enabled 36.3 0 2 2 Enabled
36.7 8 7 6 Enabled 37.1 0 2 2 Enabled
37.5 8 7 6 Enabled 37.9 0 2 2 Enabled
38.3 9 7 6 Enabled 38.71 0 2 2 Enabled
39.11 9 7 6 Enabled 39.51 0 2 2 Enabled
39.93 10 7 6 Enabled 40.33 0 2 2 Enabled
40.73 10 7 7 Enabled 41.13 0 2 2 Enabled
41.53 10 7 7 Enabled 42.02 0 2 2 Enabled
42.45 10 7 7 Enabled 42.94 0 2 2 Enabled
43.33 10 7 7 Enabled 43.73 0 2 2 Enabled
44.15 10 7 7 Enabled 44.65 0 2 2 Enabled
45.05 10 8 7 Enabled 45.45 0 2 2 Enabled
45.86 10 8 7 Enabled 46.34 0 2 2 Enabled
46.74 10 8 7 Enabled 47.16 0 2 2 Enabled
47.56 10 8 7 Enabled 47.97 0 2 2 Enabled
48.37 11 8 7 Enabled 48.87 0 2 2 Enabled
49.27 11 8 7 Enabled 49.67 0 2 2 Enabled
50.07 12 8 7 Enabled 50.47 0 2 2 Enabled

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03-01-2008, 06:32 AM

#44

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is that on cold start or with the engine warm? Show us block 032

and don't reset codes before logging that block (can be done w/ car off, key in on position)

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03-01-2008, 06:33 AM

#45

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pressure & smoke testing is easier than replacing plugs, imo.

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03-01-2008, 06:41 AM

#46

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Compression test will tell you *if* there is a problem. Leak-down test will tell you where the

problem is. For a compression test, basically you're just cranking the engine over while you hook up a pressure gauge to the spark plug hole. For a leak-down test, you are injecting pressurized air into the spark plug hole and seeing where it comes out.

Valve noise could be bad lifters. The cams actuate the valves through rockers/lifters. On newer cars, these aren't solid but oil fed to create constant pressure against the valve. Without this, there can be small clearances between the rocker/lifter resulting in valve "tap" when not properly adjusted. Sometimes the lifter oil passages get clogged and you end up with effectively a solid lifter and thus the noise. Older cars required valve adjustments every 50-80k miles or whatever to adjust the clearances.

Or it could be a bent valve =p

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03-01-2008, 05:12 PM

#47

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my dumb *** friend already reset the codes..... what should i do? should i log it anyway

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03-01-2008, 05:13 PM

#48

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yea but i dont have the tools to do the pressure test. dont know what a smoke test is really...?

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03-01-2008, 05:14 PM

#49

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well if they did a compression test already is a leak down test still a necessity?

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03-01-2008, 11:40 PM

#50

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generally you'll do a leakdown if the compression test doesn't look good

otherwise there's no point

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