Throttle body assembly of Fiat Punto

Removal

1 Disconnect the battery negative terminal.
2 Remove the air cleaner assembly.
3 Disengage the accelerator inner cable from the throttle cam, and withdraw the outer cable from the rubber grommet on the mounting bracket.
4 Remove the electronic control unit.
5 Disconnect the wiring connectors from the throttle potentiometer and the idle control stepper motor (see illustration).



Disconnect the wiring connectors from the throttle potentiometer and the idle control stepper motor (arrowed)


6 Undo the retaining screw and disconnect the ECU earth lead from the front of the throttle body (see illustration).



Disconnect the ECU earth lead (arrowed) from the throttle body


7 Slacken and remove the three bolts securing the throttle body assembly to the inlet manifold, then remove the assembly and collect the sealing O-ring (see illustration).



Throttle body retaining bolts (arrowed)


Refitting

8 Refitting is a reversal of the removal procedure, bearing in mind the following points:
a) Ensure the throttle body and inlet manifold mating surfaces are clean and dry, then fit the throttle body with a new O-ring, and securely tighten the retaining bolts.
b) Refit the electronic control unit.
c) Adjust the accelerator cable.

Fuel rail and injectors of Fiat Punto

Removal

9 Disconnect the battery negative terminal.
10 Remove the air cleaner assembly.
11 Depressurise the fuel system.
12 Disconnect the wiring connectors at the fuel Injectors (see illustration).



Disconnect the wiring connectors at the fuel injectors


13 Disconnect the fuel supply pipe at the quick-release connector on the left-hand end of the fuel rail (see illustration)



Disconnect the fuel supply pipe at the fuel rail quick-release connector


14 Unscrew the two bolts securing the fuel rail assembly to the inlet manifold, then carefully pull the injectors from their manifold locations (see illustration). Remove the assembly from the engine and remove the injector lower O-ring seals.



Unscrew the two bolts (arrowed) securing the fuel rail assembly to the inlet manifold


15 The injectors can be removed individually from the fuel rail by extracting the relevant metal clip and easing the injector out of the rail. Remove the injector upper O-ring seals.
16 Check the electrical resistance of the injector using a multimeter and compare it with the Specifications. Note: If a faulty injector is suspected, before condemning the injector it is worth trying the effect of one of the proprietary injector-cleaning treatments.

Refitting

17 Refitting is a reversal of the removal procedure, bearing in mind the following points:
a) Renew the injector O-ring seals, and smear them with a little petroleum jelly before assembling. Take care when fitting the injectors to the fuel rail and do not press them in further than required to fit the retaining clip otherwise the O-ring seal may be damaged.
b) Ensure that the injector retaining clips are securely seated.
c) On completion check the fuel rail and Injectors for fuel leaks.

Idle control stepper motor of Fiat Punto

18 The idle control stepper motor is an integral part of the throttle body and cannot be individually renewed.

Throttle potentiometer of Fiat Punto

19 The Idle control stepper motor is an integral part of the throttle body and cannot be individually renewed.

Intake air temperature/pressure sensor of Fiat Punto

Removal

20 Disconnect the battery negative terminal.
21 Remove the air cleaner assembly.
22 Disconnect the wiring connector, undo the two retaining screws and remove the sensor from the left-hand end of the inlet manifold (see illustration).



Intake air temperature/pressure sensor wiring connector (A) and retaining screws (B)


Refitting

23 Refitting is a reversal of the removal procedure.

Crankshaft TDC sensor of Fiat Punto

Removal

26 The crankshaft TDC sensor is located adjacent to the front facing side of the crankshaft pulley (see illustration).



Crankshaft TDC sensor location (arrowed)


27 Disconnect the battery negative terminal.
28 Remove the timing belt upper and lower covers.
29 Undo the bolt securing the sensor to the oil pump casing and remove the sensor from its location.

Refitting

30 Locate the sensor in position and secure with the retaining bolt.
31 Engage the sensor wiring harness with the upper and lower timing belt covers, then refit the covers.

Camshaft position sensor of Fiat Punto

Removal

33 Disconnect the battery negative terminal.
34 Disconnect the wiring connector from the camshaft position sensor located at the timing belt end of the camshaft cover (see illustration).



Camshaft position sensor wiring connector (A) and retaining bolt (B)


35 Undo the retaining bolt and withdraw the sensor from the camshaft cover.

Refitting

36 Refitting is a reversal of the removal procedure.

Electronic control unit (ECU) of Fiat Punto

Removal

37 The electronic control unit is attached to the rear of the throttle body.
38 Disconnect the battery negative terminal.
39 Remove the air cleaner assembly.
40 Rotate the wiring connector locking catches and disconnect the two wiring connectors from the top of the ECU (see illustrations).



Rotate the ECU wiring connector locking catches ...



… and disconnect the two wiring connectors from the ECU



41 Undo the two mounting bolts and removal the ECU from the throttle body (sea illustrations).



Undo the two mounting bolts (arrowed)...



… and remove the ECU from the throttle body


Refitting

42 Refitting is a reversal of the removal procedure.

Inertia safety switch of Fiat Punto

Removal

43 Disconnect the battery negative terminal.
44 Working under the facia on the right-hand side, move away the floor covering and side him for access to the switch.
45 Disconnect the wiring connector, then undo the two bolts and remove the switch worn its location.

Refitting

46 Refitting is a reversal of the removal procedure.

Vehicle speed sensor of Fiat Punto

Note: On cars equipped with ABS, the vehicle speed sensor signal is supplied to the ECU by the ABS wheel speed sensors.

Removal

47 The vehicle speed sensor is located on the top of the transmission differential housing.
48 Disconnect the battery negative terminal.
49 Firmly apply the handbrake, then jack up the front of the car and support it securely on axle stands.
50 Disconnect the sensor wiring connector then unscrew the sensor from the differential housing.

Refitting

51 Refitting is a reversal of the removal procedure.