Fuel System

Cold Start Injectors

Function: Centrally mounted injector that provides fuel to all cylinders to aid cold starting.

Availability: Full range of cold start injectors from Bosch for all L-Jetronic and K-Jetronic applications.

Fuel Distributor Heads (K-Jetronic)

Function: An extremely complex and precision-engineered device, the fuel distributor is the "brains" of the K-Jetronic fuel injection system. Found within its micro-precision housing is the fuel control plunger and the pressure differential valves (one per cylinder/injector), these are used to meter the amount of fuel delivered to each cylinder. Due to the complexity of this unit, and its almost scientific construction, cleanliness in the fuel system is of critical importance. Water and impurities must be kept out of the fuel system hence the fuel filter must be changed at regular intervals.

Availability: Automotive Service Solutions provides various services in relation to ECU's. New units are available for relevant applications as well as a testing, repair and changeover service for all ECU types.

Fuel Filters

Function: An essential part of the fuel system to remove impurities in order to protect the finely machined surfaces of fuel injectors, pump assemblies, pressure regulators and K-Jetronic fuel distributors. A quality EFI fuel filter removes particles down to 6 -10 microns in size and can also trap water.

Quality of the fuel filter is dependent on the overall design of the filter as well as the type of filtering paper used. Filters should be replaced at regular intervals, as most filters see the entire contents of the vehicle fuel tank pass though them twice every hour of operation.

Availability: Automotive Service Solutions stocks only premium quality Bosch and O.E. manufactured filters to suit all applications.

Mechanical Fuel Injectors (K-Jetronic)- The injectors used in the Bosch K-Jetronic fuel injection system are purely mechanical in their operation. They are opened once fuel pressure in the injection line has risen to a specific pressure (usually between 3.3 bar - 4.1 bar). A finely machined internal valve oscillates on its seat atomising the fuel as it passes through the injector.

Electronic Fuel Injectors- A solenoid operated valve that is energised for an amount of time as calculated by the ECU in reference to various pieces of information received. Two system variations exist, a multi-point or port injection arrangement (one injector per engine cylinder), and a throttle body (TBI) or central fuel injection (CFI) system. Injector designs vary, particularly with late model management systems, designs such as side or bottom feed are commonly used for high temperature/flow applications.

Availability: Automotive Service Solutions stock all varieties of fuel injectors, to suit European, Australian, Asian and US Imported vehicles from manufacturers including Bosch, Denso, JECS and Rochester. All applications catered for from standard O.E. applications to Motorsport needs. We also supply a full range of accessory/service parts including seals, filter baskets, protective caps and connector plug kits.

Pumps may be external of the fuel tank (in-line), or a submerged pump inside the fuel tank. Most external fuel pumps also utilise a pre-pump inside the fuel tank to feed the main pump with fuel. In-tank pumps are more common in modern EFI systems due to their cost and noise advantages.

Availability: Automotive Service Solutions supplies pumps from many manufacturers including Bosch, VDO, Nippon Denso, JECS, Walbro and AC Delco. Years of research has allowed us to gather cross reference information for many rare and unusual models as well as the common fast moving applications. Quality is vital with fuel pumps for reliability, don't accept non O.E. quality.

Warning - Replacement of fuel pumps should only be carried out by suitably qualified personnel. Replacement of all pre-filters and cleaning of fuel tank is mandatory.

Many later model units have full throttle enrichment facilities, to reduce control pressure under acceleration and provide extra enrichment.

Availability: New and changeover/reconditioned units are available as well as replacement connectors and banjo fittings.