07.2-100 Testing, adjusting idle speed and
special exhaust emissions test (ASU)
Operation no. of operation texts and work units or standard texts and flat rates 07-2053 or 00-7600 |
Testers (see ill.) | connect. |
Accelerator control linkage | check for operation and ease of movement. |
Firing point | test, adjust. |
Engine oil temperature | raise to approx. 80 °C. |
Idle speed | check. |
Exhaust emissions level | test, adjust. |
Lambda control | test, adjust. |
Smooth engine running | check, switch on all ancillaries. |
Test and adjusting data
Firing point
Engine/ | Ignition control unit EZL part no. | Engine speed in rpm | Firing point in ° CA before TDC 1) | ||
Resistance trimming plug position | w/o vacuum | with vacuum | |||
102.922 | 004 545 79 32 | 3200 | S | 22-26 | 38-42 |
102.924 | 004 545 81 32 | N | 15-19 | ||
KAT/RÜF | 006 545 40 32 006 545 41 32 | Idling | S and N | 11-15 | 11-15 |
006 545 52 322) | 3200 | S | 19-23 | 38-42 | |
006 545 53 322) | N | 14-18 | |||
Idling | S and N | 11-15 | 11-15 | ||
1) If readout varies, test ignition system (15-540).
2) Ignition control unit with fault control if fault exists at throttle valve actuator.
Idle speed, lambda control
Engine | Version | Idling speed in rpm | Idle emissions level | Lambda control |
102.922 | RÜF | 700-800 | 1.50.5 | - |
102.924 | KAT | 1) | 5010 | |
1) For special exhaust emissions test (ASU) 0.5 %
Special tools
Commercial testers
Revolution counter, CO tester, stroboscope | |
Digital tester (engine speed, dwell angle, ignition angle) | e. g. Bosch |
Lambda control tester | e. g. Hermann, |
Note
Do not detach crankcase breather for adjusting idle speed!
Idle speed must not be adjusted when the engine is hot, e. g. immediately after driving the car sharply or after measuring engine output on the performance tester.
Testing, adjusting
1 Connect testers:
Digital tester
CO tester
Remote oil thermometer
Lambda control tester
2 Switch off air conditioning or automatic climate control, move selector lever into position "P".
3 Test firing point with vacuum at idling speed. (If variations exist, perform test routine 15-540).
4 Raise engine oil temperature to approx.
80 °C.
5 Test idling speed (if variation from specified speed exists, perform additionally test steps as shown in troubleshooting table (07.2-114, Section G)).
6 Test idle exhaust emissions and lambda control, respectively, adjust.
RÜF cars
Test idle exhaust emissions level at tail pipe.
CAT cars
Test lambda control.
This is done by setting selector switch on lambda control tester to 100 % .
Take reading in idle control range. Pointer should swing equally to both sides of the 50 % setting.
Adjust idle exhaust emissions level or lambda control, respectively.
This is done by removing the security plug with a puller (028) and adjusting the idle exhaust emissions level or lambda control by turning the mixture adjusting screw (arrow).
(If the reading varies from the specified level, perform additionally test steps 1 and 8 (07.2-114, Section "I")).
After setting, press in new security plug (blue) with fitting mandrel (029).
7 Move selector lever into drive position, switch on air conditioning or automatic climate control. Turn power steering to full lock. Engine must run smoothly.