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Jetta L4-1781cc 1.8L SOHC (ACC) Can (1995)

Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Idle Speed > System Information > Technical Service Bulletins > Page 1551

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Idle Speed: Testing and Inspection

Idle speed, checking 

Note: 

^  Idle speed is not adjustable.
^  The fuel mixture (CO content) is regulated by Oxygen Sensor control. Malfunctions are detected by the On Board Diagnostic part of the

Mono-Motronic Engine Control Module (ECM) and stored in the Diagnostic Trouble Code (DTC) Memory.

 
 
Test conditions 

^  No malfunctions stored in Diagnostic Trouble Code (DTC) Memory (Check and erase DTC Memory)   See: Powertrain Management/Computers

and Control Systems/Testing and Inspection

^  Accelerator Pedal cable adjustment OK
^  Exhaust system free of leaks
^  Engine oil temperature at least 80°C (176°F)
^  All electrical consumers switched OFF (radiator Coolant Fan must not run during test)
^  A/C switched OFF
^  Ignition timing OK.   See: Ignition Timing/Testing and Inspection
^  Oxygen Sensor connected

 
 

Connect VAG 1367 engine tester using VAG 1367/8 inductive pickup.

Start engine and run at idle.

Check idle speed:
Specification: 750 to 1000 RPM 

If the idle speed is not within the specified range:

Check Throttle Position (TP) Actuator   See: Powertrain Management/Computers and Control Systems/Throttle Position Actuator/Testing and
Inspection

Vehicles with CO tap tube

Connect VAG 1363A CO Tester to CO tap tube with VAG 1363/3 adapter.

Check idle speed and exhaust CO content:
^  CO content: 0.2 to 1.2% by volume 

 
 

Technical Data

Engine, Cooling and Exhaust > Engine > Tune-up and Engine Performance Checks > Idle Speed > System Information > Technical Service Bulletins > Page 1551

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