Fig. 13

TEST EQUIPMENT

  The following items of test equipment are required for checking the petrol injection system:
(i) Pressure gauge (see Figure 13) scaled for reading up to at least 160 lbf/in2 (1103.20 kN/m2).
(ii) A ‘T’ piece, two -3/8” B.S.P. connections (one male and one female) and a suitable connection for the pressure gauge.
(iii) A vacuum gauge 0-26” Hg (0-711 mm Hg).
(vi) Ammeter (scale 0-10A).
(v) Voltmeter (scale 0-18V).

Important:
  The fuel pump should never be switched on while any part of the fuel system, normally pressurized, is dismantled. Further, the fuel pump should not be run for long periods, when the engine is stationary. The following precautions should also be taken before carrying out systematic fault diagnosis:
(I) Whenever the pipes are removed from the petrol injection system, and the ignition is switched on, the feed cables must be disconnected from the pump.
(ii) Cover exposed pipe with blanking plugs.
(iii) Any sealing ring, removed during testing must not be re-fitted, but must be renewed.
When checking the ‘PI’ system the test equipment should be connected as follows:
(a )Vacuum gauge: ‘T’ piece between (center pair) air intake manifold and the metering distributor vacuum connection.
(b) Pressure gauge: ‘T’ piece connected into petrol inlet at metering unit.
(c) Voltmeter: Connected across pump motor terminals.
(d) Ammeter: Connected in series with either of the pump motor leads.
With engine running at ‘tick over’ speed (850 rev/ mm) gauges and meters should read as follows:
Pressure gauge: 100-110 lbf/in2 (689.50-758.50 kN/m2) all models.
Vacuum gauge: TR5/6 7” Hg (180 mm Hg) 2.5 litre 12” Hg (305 mm Hg).
Volt drop should not exceed 1.5 volts. Ammeter: should read not more than 5.5 amps.

                               Fig. 14

DIAGNOSING FAULTS IN THE PETROL INJECTION SYSTEM
The following is a list of the more common faults encountered on PI equipped cars:
1. Misfiring
     (a) After cold start
     (b) After hot soak
2. Rough idling
3. Over-fuelling on one or more cylinders
4. Under-fuelling on one or more cylinders
5. Lack of response
6. Engine cutting out
7. Vapor locking
8. Excessive fuel consumption
9. Engine fails to start
Important:
Check Excess Fuel Lever
Before carrying out the systematic test procedure, the operation of the over-fuel lever should be checked over the complete test range as it may be the cause of symptoms 1 and 9 above. Ensure the lever moves into the fully open position, and returns to the fully closed position, when the panel control is operated.
The clearance between the screw and the lever (when the lever is in the closed position) should be 0.004”- 0.008” (0.10-0.20 mm), (Figure 14). 

(Continued)