S4 will not run
01-02-2008, 02:23 AM
#46
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John Speake is another great resource....
I keep thinking its the MAF causing an odd limp home feature causing the rich condition.... or a combo MAF-LH thing..... but you've checked all of those?
It does seem something is causing the injectors to fire too much.....but why....the new LH didn't help?? I can't think of anything in the fuel system that would fail and cause TOO much fuel..... Have you checked the dampers to see if they hold vacumm and don't squirt gas.....same for the pressure regulator.....but I thought when the regulator fails it just sends too much gas back to the tank......
I keep thinking its the MAF causing an odd limp home feature causing the rich condition.... or a combo MAF-LH thing..... but you've checked all of those?
It does seem something is causing the injectors to fire too much.....but why....the new LH didn't help?? I can't think of anything in the fuel system that would fail and cause TOO much fuel..... Have you checked the dampers to see if they hold vacumm and don't squirt gas.....same for the pressure regulator.....but I thought when the regulator fails it just sends too much gas back to the tank......
01-02-2008, 06:03 AM
#47
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This certainly is a bit of a mystery. Have you tried unplugging the MAF ? This will force the LH into a limp home, fixed injector pulse pattern, regardless of other inputs.
Are you quite sure that the code plug is inserted into the cable form socket ?
How was the car running before it went to the paint shop ?
Are you quite sure that the code plug is inserted into the cable form socket ?
How was the car running before it went to the paint shop ?
01-02-2008, 06:34 AM
#48
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This certainly is a bit of a mystery. Have you tried unplugging the MAF ? This will force the LH into a limp home, fixed injector pulse pattern, regardless of other inputs.
Are you quite sure that the code plug is inserted into the cable form socket ?
How was the car running before it went to the paint shop ?
Are you quite sure that the code plug is inserted into the cable form socket ?
How was the car running before it went to the paint shop ?
I have followed the procedure outlined here http://www.electronikrepair.com/
Measured the pot (300 ohm)
MAF hot wire 4.1 ohm
WOT OK
Idle position switch OK
Temp II (~2K ohm @ 30C)???
ECU ground 0 ohm
All above tests performed from the LH connector!
All fuel dampers OK (no vac leak)
The only thing I didn't test yet is the fuel pressure. I'm getting a tester tomorrow. The car was running excellent before went to the body shop. It just had a major service < 500 Km ago. I did remove the MAF but no difference.
The interesting thing is when I plug my ECU back, the car starts and idles (bet rough) but wont respond to throttle (or dies).
The new ECU the car will start but will not hold idle unless I use the accelerator, but will respond to throttle
Thank you guys for your help. Great community. I appreciate it
Last edited by touay001; 01-02-2008 at 06:38 AM. Reason: More info
01-02-2008, 01:20 PM
#50
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At present I can't think of a likely cause other than the code plug. You can check for the correct link positions from Page 24-221 in Vol 1A of the WS manual.
01-02-2008, 07:26 PM
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Hi Aryan,
The car was there for 9 weeks. I added extra 20L of fuel during the trouble shooting.
Hi John,
The code plug seems to be OK. The option is for none cat/automatic.
01-10-2008, 08:27 PM
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01-11-2008, 05:27 PM
#57
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So it was 2 faulty LH's?
If so, that makes me suspicious.. what condition is your alternator in? If its suffering voltage spikes, from what I've read that may be killing the LH?
01-11-2008, 08:00 PM
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I don't think there is something wrong with the alternator (otherwise the current LH would have been zapped as well). The problem with my LH was that the shop jump starting the car with high output battery booster. Now I need to put the car back together and enjoy it
