Exhaust Gas Recirculation: Testing and Inspection

***UPDATED BY TSB 23124, NOVEMBER 1985

Fig. 126 E.G.R COMPONENTS:

E.G.R. component placement in engine compartment. Fig. 126.


(California market only)

Fig. 127 DISENGAGE COLD START DEVICE:

Check all hoses and connectors

Disengage cold start device:

- Loosen screw 1, push lever forward and turn sleeve 90°. Fig. 127.

NOTE:
Do not touch screw 2. If this screw is loosened, cold start device must be re-adjusted.

- Press lever rearward, against the stop.
- A = engaged B = disengaged.

Fig. 128 CHECK IDLE SWITCH:

- Connect a test lamp across positive terminal on solenoid valve and ground.
- Connect a vacuum gauge across E.G.R. valve and the yellow hose. Fig. 128.

Check idle switch:

- Switch ignition on. Test lamp should illuminate when pump lever rests on its stop. If not, check:
- Fuse # 11 1984 model year.


Check E.G.R. time relay for proper delay time:

- Move pump lever until test lamp goes out and hold arm in this position until test lamp illuminates again.
- In automatic transmission vehicles, this should occur in approximately 4 seconds; manual transmission vehicles should take approximately 5 seconds. If not, replace and retest with new time relay.
- Check that test lamp is out when 5th gear (overdrive) is engaged.
- Switch ignition off.

Fig. 129 VOLVO GAUGE 5285:

Check idle switch setting:

- Move pump lever until switch clicks.
- Hold pump lever in that position and measure clearance between screw and stop for low idle speed.
- Correct clearance: 2-4mm (0.08-0.16").
- Use Volvo gauge #5285 or appropriate feeler gauge for measurement. Fig. 129.


Adjust low idle switch:

- Insert gauge (3 mm = 0.12") between screw and stop for low idle speed.
- Loosen screw while holding low idle switch and turn switch until it clicks.
- Tighten screw and recheck idle switch setting.

Fig. 130 VACUUM GOVERNOR:

Check vacuum governor:

- Disconnect gray hose to vacuum governor at thermo-vacuum valve and connect a vacuum pump with minimum capacity of: 50 kPa = 7 psi = 14.25 in. Hg Fig. 130.

Fig. 131 CUT ELBOW FITTING:

- Vacuum pump for AC system can be used.
- Cut an elbow fitting and connect hose disconnected at thermo-vacuum valve. Fig. 131.
- Install Volvo gauge #5285 so that long part of tool aligns pump housing.



- Switch ignition on.
- Start vacuum pump. Gauge reading should be 38 ± 1 kPa = 5.40 ± 0.14 psi = 10.99 ± 0.28 in.Hg. If gauge reading is incorrect, loosen the two screws holding vacuum governor and move it until correct reading is obtained.
- Switch ignition off.
- Switch off vacuum pump and remove gauge tool.





Check vacuum governor full load switch:

- Switch ignition on.
- Move pump lever; wait until test lamp illuminates. Continue movement until lamp goes out (must happen within 5 seconds); read vacuum gauge when the full load switch breaks contact. Correct reading is 20 ± 2 kPa = 2.45 ± .25 psi = 4.98 ± 0.5 in.Hg
- If incorrect: use screw on switch to adjust.
- Disconnect vacuum pump.

Fig. 132 RECONNECT COLD START DEVICE:

Check thermo-vacuum valve:

- Reconnect cold start device.
- Reconnect connections and disconnect test lamp. Leave vacuum gauge connected.
- Start engine. Vacuum gauge should not indicate vacuum until engine has reached operating temperature of approx. 45°C (113°F). If thermo valve opens earlier or not at all, replace and retest with new thermo valve. Fig. 132.