I think maybe I found the vacumm leak or clog.. My ?? is, is this the problem for my high idle?
03-09-2004, 08:06 PM
#1
Banned
Thread Starter
Join Date: Feb 2004
Posts: 7,548
Likes: 0
Received 0 Likes
on
0 Posts
I think maybe I found the vacumm leak or clog.. My ?? is, is this the problem for my high idle?
Located at the bottom right [drivers side] of the throttle body plentium, there is a very small nipple that has a vac line connected to it. This vac line goes from the plentium to the lower right of the TB. It was very clogged, no air what so ever was getting through it at all. Could this be the problem for my 1800rpm idle or do I most likely have a vac leak somewhere else. I am asking only because the car cant be tested until tomorrow after i install a few parts.
03-10-2004, 05:48 AM
#4
AudiWorld Super User
Join Date: Aug 2002
Posts: 2,594
Likes: 0
Received 0 Likes
on
0 Posts
Re: High Idle
Bentley list 4 items to check in no particular order for a high Idle.
1. Idle Air Control (IAC) valve -N71- sticks, is hard to move or does not operate
- Failures because of contamination in the intake manifold; because of this, IAC valve rotary slide valve surface scratches possible.
- Cleaning with compressed air unsuccessful.
- When removed or disconnected, only limp home slot can be seen. The control edge lies on the opposite side.
- The limp home slot of IAC valve -N71- must not be widened by tools inserted from the outside.
- The visible surface of the rotary slide valve must not be machined mechanically.
- Check IAC valve Page 24-34 (internal resistance: 7-10 ohms)
2. Throttle Body (TB) faulty
- Air leak at stage 2 leads to incorrect learned values. DTC 01257 (IAC valve) can be stored, read DTC memory.
- Malfunction in the ECM or mass air flow sensor is unlikely.
- Difficult to recognize with On Board Diagnostic, since usually there is no constant air leak value.
-Perform basic setting of the engine Repair Group 01.
- Using "Read Measuring Value Block" function 08, display group 004, display fields 2 and 3, check whether specified values lie in the lower or upper limit range. If the values lie outside or very close to the tolerance limit, see Repair Group 01.
- Throttle Body can only be checked visually for sticking, e.g. after removal.
3. Throttle Position (TP) sensor -G69- and Closed Throttle Position (CTP) switch simultaneously faulty
No acceleration enrichment.
Throttle position sensor incorrectly adjusted, has tolerance problem and/or break in wiring on resistor area (misfiring/bucking, poor throttle response).
Throttle position sensor remains continuously on wide open throttle. (Fuel consumption too high)
- Read DTC memory and check "Read Measuring Value Block" function 08, display group 002 with VAG 1551 Repair Group 01. With continuous accelerator pedal movement/throttle opening this value must also increase continuously.
- Check wiring connector.
4. Engine Coolant Temperature (ECT) sensor -G62- out of tolerance
This results in a function of the oxygen sensor control. Engine too rich or too lean.
- Check resistance Repair Group 28.
- Check to see whether values displayed are realistic - "Read Measuring Value Block" function 08, display group 001, display field 2 Repair Group 01.
1. Idle Air Control (IAC) valve -N71- sticks, is hard to move or does not operate
- Failures because of contamination in the intake manifold; because of this, IAC valve rotary slide valve surface scratches possible.
- Cleaning with compressed air unsuccessful.
- When removed or disconnected, only limp home slot can be seen. The control edge lies on the opposite side.
- The limp home slot of IAC valve -N71- must not be widened by tools inserted from the outside.
- The visible surface of the rotary slide valve must not be machined mechanically.
- Check IAC valve Page 24-34 (internal resistance: 7-10 ohms)
2. Throttle Body (TB) faulty
- Air leak at stage 2 leads to incorrect learned values. DTC 01257 (IAC valve) can be stored, read DTC memory.
- Malfunction in the ECM or mass air flow sensor is unlikely.
- Difficult to recognize with On Board Diagnostic, since usually there is no constant air leak value.
-Perform basic setting of the engine Repair Group 01.
- Using "Read Measuring Value Block" function 08, display group 004, display fields 2 and 3, check whether specified values lie in the lower or upper limit range. If the values lie outside or very close to the tolerance limit, see Repair Group 01.
- Throttle Body can only be checked visually for sticking, e.g. after removal.
3. Throttle Position (TP) sensor -G69- and Closed Throttle Position (CTP) switch simultaneously faulty
No acceleration enrichment.
Throttle position sensor incorrectly adjusted, has tolerance problem and/or break in wiring on resistor area (misfiring/bucking, poor throttle response).
Throttle position sensor remains continuously on wide open throttle. (Fuel consumption too high)
- Read DTC memory and check "Read Measuring Value Block" function 08, display group 002 with VAG 1551 Repair Group 01. With continuous accelerator pedal movement/throttle opening this value must also increase continuously.
- Check wiring connector.
4. Engine Coolant Temperature (ECT) sensor -G62- out of tolerance
This results in a function of the oxygen sensor control. Engine too rich or too lean.
- Check resistance Repair Group 28.
- Check to see whether values displayed are realistic - "Read Measuring Value Block" function 08, display group 001, display field 2 Repair Group 01.
Thread
Thread Starter
Forum
Replies
Last Post
wahoo2.7T
A6 / S6 (C5 Platform) Discussion
5
02-03-2004 07:37 AM