Fuel Injetor System Service
The proper steps in fuel injector system service are:
- Check fuel pump operating pressure and volume. Test pressure regulator for operation and leakage. Flush entire fuel rail and upper fuel injector screens to include pressure regulator. Clean fuel injectors. Decarbon engine assembly. Clean throttle plate and idle air control (IAC) passages. Check minimum air flow rate and adjust if needed.
- Relearn onboard computer.
All eight steps may be performed using one of the "two-line" fuel injector service units. (Carbon Clean, Injector Test, DeCarbon and Motor-Vac, to name a few.)
Check fuel pump operating pressure and volume
The missing link here is volume, as most working technicians assume that if the pressure is correct, the volume is OK also! By hooking up a fuel pressure tester to the fuel rail inlet and return, and using the pressure side feed t-Ed into the fuel unit, we can quickly test the fuel pressure with engine running but also at the same time test the volume of the pump by stealing fuel into our holding tank (one pint in 30 seconds is the usual specification). When proper volume is flowed into the tank, we would shut down the engine and change hose connections to allow the machine to be put in control of the fuel supply system. The two line system would be attached to inlet and return on the fuel rail, with the vehicle's onboard system being "looped" and returning fuel to the tank. This prevents disabling of the factory unit.
Test pressure regulator for operation and leakage
At this time, the regulator would be tested for operational pressure and proper regulation including leakage. (This works well as the operator has total control of rail pressure with the unit control valve.)
[ back ]
|
