Vphix FJ503 Spider Fuel Injectors for 4.3L V6 — Bracket Kit for Chevy GMC Isuzu, Direct Replacement

Vphix FJ503 spider fuel injectors with bracket are a direct-replacement injector set engineered to restore fuel delivery for V6 4.3L Chevrolet, GMC and Isuzu engines from the mid‑1990s through the early 2010s.

This injector kit includes spider-style injectors and mounting bracket made to match OE form and function for many 4.3L V6 applications, covering popular models such as Astro, Blazer, Silverado, Sierra, Savana and more. The set lists multiple OEM part number cross-references and fits a broad range of model years; installers should expect to make minor manual adjustments for optimal seating and are advised to use professional installation where appropriate.

Which vehicles and years does this Vphix injector set fit?

The FJ503 kit is designed for 4.3L V6 engines across several GM and Isuzu platforms. Coverage spans model years roughly from 1996 through 2014 depending on the vehicle and configuration. Always verify compatibility using engine code and part number cross-references before purchase.

• Chevrolet: Astro (1996–2005), Blazer (1996–2005), Express 1500/2500 (1996–2014/2005), Silverado 1500 (1999–2013), S10, C1500, P30/P3500 varieties
• GMC: Jimmy (1996–2002), Safari (1996–2005), Sonoma (1996–2004), Sierra 1500 (1999–2013), Savana 1500/2500 (1996–2013/2006)
• Isuzu/Oldsmobile/Other: Hombre (1997–2000), Bravada (1996–2001) when equipped with V6 4.3L

What does the kit include and which part numbers match it?

The package supplies spider-style fuel injectors with the mounting bracket and necessary hardware to replace worn injectors on compatible V6 4.3L engines. The listing provides many OEM cross numbers so you can confirm fitment with existing components.

• Included: spider injectors, bracket, and mounting components where applicable
• Cross-references: 12568332, 217-3028, 17113295, 17114164, 17091628 and additional OEM numbers
• Designation: Vphix part FJ503 (also referenced as FJ10565 in some catalogs)

How should installation and adjustment be handled?

These injectors may require manual adjustment of the injector shape or seating to align correctly with the fuel rail and intake spider. Improper installation can lead to leaks or poor spray pattern; a qualified technician will ensure precise positioning, sealing and electrical connection.

• Inspect rail and O‑rings for damage; replace seals when installing
• Hand‑fit injectors, then torque mounting hardware to spec and check for leaks
• Recommend professional installation for rail fitting, fuel pressure checks and ECU diagnostics

What performance or maintenance benefits can owners expect?

Replacing worn or damaged injectors with this Vphix kit can improve fuel spray consistency and restore smoother idle and throttle response when fuel delivery was the limiting factor. While not a performance upgrade, fresh injectors help the engine run as designed and reduce misfire or hesitation caused by failing injectors.

• Restores consistent injector spray pattern and flow for engines originally using spider injectors
• Reduces rough idle, stumble or fuel delivery‑related drivability issues
• Includes OEM cross numbers for ease of fitment confirmation and parts matching

Who is this for: The Vphix FJ503 spider injector set is aimed at DIY mechanics, restoration shops and professional technicians working on GM and Isuzu 4.3L V6 vehicles from the late 1990s to the early 2010s that require a direct-style replacement. If you’re restoring drivability, replacing leaking injector spiders, or matching OE part numbers during an engine rebuild, this kit provides the compatible components — just plan for careful fitment checks and professional installation when in doubt.