Fuel Pump Afterrun System, Checking
Fuel pump afterrun, checkingCheck this first:
- battery voltage OK
- fuel tank must be 1/4 full, minimum
WARNING: Fire hazard. Do have anything in area that can ignite fuel.
- connect pressure tester VAG 1318 using adaptors 1318/1 and 1318/11 between fuel distributor 1 and pressure switch 2
NOTE: The shutoff valve must be open (lever in direction of fuel flow).
CAUTION: When loosening the line at the fuel distributor, place a rag around the connection to avoid the risk of being sprayed.
- start engine and run at idle
- observe fuel pressure
- approximately 2.5 bar (36.3 psi)
- switch ignition OFF
Remove harness connector from pressure switch 1 and measure resistance between pressure switch terminals.
- 0 Ohms approximately
- remove harness connector from ambient temperature switch for fan afterrun 2 and connect to ground (-) using adapter wire from VW 1594 kit
- radiator fan MUST run
- re-connect pressure switch harness connector
- switch ignition ON then switch OFF
- after about 2-3 minutes fuel pumps MUST run
- re-connect ambient temperature switch harness connector
- fuel pump must NOT run
- remove harness connector from pressure switch and measure resistance between terminals
- 0 Ohms approximately
- reduce system pressure by carefully loosening pressure gauge/adaptor VAG 1318/1 at connection
CAUTION! When loosening the adaptor place a rag around the connection to avoid the risk of being sprayed.
The switch must open (infinite) when pressure drops below 1 bar (14 psi).