Pic. 14.29. Elements of the fuel economy system: 1 - headlight switch; 2 – a control lamp of necessity of inclusion of higher transfer; 3 - control lamp for excessive opening of the throttle; 4 - ignition switch; 5 - storage battery; 6 - idle switch in the throttle position sensor; 7 - 5th gear switch; 8 – vacuum switch; 9 - ignition coil; 10 - to spark plugs
Elements of the fuel economy system on engines with the PBT system are shown in fig. 14.29. The system has two
control lamps, one serves as an indicator of the need for a higher gear, the other - an indicator of excessive throttle opening.
The control lamp for the need to shift into a higher gear lights up after the engine speed exceeds 2800 min-1 with the accelerator pedal pressed all the way down; does not work when engaged in 5th gear or when braking.
The over throttle warning light comes on if the intake manifold pressure drops below 96-140 mmHg. Art., and turns off if the pressure exceeds this limit.
Connect a tachometer to the engine to check the operation of the warning lamp. Start the engine and check that the control lamp lights up at an engine speed of 2650–2950 rpm-1 and remains on as long as the engine speed exceeds this value.
Disconnect the connector from the 5th gear switch on the gearbox and connect the connector pins together. After that the control lamp should not light up at increase in frequency of rotation of a cranked shaft of the engine.
To check the over throttle warning light, disconnect the tube from the vacuum switch and connect a vacuum pump to it. Turn on the ignition; the control lamp should light up when the pressure drops below 96–140 mm Hg. Art., and should go out when the specified pressure is exceeded.