ABS AUDI A8 1998 D2 / 1.G ATQ Engine Motronic Injection System Servicing Workshop Manual
Page 4 of 78
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Rules of cleanliness
 
      When working on the fuel supply or fuel injection 
systems, the following "6 rules of cleanliness" 
should be carefully observed:  
     
Thoroughly clean all connections and the 
surrounding area before disconnecting. 
     Place parts that have been removed on a clean 
surface and cover. Use lint-free cloths only! 
     Carefully cover opened components or seal 
them if repairs are not carried out immediately. 
     Only install clean components: Only unpack 
replacement parts immediately prior to 
installation. Do not use parts that have been 
stored loose (in tool boxes etc.) 
     When the system is open: Do not work with 
compressed air if it can be avoided. Do not 
move vehicle unless absolutely necessary. 
     Disconnected electrical harness connectors: 
Protect from dirt and moisture. Be sure harness 
connector is dry before connecting. 
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Page 14 of 78
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Note:  
In order to assure sufficiently secure fitting, switches must not be installed 
more than once. 
Adjusting switch: 
 Repair Manual, Brake System, ABS, ABS/EDL, Repair Group 46
    Fig. 9  Component location Brake Light Switch -F- and Brake 
Vacuum Vent Valve Switch For Cruise Control/Diesel Fuel 
Injection, Clutch Vacuum Vent Valve Switch -F36- 
1 - Clip
2 - Brake Light Switch -F-, Brake Vacuum Vent Valve Switch For Cruise 
Control/Diesel Fuel Injection -F47- 
3 - Clutch vacuum vent valve switch -F36-
    
Secondary Air Injection (AIR) Pump Relay -J299- (arrow) in 3-pin relay 
carrier in E-box, plenum chamber.  Fig. 10  Component location for Secondary Air Injection (AIR) 
Pump Relay -J299- 
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Intake air system, checking for leaks 
(unmetered air)
 
     
Special tools and equipment  
    
Notes: 
VAS5051 with VAG5051/1
   orVAG1551 with VAG1551/3BEngine leak detection spray G 001 800 A1The negative pressure in the intake system sucks in the leak detection 
spray with the unmetered air. Leak detection spray decreases ignition 
quality and performance of the fuel mixture. This causes a reduction in 
engine speed and a sharp increase of CO content. It is absolutely necessary to follow the safety precautions listed on the 
can. 
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