Engine Testing, Adjustment
Engine testing, adjustment
Test and Adjustment Data:
Current at Actuator with Ignition Switched On:
Ignition Point (TSZ) US Version:
Special Tools:
Commercially Available Testers:
Shop Made Tool:
Note:
Test and adjust lambda control with a lambda control tester.
The lambda control and the idle speed emissions level must not be tested when the engine is very hot, e.g. immediately after driving sharply or after measuring engine output on the dynamometer.
Testing, adjusting
1 Complete measurement sheet.
2 Switch off air conditioning or automatic climate control. Move selector lever into position "P".
3 Read out DTC memory. Note: Not available on model year 1984-1986.
4 Connect testers:
oil remote thermometer (018)124 589 07 21 00
lambda control tester (012)
twin socket (031)
trigger clamp (011)
exhaust probe (005)126 589 11 63 00
CO measuring instrument (006)
engine tester with oscilloscope (030)
multimeter (003)
test cable (033)102 589 04 63 00.
5 Position extraction device (014) at exhaust tail pipe.
6 Check engine coolant level, adjust to correct level.
7 Check engine oil level, pay attention to condition of oil (visual inspection).
8 Take off air cleaner.
9 Check ease of movement and condition of throttle control linkage and throttle valve. Grease all bearing points and ball sockets.
10 Check fulcrum lever, adjust. Check whether the roller (15) in the fulcrum lever (13) is resting free of tension against end stop. Adjust fulcrum lever (13) with the connecting rod (2), if necessary, so that the roller (15) is resting free of tension against end stop.
11 Idle stop.
Check whether the throttle valve is resting against idle stop. Disconnect connecting rod (2) for this step. Adjust throttle control.
Engines with cruise control only. Check whether the actuator is resting against idle stop of cruise control by pressing the lever of the actuator clockwise against idle stop at cruise control. When attaching the connecting rod (21), ensure that the lever of the actuator is lifted approx. 1 mm off the idle stop at the cruise control. Adjust tie rod, if necessary. Adjust throttle control.
12 Check wide open throttle stop from the accelerator pedal, adjust.
13 Voltages
Test (battery and ignition coil):
No-load voltage
Connect voltmeter to the battery, paying attention to the polarity, and take reading of voltage. Specification: 12.2 volts.
Ignition coil
Switch on ignition with engine not running. Test the voltage terminal 15 to ground at contact 5 of diagnostic connector. Specification: battery voltage
Test difference in voltage between terminal 15 and terminal 1 at contacts 5 and 4 of diagnostic connector. Specification: 0 volts
If the specified values are not reached, test ignition system.
14 Test current at actuator with ignition switched on by detaching coupling at actuator and inserting test cable 102 589 004 63 DO into the circuit. Connect multimeter, set to mA (see table).
On Std. version, detach connector at engine coolant temperature sensor.
If the specified values are not reached, test electrical components.
15 Test ignition point and vacuum advance (see table). For TSZ version, test centrifugal advance.
If the specified values are not reached, test ignition system.
16 Check oil level in automatic transmission.
17 Test deceleration shut-off (engine coolant temperature >50°C).
Hold engine speed at a constant >3000/min. Operate microswitch by hand; this must cause the engine to saw.
Electrical test of deceleration shutoff. Testing Electrical Components of CFI System
Check fuel pressures and internal leaktightness if necessary. Testing and Inspection
18 Run engine to raise oil temperature to approx. 80°C.
19 Analyze oscilloscope image.
20 Check intake system for leaks. Fit "shop-made intake pipe" to fuel distributor before spraying. Spray all sealing points with ISO octane DIN 51 756 or cleaning petroleum. CO rise <2%.
WARNING! Do not use commercially available fuel for spraying (risk of harmful vapors). Pay attention to fire hazard and do not spray onto glowing parts or parts of the ignition system.
21 Check function of exhaust gas recirculation valve.
Detach both vacuum lines at the exhaust gas recirculation valve (60). Connect tester to EGR valve (connection A, red) and pressurize with vacuum. If there is not a clear deterioration in engine running, replace exhaust gas recirculation valve. Check valve actuation, if necessary.
22 Install air cleaner.
23 Test idle speed (see table).
Note: The idle speed of engines fitted with electronic idle speed control cannot be adjusted. If the idle speed varies, test electronic idle speed control. Idle Speed
Engine 102.961 without idle speed control:
Adjust engine speed with the idle air screw (arrow).
Check idle stop at throttle body assembly when performing this step.
24 Test idle emissions level (see table). Measured at exhaust tail pipe. Setting idle emissions level, see step 25.
25 Test lambda control (see table).
Note: The readout must fluctuate during the measurement. If a constant value is indicated, there is a fault in the lambda control, e.g. exhaust sensor disconnected.
See "Testing electrical components of CFI system" for trouble diagnosis. Testing Electrical Components of CFI System
Measuring voltage with multimeter or lambda control tester (12 volt position) at contact 3 of diagnosis socket to ground.
Test value: 2.1-4.8 volts
Switch off all auxiliary components.
Detach oxygen sensor signal plug connection (G3/2x2). Take reading of control value (e.g. 3.3 volts). Readout must not fluctuate.
Plug together heated oxygen sensor signal plug connection (G3/2x2) - readout fluctuates. Test value must vary not more than ±0.8 volts from the control value. Variation >0.8 volts, set control value.
26 Adjust idle emissions level and lambda control (see table).
Measuring point (arrow) for Std. KAT (open-loop), upstream of catalytic converter.
Remove anti-tamper plug (4) with the extractor.
Insert a screwdriver (1) through the recess on the top of the air cleaner onto the adjusting device (2). Press the adjusting device down with the screwdriver against the spring force, turn it slightly until the hexagon head (3) engages in the mixture regulating screw (61).
Turning to the left = leaner - on/off ratio/ voltage rises.
Turning to the right = richer - on/off ratio/ voltage drops.
After each adjustment, blip throttle slightly; readjust if necessary.
After adjusting, insert a blue anti-tamper plug (4), Part No.000 997 59 86, with the inserting drift.
27 Check smooth engine running by moving selector lever into Drive mode, switching on air conditioning/automatic climate control, turning power steering to full lock. The engine must continue to run smoothly.