unstable idle
#13
10-30-2006, 03:39 PM
RE: unstable idle
HI,
I did some logging with the VAG-Com during the weekend. I did the full thottle test of the MAF to check its operation. The following is the log file for blocks 1, 2 and 3. I had cleaned the MAF before doing the test.
Monday,30,October,2006,16:15:27
8D0 907 557 C,,1.8L R4/5V MOTR HS D08,
,Group A:,'001,,,,Group B:,'002,,,,Group C:,'003
,,Engine RPM,Engine load,Throttle angle,Ignition timing,,Engine RPM,Engine load,Inj. period,Mass air flow,,Engine RPM,Battery voltage,Coolant temp -G62,Intake air temp
,TIME, 820..900, 0.85..2.50, 0..5,12deg BDTC,TIME, 820..900, 0.85..2.50 , 2.0..5.0, 2.0..4.0,TIME, 820..900,10.0..14.5, 80..105,19.5=>see lbl file
Marker,STAMP, /min, ms,°, °ATDC,STAMP, /min, ms, ms, g/s,STAMP, /min, V,°C,°C
,140.91,1640,3.30,20.8,26.3,141.22,2000,1.75,2.32, 2.29,141.57,1680,13.940,64.5,19.5
,141.89,1320,1.05,6.9,18.0,142.22,1080,1.45,2.49,4 .65,142.58,800,13.940,64.5,19.5
,142.98,880,2.70,4.8,12.8,143.34,920,1.75,3.44,2.5 7,143.64,760,13.940,64.5,19.5
,143.99,640,2.00,9.1,20.3,144.30,680,2.55,4.82,4.3 1,144.68,800,14.008,64.5,19.5
,145.02,800,1.85,5.2,17.3,145.39,720,1.80,3.61,3.2 6,145.73,560,13.872,64.5,19.5
,146.12,800,2.85,3.5,18.8,146.45,880,1.90,3.44,3.0 6,146.85,720,13.940,64.5,19.5
,147.19,720,2.20,7.4,21.8,147.54,760,2.15,3.44,3.4 0,147.89,760,13.940,64.5,19.5
,148.27,680,2.20,9.1,20.3,148.62,760,2.30,3.61,3.6 1,149.01,800,13.940,64.5,19.5
,149.39,760,2.15,7.8,23.3,149.76,760,2.20,3.44,3.9 6,150.10,760,13.940,64.5,19.5
,150.39,800,2.20,8.2,22.5,150.71,840,2.15,3.53,3.8 9,151.06,840,13.940,64.5,19.5
,151.37,840,2.15,8.2,15.0,151.67,800,2.20,3.61,4.0 9,152.03,840,14.008,64.5,19.5
,152.34,840,2.20,8.7,13.5,152.65,840,2.15,3.70,4.0 9,152.95,800,13.940,64.5,19.5
50,476.65,840,2.25,8.7,12.8,476.99,840,2.25,3.78,4 .31,477.31,840,13.668,70.5,19.5
,477.65,840,2.30,8.7,14.3,478.03,840,2.30,3.70,4.3 1,478.40,840,13.736,70.5,19.5
,478.75,840,2.30,8.7,12.8,479.07,840,2.25,3.78,4.3 1,479.46,840,13.804,70.5,19.5
,479.79,840,2.30,8.7,12.8,480.13,840,2.25,3.61,4.2 3,480.44,840,13.804,70.5,19.5
,480.81,840,2.30,8.7,12.8,481.13,840,2.35,5.93,6.8 7,481.48,1040,13.804,70.5,19.5
,481.88,1600,2.45,8.2,27.0,482.23,1280,1.45,2.67,3 .82,482.55,960,13.736,70.5,19.5
,482.94,880,2.10,8.2,18.0,483.29,840,2.10,3.27,4.0 3,483.59,680,13.736,70.5,19.5
,484.00,560,2.85,11.7,12.8,484.37,680,3.40,6.02,4. 86,484.76,920,13.736,70.5,19.5
,485.14,1080,2.45,9.5,20.3,485.49,1080,1.85,2.67,3 .47,485.85,880,13.736,70.5,19.5
,486.14,640,2.00,10.0,21.0,486.45,480,3.55,8.00,8. 12,486.78,640,13.260,70.5,19.5
,487.08,840,3.40,10.0,3.8,487.43,1080,2.65,3.96,4. 37,487.75,1040,13.804,70.5,19.5
,488.07,920,2.00,8.2,20.3,488.39,800,2.30,4.47,5.9 7,488.68,880,13.736,70.5,19.5
,489.02,1440,3.70,18.7,21.0,489.36,1800,2.85,4.64, 9.79,489.73,1880,13.736,70.5,19.5
,490.06,1800,2.90,23.0,30.8,490.42,1800,3.55,7.31, 16.39,490.76,1920,13.736,70.5,19.5
,491.10,1840,5.60,35.6,19.5,491.45,1640,6.05,11.35 ,22.36,491.82,1800,13.736,70.5,19.5
,492.15,2200,6.55,48.6,21.8,492.53,2560,6.80,12.30 ,38.75,492.87,2800,13.736,70.5,19.5
,493.26,2520,0.80,5.6,15.0,493.60,1720,6.65,14.88, 30.34,493.91,2040,13.736,70.5,19.5
,494.29,2240,7.05,82.9,23.3,494.62,2400,7.20,13.76 ,39.51,494.97,2600,13.804,70.5,19.5
,495.34,2800,7.45,83.3,23.3,495.70,3040,7.60,14.79 ,50.34,496.06,3240,13.736,70.5,19.5
,496.46,3480,8.00,83.3,24.8,496.83,3720,8.20,16.25 ,69.09,497.21,4000,13.736,70.5,19.5
,497.60,4240,9.10,83.3,18.8,497.99,4520,9.00,17.20 ,89.65,498.33,4760,13.668,70.5,19.5
,498.70,5000,8.45,83.3,24.0,499.03,5200,8.35,16.25 ,93.47,499.39,5440,13.668,70.5,19.5
,499.74,5640,8.50,83.3,29.3,500.09,5880,8.45,16.60 ,104.23,500.45,6040,13.668,70.5,19.5
,500.79,6200,8.05,83.3,30.0,501.16,5840,0.80,0.95, 9.09,501.50,5160,13.804,70.5,19.5
,501.87,4120,3.20,44.3,24.0,502.30,4320,8.60,15.65 ,81.59,502.68,4440,13.736,70.5,19.5
,503.09,4560,8.65,65.1,18.8,503.47,4360,1.05,0.95, 6.53,503.84,3800,13.736,70.5,19.5
51,504.22,3240,0.85,11.7,33.8,504.55,3200,1.05,1.8 1,7.92,504.92,3200,13.804,70.5,19.5
,505.29,3160,1.45,17.8,39.8,505.63,3160,1.50,2.49, 10.48,506.01,3160,13.804,70.5,19.5
,506.36,3120,1.55,18.7,39.8,506.75,3120,1.55,2.58, 9.72,507.10,3080,13.804,70.5,19.5
,507.48,3040,1.10,13.5,39.8,507.83,3080,1.80,3.44, 14.51,508.17,3040,13.804,70.5,19.5
,508.53,2760,0.75,6.1,23.3,508.88,2360,0.75,1.98,6 .18,509.24,2440,13.804,72.0,19.5
,509.64,2440,2.10,20.4,36.8,509.96,2400,2.20,3.70, 11.59,510.30,2400,13.804,72.0,19.5
,510.65,2400,2.70,25.6,36.0,511.00,2400,3.00,5.25, 16.11,511.32,2400,13.872,72.0,19.5
,511.64,2400,3.75,29.9,33.8,511.98,2400,4.05,7.31, 22.15,512.32,2400,13.804,72.0,19.5
,512.65,2440,4.35,31.7,32.3,513.03,2440,4.40,7.65, 23.68,513.38,2440,13.804,72.0,19.5
,513.71,2440,4.45,32.1,32.3,514.05,2440,4.00,6.36, 18.06,514.40,2440,13.804,72.0,19.5
,514.78,2440,2.40,21.3,36.8,515.15,2440,2.30,3.78, 12.01,515.48,2440,13.872,72.0,19.5
,515.84,2440,2.15,19.5,36.8,516.15,2440,2.10,3.53, 11.04,516.49,2400,13.872,72.0,19.5
,516.84,2400,2.00,18.7,36.8,517.19,2400,2.00,3.44, 10.42,517.55,2400,13.872,72.0,19.5
,517.91,2400,1.90,17.4,36.8,518.29,2360,1.90,3.27, 9.86,518.62,2360,13.804,72.0,19.5
,518.98,2360,1.85,16.9,36.8,519.31,2360,1.85,3.10, 9.72,519.70,2360,13.804,72.0,19.5
,520.05,2360,2.35,21.7,36.8,520.44,2360,2.60,4.56, 13.89,520.76,2360,13.804,72.0,19.5
I dont know how to attach a file so I included some of the log file. If anyone can tell me how to attach a file I will do it.
Fom what I can see the mass air flow at idle is a little high 4.23 t0 4.31. The maximum air flow is 104.23 which seems ok for a 125 bhp engine.
Also the throttle angle is going from 8.7 degrees min to 83.3 degrees maximum (8.7 is a bit big for idle and 83.3 is a bit small for full throttle.
There were some when I started looking last week but after clearing them nothing has come back.
Any ideas what might still be causing the idle problems or what I should try next?
Regards
Tom
I did some logging with the VAG-Com during the weekend. I did the full thottle test of the MAF to check its operation. The following is the log file for blocks 1, 2 and 3. I had cleaned the MAF before doing the test.
Monday,30,October,2006,16:15:27
8D0 907 557 C,,1.8L R4/5V MOTR HS D08,
,Group A:,'001,,,,Group B:,'002,,,,Group C:,'003
,,Engine RPM,Engine load,Throttle angle,Ignition timing,,Engine RPM,Engine load,Inj. period,Mass air flow,,Engine RPM,Battery voltage,Coolant temp -G62,Intake air temp
,TIME, 820..900, 0.85..2.50, 0..5,12deg BDTC,TIME, 820..900, 0.85..2.50 , 2.0..5.0, 2.0..4.0,TIME, 820..900,10.0..14.5, 80..105,19.5=>see lbl file
Marker,STAMP, /min, ms,°, °ATDC,STAMP, /min, ms, ms, g/s,STAMP, /min, V,°C,°C
,140.91,1640,3.30,20.8,26.3,141.22,2000,1.75,2.32, 2.29,141.57,1680,13.940,64.5,19.5
,141.89,1320,1.05,6.9,18.0,142.22,1080,1.45,2.49,4 .65,142.58,800,13.940,64.5,19.5
,142.98,880,2.70,4.8,12.8,143.34,920,1.75,3.44,2.5 7,143.64,760,13.940,64.5,19.5
,143.99,640,2.00,9.1,20.3,144.30,680,2.55,4.82,4.3 1,144.68,800,14.008,64.5,19.5
,145.02,800,1.85,5.2,17.3,145.39,720,1.80,3.61,3.2 6,145.73,560,13.872,64.5,19.5
,146.12,800,2.85,3.5,18.8,146.45,880,1.90,3.44,3.0 6,146.85,720,13.940,64.5,19.5
,147.19,720,2.20,7.4,21.8,147.54,760,2.15,3.44,3.4 0,147.89,760,13.940,64.5,19.5
,148.27,680,2.20,9.1,20.3,148.62,760,2.30,3.61,3.6 1,149.01,800,13.940,64.5,19.5
,149.39,760,2.15,7.8,23.3,149.76,760,2.20,3.44,3.9 6,150.10,760,13.940,64.5,19.5
,150.39,800,2.20,8.2,22.5,150.71,840,2.15,3.53,3.8 9,151.06,840,13.940,64.5,19.5
,151.37,840,2.15,8.2,15.0,151.67,800,2.20,3.61,4.0 9,152.03,840,14.008,64.5,19.5
,152.34,840,2.20,8.7,13.5,152.65,840,2.15,3.70,4.0 9,152.95,800,13.940,64.5,19.5
50,476.65,840,2.25,8.7,12.8,476.99,840,2.25,3.78,4 .31,477.31,840,13.668,70.5,19.5
,477.65,840,2.30,8.7,14.3,478.03,840,2.30,3.70,4.3 1,478.40,840,13.736,70.5,19.5
,478.75,840,2.30,8.7,12.8,479.07,840,2.25,3.78,4.3 1,479.46,840,13.804,70.5,19.5
,479.79,840,2.30,8.7,12.8,480.13,840,2.25,3.61,4.2 3,480.44,840,13.804,70.5,19.5
,480.81,840,2.30,8.7,12.8,481.13,840,2.35,5.93,6.8 7,481.48,1040,13.804,70.5,19.5
,481.88,1600,2.45,8.2,27.0,482.23,1280,1.45,2.67,3 .82,482.55,960,13.736,70.5,19.5
,482.94,880,2.10,8.2,18.0,483.29,840,2.10,3.27,4.0 3,483.59,680,13.736,70.5,19.5
,484.00,560,2.85,11.7,12.8,484.37,680,3.40,6.02,4. 86,484.76,920,13.736,70.5,19.5
,485.14,1080,2.45,9.5,20.3,485.49,1080,1.85,2.67,3 .47,485.85,880,13.736,70.5,19.5
,486.14,640,2.00,10.0,21.0,486.45,480,3.55,8.00,8. 12,486.78,640,13.260,70.5,19.5
,487.08,840,3.40,10.0,3.8,487.43,1080,2.65,3.96,4. 37,487.75,1040,13.804,70.5,19.5
,488.07,920,2.00,8.2,20.3,488.39,800,2.30,4.47,5.9 7,488.68,880,13.736,70.5,19.5
,489.02,1440,3.70,18.7,21.0,489.36,1800,2.85,4.64, 9.79,489.73,1880,13.736,70.5,19.5
,490.06,1800,2.90,23.0,30.8,490.42,1800,3.55,7.31, 16.39,490.76,1920,13.736,70.5,19.5
,491.10,1840,5.60,35.6,19.5,491.45,1640,6.05,11.35 ,22.36,491.82,1800,13.736,70.5,19.5
,492.15,2200,6.55,48.6,21.8,492.53,2560,6.80,12.30 ,38.75,492.87,2800,13.736,70.5,19.5
,493.26,2520,0.80,5.6,15.0,493.60,1720,6.65,14.88, 30.34,493.91,2040,13.736,70.5,19.5
,494.29,2240,7.05,82.9,23.3,494.62,2400,7.20,13.76 ,39.51,494.97,2600,13.804,70.5,19.5
,495.34,2800,7.45,83.3,23.3,495.70,3040,7.60,14.79 ,50.34,496.06,3240,13.736,70.5,19.5
,496.46,3480,8.00,83.3,24.8,496.83,3720,8.20,16.25 ,69.09,497.21,4000,13.736,70.5,19.5
,497.60,4240,9.10,83.3,18.8,497.99,4520,9.00,17.20 ,89.65,498.33,4760,13.668,70.5,19.5
,498.70,5000,8.45,83.3,24.0,499.03,5200,8.35,16.25 ,93.47,499.39,5440,13.668,70.5,19.5
,499.74,5640,8.50,83.3,29.3,500.09,5880,8.45,16.60 ,104.23,500.45,6040,13.668,70.5,19.5
,500.79,6200,8.05,83.3,30.0,501.16,5840,0.80,0.95, 9.09,501.50,5160,13.804,70.5,19.5
,501.87,4120,3.20,44.3,24.0,502.30,4320,8.60,15.65 ,81.59,502.68,4440,13.736,70.5,19.5
,503.09,4560,8.65,65.1,18.8,503.47,4360,1.05,0.95, 6.53,503.84,3800,13.736,70.5,19.5
51,504.22,3240,0.85,11.7,33.8,504.55,3200,1.05,1.8 1,7.92,504.92,3200,13.804,70.5,19.5
,505.29,3160,1.45,17.8,39.8,505.63,3160,1.50,2.49, 10.48,506.01,3160,13.804,70.5,19.5
,506.36,3120,1.55,18.7,39.8,506.75,3120,1.55,2.58, 9.72,507.10,3080,13.804,70.5,19.5
,507.48,3040,1.10,13.5,39.8,507.83,3080,1.80,3.44, 14.51,508.17,3040,13.804,70.5,19.5
,508.53,2760,0.75,6.1,23.3,508.88,2360,0.75,1.98,6 .18,509.24,2440,13.804,72.0,19.5
,509.64,2440,2.10,20.4,36.8,509.96,2400,2.20,3.70, 11.59,510.30,2400,13.804,72.0,19.5
,510.65,2400,2.70,25.6,36.0,511.00,2400,3.00,5.25, 16.11,511.32,2400,13.872,72.0,19.5
,511.64,2400,3.75,29.9,33.8,511.98,2400,4.05,7.31, 22.15,512.32,2400,13.804,72.0,19.5
,512.65,2440,4.35,31.7,32.3,513.03,2440,4.40,7.65, 23.68,513.38,2440,13.804,72.0,19.5
,513.71,2440,4.45,32.1,32.3,514.05,2440,4.00,6.36, 18.06,514.40,2440,13.804,72.0,19.5
,514.78,2440,2.40,21.3,36.8,515.15,2440,2.30,3.78, 12.01,515.48,2440,13.872,72.0,19.5
,515.84,2440,2.15,19.5,36.8,516.15,2440,2.10,3.53, 11.04,516.49,2400,13.872,72.0,19.5
,516.84,2400,2.00,18.7,36.8,517.19,2400,2.00,3.44, 10.42,517.55,2400,13.872,72.0,19.5
,517.91,2400,1.90,17.4,36.8,518.29,2360,1.90,3.27, 9.86,518.62,2360,13.804,72.0,19.5
,518.98,2360,1.85,16.9,36.8,519.31,2360,1.85,3.10, 9.72,519.70,2360,13.804,72.0,19.5
,520.05,2360,2.35,21.7,36.8,520.44,2360,2.60,4.56, 13.89,520.76,2360,13.804,72.0,19.5
I dont know how to attach a file so I included some of the log file. If anyone can tell me how to attach a file I will do it.
Fom what I can see the mass air flow at idle is a little high 4.23 t0 4.31. The maximum air flow is 104.23 which seems ok for a 125 bhp engine.
Also the throttle angle is going from 8.7 degrees min to 83.3 degrees maximum (8.7 is a bit big for idle and 83.3 is a bit small for full throttle.
There were some when I started looking last week but after clearing them nothing has come back.
Any ideas what might still be causing the idle problems or what I should try next?
Regards
Tom
#14
11-10-2006, 09:19 PM
RE: unstable idle
Any ideas on this one? I have more logs if anyone wants to see them.
Regards
Tom
Regards
Tom
#15
01-01-2007, 08:24 PM
RE: unstable idle
Cheers guys for the suggestions. I eventually got around to cleaning the throttle body and doing a throttle body adaption afterwards and not the idle is totally stable. It quickly returns to around 1000 revs above idle and slowly returns to idle speed. It is also much smoother.
Regards
Tom
Regards
Tom
#16
02-05-2008, 10:11 AM
RE: unstable idle
ORIGINAL: kajwhite
I have the very same problem on my A4 but interestingly if the rear of the car is lower than the front (ie on a hill) there is no problem but if it is the reverse I struggle to even start the car. My helpful colleagues here suggest I get some real big front tyres to keep it permanently leaning back.
I have the very same problem on my A4 but interestingly if the rear of the car is lower than the front (ie on a hill) there is no problem but if it is the reverse I struggle to even start the car. My helpful colleagues here suggest I get some real big front tyres to keep it permanently leaning back.
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