GM TBI injectors, color codes, and flow rates


These injectors are rated at the pressure used by the factory, about 13 PSI
Color code Application Flow rate Part #
Black/White 1-3/8" bore 2bbl, from 2.8l truck ??? GM 5235430 *RPD
Yellow/Blue 4.3L ??? GM 5235203 *RPD
Green/White 5.0L 40 lb/hr GM 5235279 *RPD
Orange/Black 5.7L pickup 55 lb/hr GM 5235206 *RPD
Yellow/Brown 5.7L Cop Car 65 lb/hr ???
Blue/Black Late big block pickup 80 lb/hr GM 1708430 *RPD
Dark Red/Dark Blue big block pickup 90 lb/hr GM 5235231 *RPD
The picture below shows where to look to find the color codes in the injector. This picture is of a 4.3 throttle body. The injectors have a yellow/blue color code, each of which is visible on top of the injector.
Mis-Matched TBI injectors
The Throttle Body Injection (TBI) assembly installed on the 1987 4.3L light duty truck engine uses injectors with DIFFERENT flow rates in each throttle bore for improved emission control. The TBI units involved are model numbers 17087090 and 17087162. If the injectors are removed for any reason, care must be taken to make sure they are installed in their proper location.

INJECTOR LOCATION INFORMATION

Throttle Lever Side Bore COLOR-CODED ORANGE AND GREEN

TPS Side Bore COLOR-CODED PINK AND BROWN
Maintained by Brian Koontz, brian@diy-efi.org

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