Method of manufacturing a polymeric bodied fuel injector

1. A method of manufacturing a fuel injector comprising:

forming a polymeric housing over a coil assembly and electrical connectors to provide a polymeric passage extending from an inlet proximate a first external seal to an outlet proximate a second external seal along a longitudinal axis, the polymeric passage directly facing the longitudinal axis;

inserting components into the polymeric passage from at least one of the inlet and outlet; and

securing a polymeric support member of a metering assembly directly to the polymeric housing proximate the outlet.

2. The method of claim 1 , wherein the forming comprises insert molding the coil assembly and electrical connectors, the coil assembly including a bobbin and multiple wire windings surrounded by a coil housing contiguous to a flux washer disposed generally orthogonal to the longitudinal axis.

3. The method of claim 2 , wherein the insert molding comprises providing an external seal retention pocket proximate the inlet and outlet.

4. The method of claim 3 , wherein the insert molding comprises providing a polymeric passage having at least two different diameters, each spaced apart from the other along the longitudinal axis.

5. The method of claim 4 , wherein the insert molding comprises hermetically sealing the coil assembly from the polymeric passage.

6. The method of claim 5 , wherein the insert molding comprises providing a nylon material generally opaque to radiant energy.

7. The method of claim 1 , wherein the inserting comprises inserting a closure assembly, pole piece, resilient bias member and filter assembly through the inlet.

8. The method of claim 7 , wherein the securing comprises insert molding a seat to form the metering assembly having the seat secured to the polymeric support member.

9. The method of claim 8 , wherein the securing comprises inserting a guide member in the metering assembly, the guide member having a central aperture to guide the closure member along the longitudinal axis and at least one aperture offset to the longitudinal axis.

10. The method of claim 9 , wherein the securing comprises securing a metering disc to the seat.

11. The method of claim 10 , wherein the securing comprises bonding the polymeric support member to the polymeric housing proximate the outlet.

12. The method of claim 10 , wherein the securing comprises laser welding the polymeric support member to the polymeric housing proximate the outlet.

13. The method of claim 1 , wherein the inserting of components comprises:

connecting an armature to a closure member to provide an armature assembly;

coating an end face of a pole piece having at least one continuous recessed surface formed on the outer circumference of the pole piece; and

inserting the armature assembly and pole piece into the polymeric passage from the inlet to a position proximate the outlet;

inserting a biasing spring and adjusting tube assembly into the polymeric passage, the adjusting tube assembly having a filter element coupled to an adjusting tube.

14. A method of manufacturing a fuel injector comprising:

forming a polymeric housing over a coil assembly and electrical connectors to provide a polymeric passage extending from an inlet proximate a first external seal to an outlet proximate a second external seal along a longitudinal axis, the polymeric passage directly facing the longitudinal axis;

inserting components into the polymeric passage from at least one of the inlet and outlet; and

securing a polymeric support member of a metering assembly directly to the polymeric housing proximate the outlet;

wherein the inserting of components comprises;

connecting an armature to a closure member to provide an armature assembly;

coating an end face of a pole piece having at least one continuous recessed surface formed on the outer circumference of the pole piece;

inserting the armature assembly and pole piece into the polymeric passage from the inlet to a position proximate the outlet; and

inserting a biasing spring and adjusting tube assembly into the polymeric passage, the adjusting tube assembly having a filter element coupled to an adjusting tube; and

wherein the securing comprises:

providing a metering assembly having a seat secured to a polymeric support member, the polymeric support member having at least a retention portion generally transparent to laser light;

inserting an armature guide member into the metering assembly;

inverting the metering assembly;

orientating a metering disc with respect to the seat;

securing the metering disc to the seat; and

coining a surface of the seat to provide a sealing surface for a closure member.

15. The method of claim 14 , wherein the securing comprises:

coupling the retention portion of the metering assembly to the polymeric housing; and laser welding the retention portion to the polymeric housing.

16. The method of claim 15 , further comprising:

calibrating the fuel injector to achieve a desired response time as measured from when the coil is energized to when the closure member is contiguous to the pole piece.

17. The method of claim 16 , wherein the calibrating comprises adjusting a position of the adjusting tube assembly with respect to the armature assembly.