NCT Manual. - National Car Testing Service

NATIONAL CAR TEST (NCT) MANUAL 2012
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FUEL SYSTEM
Method of Testing
1. Examine the fuel tanks to see that they are suitable, free from advanced rust and are firmly held and secure on their
mountings. In the case of Liquid Petroleum Gas/Compressed Natural Gas, check that the fuel tank is not damaged.
2. Examine fuel tank straps or supports and mounting brackets to see that they are secure and free from fracture and that none is
missing.
3. Examine the mounting bracket bolts to chassis/body to see that they are secure.
4. Where the LPG/CNG fuel tank is fitted inside the vehicle, check that the tank safety valve and filler valve are either piped
separately to the outside of the vehicle or contained in a gas tight sub-compartment which is vented to the outside of the
vehicle.
5. Check that any ducting used for venting sub-compartments or tank valves is not damaged or blocked.
6. Check that no fuel tank is fitted to the roof of the vehicle.
7. Where LPG/CNG is fitted, check that the manual hand valve on the tank can be closed off. Or where a solenoid is fitted in
place of or as an extra protection for the manual valve, check that it can be heard to open and close when the ignition key is
switched on and off with the LPG/CNG switch in the ‘on’ position.
8. In CNG systems, a second manual valve will normally be found near the filler valve which is usually in the engine
compartment. This should also be checked.
9. Check that a fuel tank cap is present and of the correct type. Check that the fuel cap seal is present and is not damaged.
10. Check that there are no leaks at all from the system in the case of petrol. In the case of diesel, check that there are no leaks
such that fuel is dripping on to the ground. In the case of LPG/CNG, check if a pressure leak (hissing noise) can be heard.
11. Examine fuel pipes to see that they are securely clipped to prevent damage by vibration, chafing or cracking.
12. Check that pipelines/hoses are not damaged or deteriorated (e.g. kinked or flattened) and are not in a position to be fouled by
moving parts or the road surface.
13. Check that all components of the fuel system are securely mounted.
14. While seated in the driving position, check that the throttle control is:
(a) functionally complete.
(b) not cracked, fractured or excessively worn or corroded.
(c) not obstructed or impeded in its travel.
15. Check that the excess fuel device on diesel-engine vehicles cannot be readily operated from within the cab if it is of a type
which, with the engine running, will cause an increase in smoke.
16. Check that the engine stop control is working satisfactorily on diesel engine vehicles. Where LPG/CNG is fitted, check that the
engine fuel supply solenoids (usually in engine compartment for each fuel used) can be heard to open and close when each
fuel system is selected on the dash switch.
17. Check that the air filter is present and securely fitted.
NOTES
1. The extent of this inspection is limited to those parts which can be seen and which are readily accessible
without dismantling.
2. All fuel tanks on the vehicle are included in the inspection.
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