14-100 Testing EGR
 
 

 
 
For complaints such as: Very poor engine performance, black or blue smoke.
 
 

 
 
Test conditions:
Throttle linkage correctly adjusted, connect tachometer, engine at operating tempera­ture, run engine at idle (750 ± 100/min), steering in straightahead position, air condi­tioning turned off, selector lever of automatic transmission in position "P".
Exhaust gas recirculation (EGR).
 
 
Tested:
 
 

 
 
Special tools
 
 

 
 
Tester 0—100 mbar for vacuum and gauge pressure
om617 - 0349-1.jpg
201 589 13 21 00
 
 
1DO4-12O99
 
 

 
 
Clamp
om617 - 0349-2.jpg
000 589 40 37 00
 
 

 
 
Test cable
om617 - 0349-3.jpg
11004-11172
102 589 04 63 00
 
 

 
 
Adjusting roller
916 589 00 21 00
 
 

 
 
Conventional tools
 
 

 
 
Digital tester
e.g. Bosch, MOT 001.03 e.g. Sun, DIT9000 e.g. Sun, 1019
 
 

 
 
Multimeter
e.g. Sun, DMM—5
 
 

 
 
Self-made test connection
 
 

 
 
Distributor
om617 - 0349-4.jpg
117 078 01 45
 
 
a Vacuum line 4 x 1 x 400 mm
 
 
1074-8889
 
 

 
 
Test line 4 x 1 x 400 mm
 
 

 
 
14.8-100/1 USA F3
 
 

 
                 

 

         
 

 
 
A. (©)model year 1980
 
 

 
 
om617 - 0350-1.jpg
 
 

 
 
Operational diagram vacuum line layout
1    Intake manifold
31    Exhaust manifold
36   Thermovalve 1 7 °C/63 °F
60   Exhaust gas recirculation valve (EGR)
61    Corrugated tubing
62   Orifice
63   Orifice
64a Switchover valve, idle speed shutoff — EGR 64bSwitchover valve, full load shutoff — EGR
65    Vacuum control valve
66    Injection pump
67    Vacuum pump
68    Guide lever with cam
a      Automatic transmission
b      Vent to passenger compartment
c      Brake unit
bk =   black
br =   brown
gr =   green
pu =   purple
re =   red
wh =   white
 
 

 
 
14.8-100/2 USA 1980 F 3
 
 

 
         

 

         
 

 
 
           
 
Testing EGR
Connect vacuum tester between EGR valve (60) and switchover valve (64b) to vacuum line (white/purple/brown). At idle, with throttle linkage at idle stop, no vacuum should be indi­cated. Advance control linkage until free travel of free travel rod is eliminated (do not pull on stop lever). Vacuum should now amount to 350-500 mbar.
 
 
Vacuum nominal value of 350— 500 mbar is attained.
Vacuum nominal value is not attained or exceeded.
 
 

...............^

 
 

 
           
om617 - 0351-1.jpg
 
 
om617 - 0351-2.jpg
 
 
om617 - 0351-3.jpg
Check vacuum lines
Check all vacuum lines for control of EGR system and of automatic transmis­sion according to operational diagram vacuum line layout for correct connec­tion and leaks. Blow through orifice (62) at vacuum tapping point.
Check black vent line (arrow) from vacuum control valve to passenger com­partment for free passage.
 
 
om617 - 0351-4.jpg
 
 
Check thermovalve 40 °C/104 °F (36, color code blue)
Pull off vacuum line (white/purple/ brown) on diagonal connection of thermo­valve.
om617 - 0351-5.jpg
 
 
Check vacuum line (white/brown) on dis­tributor (a) and check for passage. If there is no passage, replace thermovalve.
 
 

 
 
14.8-100/3 USA 1980 F3
 
 

 
         

 

         
 

 
 
om617 - 0352-1.jpg
When thermovalve is cooling down, thermo-valve should have no passage at tempera­tures below 7 °C/45 °F.
 
 
Check switchover valve (64a)
Pull connection (arrow) of vacuum line (white/purple/brown) from switchover valve.
Connect vacuum tester to free connection of switchover valve and connect with pulled off vacuum line. Vacuum readout approx. 350—500 mbar (regulating linkage at idle speed stop).
om617 - 0352-2.jpg
 
 
Leak test
Disconnect distributor of white/purple/ brown vacuum line. Vacuum should remain constant for approx. 2 minutes.
If vacuum drops, replace switchover valve.
 
 
If vacuum remains constant, check switch­over:
For this purpose, remove clamp, pull off connecting hose between the two switch­over valves and bridge free travel on free travel rod.
Vacuum should distinctly drop. If vacuum is not dropping, replace switchover valve.
om617 - 0352-3.jpg
 
 
Checking switchover valve (64b)
Pull off vacuum line (white) on switch­over valve (64b). Pull off vacuum line (white/purple/brown) on switchover valve (64a). Connect vacuum tester to free con­nection of switchover valve (64b) and connect with pulled off vacuum line (white/purple/brown). Vacuum readout 350-500 mbar.
om617 - 0352-4.jpg
 
 

 
 
14.8-100/4 USA 1980 F 3
 
 

 
         

 

             
 

 
 
om617 - 0353-1.jpg
Leak test
For this purpose, disconnect distributor of vacuum line (white/purple/brown). Vacuum should remain constant for approx. 2 minutes.
If vacuum drops, replace switchover valve.
If vacuum remains constant, check switch­over:
For this purpose, remove clamp and pull off vacuum line (white/purple/brown) on switchover valve (64b). Switch over switch­over valve with screwdriver. Vacuum should drop to "0".
If vacuum is not dropping to "0", replace switchover valve.
om617 - 0353-2.jpg
 
 
om617 - 0353-3.jpg
 
 
om617 - 0353-4.jpg
 
 
Checking EGR valve (60)
Switch over switchover valve (64a) by bridging free travel "L" on free travel rod. Pull off vacuum line on EGR valve and plug on again.
 
 
EGR valve should audibly close.
EGR valve not closing.
 
 
om617 - 0353-5.jpg
Replace EGR valve (60).
om617 - 0353-6.jpg
 
 
om617 - 0353-7.jpg
 
 
om617 - 0353-8.jpg
 
 

 
 
14.8-100/5 USA 1980 F 3
 
 

 
             

 

           
 

 
 
Checking vacuum control
Connect vacuum tester to vacuum line between EGR valve (60) and switchover valve (64b). Increase idle speed to 1000 ± 10/min by operat­ing regulating linkage (do not pull on stop lever)
om617 - 0354-1.jpg
 
 
Vacuum amounts to 320-350 mbar.
Vacuum is below or above specified value.
 
 
om617 - 0354-2.jpg
om617 - 0354-3.jpg
 
 
om617 - 0354-4.jpg
 
 
Check orifice (63)
Check if orifice is open and blow through, if required.
 
 
Change orifice (63)
If the vacuum is not attained or is exceed­ed, install the next larger size orifice, if the vacuum is too high and the next smaller orifice if the vacuum is too low.
If the correct vacuum is not attained by the installation of another orifice, replace vacuum control valve (65).
 
 

 
 
End of test
 
 

 
 
14.8-100/6 USA 1980 F 3
 
 

 
           

 

         
 

 
 
B. <@> starting model year 1981
 
 

 
 
om617 - 0355-1.jpg
 
 

 
 
Operational diagram, vacuum line layout
1    Intake manifold
31   Exhaust manifold
36   Thermovalve 40 °C/104°F
60   Exhaust gas recirculation valve (EGR)
61   Corrugated tubing
62   Orifice
63   Orifice
64a Switchover valve, idle speed shutoff — EGR 64bSwitchover valve, full throttle shutoff — EGR 65 Vacuum control valve
66    Injection pump
67    Vacuum pump
68    Guide lever with cam
69    Valve plate
71    Central plug
72    Vacuum damper
a      Vent to passenger compartment
b      Automatic transmission
c      Brake unit
       
 
bk
= black
 
 
br
= brown
 
 
gr
= green
 
 
pu
= purple
 
 
re
= red
 
 
wh
= white
 
       
 
 

 
 
Checkup
 
 

 
 
Note: At begin of test, yellow orifice (63) should be installed.
 
 

 
 
14.8-100/7 USA starting 1981 F3
 
 

 
         

 

           
 

 
 
Testing EGR
Connect vacuum tester between EGR valve (60) and straight connection of thermovalve (36). At idle, with throttle linkage at idle stop, no vacuum should be indicated. Advance control linkage until free travel of free travel rod is eliminated (do not pull on stop lever). The vacuum should now amount to 350-500 mbar.
om617 - 0356-1.jpg
 
 
Idle, no vacuum present.
Vacuum of 350— 500 mbar is attained.
Vacuum present. Vacuum not attained or exceeded.
 
 
om617 - 0356-2.jpg
 
 
om617 - 0356-3.jpg
om617 - 0356-4.jpg
 
 
Check vacuum lines
Check all vacuum lines for control of EGR and automatic transmission accord­ing to operating diagram vacuum line layout for correct connection and leaks. Blow through orifice (62) in vacuum tapping point, if required.
Check black vent line (arrow) from vacuum control valve to passenger com­partment for free passage.
 
 
om617 - 0356-5.jpg
 
 
Check thermovalve 40 °C/104 °F (36, color code blue)
Pull off white/brown vacuum line on diagonal connection of thermovalve.
Pull off white/purple/brown vacuum line on EGR valve and blow through.
If there is no passage, remove thermovalve.
om617 - 0356-6.jpg
 
 

 
 
14.8-100/8 USA starting 1981 F3
 
 

 
           

 

         
 

 
 
om617 - 0357-1.jpg
Check switchover valve (64a)
Pull central plug (71) from valve plate (69). Connect test line between tapping point (black orifice, arrow) on vacuum line for brake unit and valve plate connec­tion (1). Connect vacuum tester to connec­tion (3). Close connection (2).
Vacuum readout at switchover:
Idle speed (throttle linkage at idle speed
stop) "0" mbar.
Bridge idle speed (do not pull on stop
lever) approx. 700-800 mbar.
Leak test:
Let throttle linkage return to idle speed
stop, stop engine.
Vacuum should remain constant for
approx. 2 minutes.
Pull closing cap from connection (2).
Bridge idle speed.
Vacuum should drop to "0".
If test values are not attained: Replace switchover valve (64a).
om617 - 0357-2.jpg
 
 
om617 - 0357-3.jpg
 
 
Check switchover valve (64b)
Pull central plug (71) from valve plate (69). Connect test line between tapping point (black orifice, arrow) on vacuum line brake unit and valve plate connection (1). Connect vacuum tester to connection (2).
Close connection (3), start engine.
Vacuum readout:
Idle speed (regulating linkage on idle
speed stop) approx. 700—800 mbar.
Leak test:
Disconnect tapping point for test line (arrow). Stop engine, vacuum should remain constant for approx. 2 minutes.
om617 - 0357-4.jpg
 
 

 
 
14.8-100/9 USA starting 1981 F3
 
 

 
         

 

           
 

 
 
om617 - 0358-1.jpg
Vacuum readout at switchover: Throttle linkage at full throttle stop, vacuum should remain constant. Let throttle linkage return to idle speed stop and pull off test line.
Vacuum should drop to "0".
If test values are not attained, renew switchover valve (64b).
om617 - 0358-2.jpg
 
 
om617 - 0358-3.jpg
 
 
om617 - 0358-4.jpg
 
 
Checking EGR valve (60)
Start engine. Operate switchover valve (64a) by eliminating free travel "L" on free travel rod. Pull off vacuum line on EGR valve and plug-on again.
 
 
EGR valve should audibly close.
EGR valve not closing.
 
 
om617 - 0358-5.jpg
om617 - 0358-6.jpg
 
 
Replace EGR valve (60).
 
 
om617 - 0358-7.jpg
 
 

 
 
14.8-100/10 USA starting 1981 F3
 
 

 
           

 

       
 

 
 
Note: Check adjustment of vacuum control valve prior to test.
om617 - 0359-1.jpg
 
 
om617 - 0359-2.jpg
 
 
om617 - 0359-3.jpg
 
 
om617 - 0359-4.jpg
 
 

 
 
14.8-100/11 USA starting 1981 F3
 
 

 
       

 

           
 

 
 
C.
model year 1984 California
 
 

 
 
om617 - 0360-1.jpg
 
 

 
 
Function diagram vacuum line installation
1    Intake manifold
2   Exhaust gas turbocharger 50   EGR-valve
63   Orifice 0.5 mm
64   Control rod travel indicator
65   Vacuum control valve
66   Injection pump
67   Vacuum pump
71   Circulating air safety valve
72   Vacuum damper 80   Control unit
81     Switchover valve
82     Rpm sensor
83    Temperature sensor coolant (NTC)
84     Pressure converter
85     Vent filter
140    Check valve, model 123
140a   Check valve, model 126
a         Vent line to passenger compartment
b         To automatic transmission
c         Remaining consumers
bk = black bl = blue br = brown gr = green pu = purple re = red wh = white
 
 

 
 
14.8-100/12 USA 1984 California F 3
 
 

 
           

 

         
 

 
 
om617 - 0361-1.jpg
 
 

 
 
Electric wiring diagram
64   Control rod travel indicator
80   Control unit
81   Switchover valve
82   Rpm sensor
83   Temperature sensor
84   Pressure converter
85   Overvoltage protection
86   Compensating plug
M1    Main ground behind instrument cluster
M5   Ground, engine
a      To revolution counter
b      To fuse capsule, terminal 15
c      To supporting lug, terminal 30
bl = blue br = brown ge = yellow gn = green it = red sw = black
 
 

 
 
14.8-100/13 USA 1984 California F 3
 
 

 
         

 

             
 

 
 
Short test
om617 - 0362-1.jpg
 
 
Test EGR-valve (60) with engine stopped
Activate EGR-valve with approx. 300 mbar vacu­um. Pull off vacuum line.
 
 
EGR-valve closes audibly
not closing
om617 - 0362-2.jpg
 
 
om617 - 0362-3.jpg
Renew EGR-valve.
 
 
om617 - 0362-4.jpg
 
 
Testing voltage at pressure converter (84)
Engine stopped, ignition switched on. Pull plug from pressure converter and connect with multi­meter (arrow), push button "V=" and read no­minal value 12 V.
 
 
Readout in order
not in order
om617 - 0362-5.jpg
 
 
om617 - 0362-6.jpg

 
 
Test overvoltage protection and electric activation according to wiring diagram.
 
 
om617 - 0362-7.jpg
 
 

 
 
14.8-100/14 USA 1984 California F3
 
 

 
             

 

           
 

 
 
Testing vacuum control
Connect vacuum tester with Y-distributor to EGR-valve (60).
Read vacuum values at the following engine speeds:
om617 - 0363-1.jpg
 
 
1/min
mbar
 
 
700-2600
from approx. 2400
3000
280-360 slowly dropping
approx. 60
 
 

 
 
Vacuum values in order
not in order
 
 

 
 
om617 - 0363-2.jpg
om617 - 0363-3.jpg
 
 
Perform testing individual components.
 
 

 
 
End of test
 
 

 
 
14.8-100/15 USA 1984 California F3
 
 

 
           

 

             
 

 
 
Testing individual components
 
 

 
 
Testing temperature sensor for coolant (83)
Engine stopped.
Pull plug from temperature sensor for coolant.
Test resistance against ground.
om617 - 0364-1.jpg
 
 
For nominal value refer to diagram.
Test resistance at three temperature measuring
points.
 
 
om617 - 0364-2.jpg
 
 
Example:
+ 20 °C = 2.2-2.8 + 80 °C = 290-364 +100°C= 140-222
 
 
Test
values in order
not in order
 
 
om617 - 0364-3.jpg
om617 - 0364-4.jpg
 
 
Renew temperature sensor
 
 
End of test
 
 

 
 
Testing rpm sensor (82)
Engine stopped.
Separate clutch (2) and test resistance with
multimeter.
Readout: 1.9 ±0.2
om617 - 0364-5.jpg
 
 
in order
not in order
om617 - 0364-6.jpg
 
 
om617 - 0364-7.jpg
Renew rpm sensor.
 
 
om617 - 0364-8.jpg
 
 

 
 
14.8-100/16 USA 1984 California F 3
 
 

 
             

 

             
 

 
 
Connection as above.
Push "V" button.
Read test value at the following engine speed:
om617 - 0365-1.jpg
 
 
1/min
V
 
 
700-800
>4M
 
 
Test values in order
not in order
om617 - 0365-2.jpg
 
 
om617 - 0365-3.jpg

 
 
Renew rpm sensor.
 
 

 
 
End of test
 
 

 
 
Voltage increasing with increasing engine speed.
 
 

 
 
Testing control rod travel indicator
Engine stopped, separate clutch (1). With multi­meter in position £2 (measuring range up toap-prox. 100 fi) and test resistance according to dra­wing.
Readout: 1-2 = approx. 25 ± 2 2-3 = approx. 25 ± 2 1-3 = approx. 50 ± 6
om617 - 0365-4.jpg
 
 
Readout in order
not in order
 
 

 
 
om617 - 0365-5.jpg
om617 - 0365-6.jpg
om617 - 0365-7.jpg
 
 
Exchange injection pump with control and travel indicator.
Attention!
The control rod travel is set by manufac­turer on test bench. Do not remove or change its function.
 
 
End of test
 
 

 
 
14.8-100/17 USA 1984 California F 3
 
 

 
             

 

               
 

 
 
Testing pressure converter (84)
Connect vacuum tester to vacuum line of con­nection (2). Run engine at idle speed. Read va­cuum value. Nominal value approx. 450 mbar.
om617 - 0366-1.jpg
 
 
Vacuum in order
not in order
 
 
om617 - 0366-2.jpg
om617 - 0366-3.jpg
 
 
Test vacuum lines according to function diagram. Test vacuum pump (43—660).
 
 
om617 - 0366-4.jpg
om617 - 0366-5.jpg
 
 
Connect vacuum tester with Y-distributor to connection (1). Connect multimeter with test cable to pressure converter. Push button ,,mA"
Read test values at the following engine speeds:
 
 
1/min
mbar
mA
 
 
700-2600 from approx. 2400 approx. 3000
280-360 dropping slowly approx. 60
^ 530
£370 0
 
 

 
 
Test
values in order
not in order
 
 
om617 - 0366-6.jpg
 
 
om617 - 0366-7.jpg

 
 
Current values in order, renew pressure converter.
Current values not in order, perform ac­tivation test according to electric wiring diagram. Renew control unit, if re­quired.
 
 

 
 
End of test
 
 

 
 
14.8-100/18 USA 1984 California F3
 
 

 
               

 

                 
 

 
 
Testing switchover valve (81)
Connect vacuum tester with Y-distributor to connection (a). Run engine at idle speed. Read vacuum value. Nominal value > approx. 600 mbar.
om617 - 0367-1.jpg
 
 
Vacuum in order
not in order
om617 - 0367-2.jpg
 
 
om617 - 0367-3.jpg

 
 
Test vacuum lines according to vacuum diagram. Test vacuum pump (43—660).
 
 

om617 - 0367-4.jpg
om617 - 0367-5.jpg
 
 
Connect vacuum tester with Y-distributor to connection (b). Connect multimeter with switchover valve. Push button "V=". Read test values at the following engine speeds:
 
 
1/min
mbar
Volt
 
 
700-800
1000-2500
>3000
approx. 600 0
0
approx. 12 0
 
 
Test
values in order
 
 
not in order
 
 

 
 
om617 - 0367-6.jpg
om617 - 0367-7.jpg
 
 
Voltage data in order, renew switchover valve.
Voltage data not in order, perform acti­vation test according to electric wiring diagram. Renew control unit, if required.
 
 

 
 
End of test
 
 

 
 
14.8-100/19 USA 1984 California F3