Air Injection Control Valve: Service and Repair
Replacing Anti-Run-On Valve For Secondary Air
If the anti-run-on valve or the check valve are defective, the secondary air system must be converted to the system used as of model year 2000. A list of new or omitted parts is attached to the aforementioned Technical Information document.
Diagram Of Secondary Air Injection Up To Model Year 1999
Diagram Of Secondary Air Injection As Of Model Year 2000
Removing Anti-Run-On Valve And Check Valve
NOTE:
- The removal of a seat is recommended in order to access the engine more easily in the passenger compartment and to avoid damaging the seats.
- A second person is required for removing/fitting the convertible-top compartment lid to avoid damage.
1. Move convertible top to service position, remove convertible-top compartment lid. To do this, unclip the plastic covers (Item 40) on the cover, remove 1 collar screw (Item 14) and one bolt (Item 13) using a retaining clip (Item 8) to the left and right on the fixing lever. Use the Spring-fix system assembly tool for pin circlips No. 131 to remove the retaining clips.
2. Remove the engine compartment lid and the maintenance cover.
3. Attach protective covers to the rear of the vehicle to avoid damaging the paint, etc.
NOTE: Note the work instructions for disconnecting and reconnecting the battery.
4. Disconnect battery.
5. Unscrew drive belt.
6. Release box for B+ connector. To do this, unscrew the two hexagon-head bolt screws on the crankcase and set the box to one side.
CAUTION:
- Pentosin is hazardous to the health.
- Wear protective gloves and goggles. If the eyes or skin come into contact with the fluid, wash immediately with water.
- Collect emerging Pentosin.
- Protect the leads against soiling and damage with caps.
- Clean hoses which come into contact with Pentosin thoroughly.
7. Remove supply tank of the power steering system. To do so, suck fluid (Pentosin) out as much as possible. Then open the bayonet lock -arrow- below on the expansion tank and remove the tank. If necessary, clean up any Pentosin that has spilt using a cloth. Close the opening in the servo pump with a clean plug.
NOTE: The air conditioning circuit must not be opened to loosen the air conditioning compressor.
8. Loosen air-conditioning compressor. To do this, unscrew the two hexagon-head bolts at the front -arrows- on the side of the maintenance opening (in the passenger compartment).
9. Unscrew the fastening screw at the back -arrow- from the engine compartment side. This is positioned between the intake manifolds of the fourth and fifth cylinders.
10. Disconnect the ground connection cable plug. Lift the air conditioning compressor with the connected leads out of the engine compartment and set them on a support.
11. Loosen the generator and lay it to one side.
12. Loosen the ground cable on the bracket that is attached to the body for the secondary air pump. To do this, unscrew the M8 hexagon nut on the bracket and lay the ground cable to one side.
13. Remove the secondary air pump. To do this, pull off the hose to the anti-run-on valve, unscrew 3 M6 collar nuts on the bracket and pull off the cable plug. Lever the pump out of the bracket.
14. Unscrew the fuel connection pipe of cylinder bank 1 - 3 on the intake distributor. To do this, unclip the wiring harness from the wire retainers and remove the 2 M6 x 12 hexagon-head bolts. Carefully take out the fuel collection pipe, including the injection valves, from the intake distributor and lay it to one side. Replace the 0-rings on the injection valves before installation.
15. Remove the air guide cowl between the air filter housing and throttle body. Do this by unscrewing the screw-type hose clamps on the air filter housing and throttle body and lift the cowl out of the engine compartment.
16. Remove intake distributor, cylinder bank 1 - 3. Do this by unscrewing the 2 screw-type hose clamps on the rubber sleeves to the right on the intake distributor centre and on the tuning pipe. Then unscrew the 6 M6 x 35 micro-encapsulated hexagon-head bolts on intake distributor 1 - 3. Pull off the engine compartment temperature sensor; pull off the positive crankcase ventilation line on the oil mist separator. Release the intake distributor from the rubber sleeves and lift it up out of the engine compartment.
17. Seal intake openings in the cylinder header with plugs.
18. Remove intake distributor centre and tuning pipe. Unscrew the 2 screw-type hose clamps on the rubber sleeves on the left. Unscrew the M6 fastening nut on the throttle body, pull off the positive crankcase ventilation line and remove the intake distributor centre. Pull off the existing vacuum lines on the rubber sleeves of the tuning pipe and remove the tuning pipe.
19. Remove oil filler neck. Remove 1 M6 hexagon-head bolt and pull the oil filler neck out of the crankcase. Replace 0-ring.
20. Open the spring band clamp on the connecting hose to the secondary air pump -arrow A- on the anti-run-on valve -arrow- and pull off the hose.
21. Unscrew the air line union nut (hexagon a/f 22) on the distributor housing.
22. Pull off the vacuum lines on the vacuum reservoir and anti-run-on valve, unscrew 2 M6 x 20 -1- hexagon-head bolts for the distributor housing on cylinder head 1 - 3. Unclip switch-over valve on distributor housing. Remove distributor housing including vacuum reservoir, check valve and anti-run-on valve from the engine. Unscrew fastening screw from vacuum reservoir, remove reservoir.
23. Unscrew 2 M6 x 16 hexagon-head bolts -1- for the air line on cylinder head 4 - 6, remove air line.
Installing Anti-Run-On Valve (Combination Valve)
1. Clean the sealing surfaces on both cylinder heads with a clean cloth soaked in cleaning fluid (e.g. solvent naphtha, acetone).
2. Prepare new parts for installation. Mount anti-run-on valve (combination valve) with seal and 2 M6 x 16 hexagon-head bolts on the distributor housing.
Tightening torque 10 Nm (7.5 ftlb.)
The figure shows the new distributor housing with anti-run-on valve (combination valve), seals and screws
3. Mount vacuum reservoir on the new distributor housing using fastening screw.
4. Fix air line in installation position. Position line flange with new seal and 2 M6 x 16 hexagon-head bolts on cylinder head 4 - 6 -1-. Insert spacer sleeve for air conditioning compressor -2-.
5. Position distributor housing with vacuum reservoir on the air line with union nut.
6. Insert a new seal between the distributor housing and cylinder head 1 - 3, screw in and tighten 2 M6 x 20 hexagon-head bolts -1-. Clip in the switch-over valve, attach vacuum lines to the anti-run-on valve and the vacuum reservoir.
Tightening torque 10 Nm (7.5 ftlb.)
7. Tighten 2 M6 x 16 hexagon-head bolts for the air line on cylinder head 4 - 6.
Tightening torque 10 Nm (7.5 ftlb.)
8. Tighten the air line's M20 x 1.5 union nut (hexagon socket a/f 22) on the distributor housing.
Tightening torque 25 Nm (19 ftlb.)
9. Fit a new connecting hose with spring band clamp on the flange of the anti-run-on valve.
10. Insert oil filler neck with new 0-ring and tighten with an M6 x 16 hexagon-head bolt.
Tightening torque 10 Nm (7.5 ftlb.)
11. Fix tuning pipe and intake distributor centre with screw-type hose clamps. Attach positive crankcase ventilation line to the distributor and vacuum line to tuning pipe rubber sleeve. Tighten M6 fastening nut for throttle body.
Tightening torque 10 Nm (7.5 ftlb.)
12. Clean sealing surfaces of intake distributor cylinder side 1 - 3. Install intake distributor. Replace molded seals and micro-encapsulated M6 x 35 hexagon-head bolts. Attach positive crankcase ventilation line to the oil mist separator, attach engine compartment temperature sensor.
Tightening torque 10 Nm (7.5 ftlb.)
13. Install air guide cowl.
14. Install fuel collection pipe. Replace 0-rings on the injection nozzles, insert the fuel collection pipe in the intake distributor and tighten with 2 M6 x 12 hexagon-head bolts.
Tightening torque 10 Nm (7.5 ftlb.)
15. Install secondary air pump. Attach cable plug and tighten hexagon nuts on the bracket.
Tightening torque 10 Nm (7.5 ftlb.)
16. Fit ground cable to bracket with 1 M8 hexagon nut.
Tightening torque: 23 Nm (17 ftlb.)
17. Install generator.
NOTE: Before installing the air conditioning compressor, check whether the spacer sleeve is inserted for the rear fastening screw.
18. Install air conditioning compressor. Attach ground cable, position the rear M8 x 120 hexagon-head bolt between cylinder intake manifolds 4 and 5 -arrow-. Position the two front M8 x 90 screws and tighten all 3 screws.
Rear fastening screw for air conditioning compressor
Tightening torque: 23 Nm (17 ftlb.)
19. Install supply tank for power steering system. Ensure that the bayonet lock is sealed securely.
20. Install box for B+ connector, tighten 2 hexagon-head bolts.
Tightening torque 10 Nm (7.5 ftlb.)
21. Fit and tension drive belt again.
NOTE: Note the work instructions for disconnecting and reconnecting the battery.
22. Connect the battery.
23. Fill Pentosin for power steering system.
24. Remove protective covers.
25. Install engine compartment lid and maintenance cover.
NOTE: A second person is required for removing/fitting the convertible-top compartment lid to avoid damage.
26. Install convertible-top compartment lid.
27. Install seat.
28. Close convertible top.
Tightening Torques
