Note. A new O-ring will be required during installation.
Note. The following procedure only applies to models with the F8Q 620 engine (with Bosch fuel pump and without air conditioning).
Removing
1. The thermal actuator is located on the left end of the cylinder head (refer to accompanying illustration).
2. Partially drain the liquid from the cooling system as described in Chapter Maintenance.
3. Loosen the screw or nut and remove the lug from the cable on the fast idle lever on the fuel pump (refer to accompanying illustration).
4. Remove the cable cover from the bracket on the fuel pump.
5. Turn away a thermal drive from a head of the block of cylinders and remove a drive together with a cable. Remove O-ring (refer to accompanying illustration).
Installation
1. Install the actuator in place using a new O-ring and tighten it.
2. Fill the cooling system as described in Chapter Maintenance.
3. Insert the cable cover into the bracket on the fuel pump.
4. Insert the cable into the fast idle lever and place the tip on the cable, do not tighten the screw or nut yet.
5. Adjust the cable as described in the following paragraphs.
Check and adjustment
Note. During this procedure, it is necessary to measure the engine speed. A conventional tachometer, which operates from the impulses of the ignition system, cannot be used on diesel engines. To do this, there is a diagnostic clutch to which Renault diagnostic equipment is connected, but it is usually not available to a car enthusiast. If you cannot adjust the idle speed by ear or by using the tachometer on the dashboard, the following recommendations can be used.
- a) Buy or borrow an appropriate tachometer.
- b) Entrust the work to a Renault workshop or another specialist.
- With) Use the comparative method. The stroboscope is driven by a gasoline engine running at the desired speed. If the strobe is directed at the mark on the camshaft or fuel pump gear, the mark will appear stationary when the speed of both engines is the same (or a multiple of an integer). The pulley will rotate at half the speed of the crankshaft, but this will not affect the adjustment.
1. Warm up the engine (the cooling fan should turn on) and let it idle (refer to section Checking and adjusting idle speed and deceleration speed), proceed as follows.
And - the Lever of a fast idling; B - Gas lever; 1 - Fast idle adjustment screw; 2 - Idle adjustment screw; 3 - Screw for adjusting the speed of deceleration; 4 - Screw for adjusting the maximum engine speed
2. Move the fast idle lever on the fuel pump toward the flywheel until it touches the fast idle adjustment screw (refer to accompanying illustration).
3. Make sure that the fast idle speed matches the data given in Specifications. If necessary, loosen the locknut and turn the adjustment screw to achieve the specified Specifications fast idle speed. Finally, tighten the locknut.
4. Turn off the engine and disconnect the tachometer.
5. Now you need to adjust the fast idle cable. This is done in the following way.
6. The engine must be warmed up to normal operating temperature, and the fast idle lever should be in its original position (touch the idle speed screw but not the fast idle screw). Gently pull on the fast idle cable.
And - the Lever of a fast idling; C - Cable tip; 1 - Fast idle adjustment screw; x = 6.0 mm
7. Position the tip on the cable so that the distance between the edge of the fast idle lever and the tip is 6.0±1 mm (refer to accompanying illustration).
8. With the tip correctly positioned, tighten the screw.
9. When the engine is cool, check that the cable retracts the fast idle lever until it touches the fast idle adjustment screw. Warm up the engine to normal operating temperature and check again that the "X" between the edge of the fast idle lever and the tip of the cable corresponded to the given data (refer to illustration above). If this is not the case, the thermal actuator is probably defective.