Table of contents: Adjusting the gas drive ↓ Adjusting the cold start drive ↓ Checking and adjusting the idle… ↓
Adjusting the gas drive
Caution: The gas drive requires special care when installing. The slightest bend may lead to subsequent rupture during operation. Cables that have been bent must not be installed.
Press the gas pedal all the way down (full throttle) and fix the pedal in this position using a board.
Adjusting the cold start drive
All AUDI 80/90 diesels are equipped with a cold start device. The injection metering device inside the high-pressure fuel pump is set to an earlier position by 2.5° via a cable drive. This makes cold starting easier. During repair work, the drive cable should be connected as follows:
Install washer "1" on the drive cable. Insert the cable through the rubber bushing into the holder on the fuel pump. At the same time, insert the drive wire into the clamp bolt "3".
Install lock washer "2".
Set the drive lever to position 0 by pressing the lever all the way in the direction of the arrow.
Pull the drive wire and tighten it with clamping bolt "3".
Checking and adjusting the idle speed and maximum speed
Since diesel engines do not have an ignition system, a special tachometer (VDO) is required. It can be connected to the W terminal of the generator.
Warm up the engine to operating temperature. Engine oil temperature 60°C.
Connect the tachometer.
The cold starter rope should not stretch.
Electrical consumers (radio, light) must be turned off.
Check the idle speed: 1.6 l diesel – 875±25 rpm.; 1.9 l diesel and 1.6 l turbodiesel - 900±30 rpm. If necessary, set the idle speed with adjusting screw "1".
When turning to the right: the revolutions increase.
When turning to the left: the revs drop.
Caution: If the idle speed cannot be set below 900 rpm or 980 rpm because the stop is adjacent to the limiting bolt "3". Unlock the limiting bolt and unscrew it. Set the idle speed with the adjusting bolt "1", screw in the limiting bolt until it stops and lock it.
Checking the increase in RPM
Pull the cold start actuator out 1 click. The speed should increase by 60 rpm.
Pull the cold start actuator out completely. The speed should increase to 1050±50 rpm.
If the required values are not achieved, the cold start drive should be adjusted.
Caution: If the value of 1050 rpm is not achieved despite the correct installation of the cold start drive, loosen the stop screw, with the cold start drive pulled out, set the speed using the stop screw and lock it.
Checking the maximum number of revolutions
Give full throttle. Measure the speed: diesel 1.6 l: 5350±50 rpm; 1.6L turbodiesel: 5100±50 rpm; 1.9L diesel: 5050±100 rpm.
If necessary, loosen the lock nut of the adjusting screw -2 and set the maximum number of revolutions. Then tighten the lock nut.
Note: The protruding part of the adjusting screw -5 is protected by a cap.
The screw should not be displaced. If the screw is significantly displaced, the following problems may occur:
- 1. Screw is screwed in = protrusion is too large, idle speed is too high, not adjustable.
- 2. Screw out = protrusion too small, jerks when starting or accelerating due to too low RPM. If necessary, make a basic adjustment by removing the cap and locking the screw.
The protrusion is too small: Slowly turn the screw until the number of turns increases, then back off ½ turn.
The protrusion is too large: Loosen the screw until the RPM stops dropping. Then slowly turn the screw in until the RPM increases, then back off the screw ½ turn.
Lock the adjusting screw and close with a new cap.