Grumpy

GM TBI injectors, color codes, and flow rates

These injectors are rated at the pressure used by the factory, about 13 PSI
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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

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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.

dimented24x7

iTrader: (2)

good info... There is a similar thread over on the tbi board as well.

Bulldog92

iTrader: (1)

Where do I look to find the color code on the injector? I installed a 454 TBI on my 350 H.O. from a 1995 Chevy C3500 w/a 454 and I'd like to know the exact flow rate for the injectors so that I can set my BPC properly (see my posts at https://www.thirdgen.org/techbb2/sho...hreadid=193715 for more info).

It'd be great if there were a listing of flow rates by GM part number...here's the part numbers I found on the top of the injectors from the 454 TBI:

Top: 17104288xACR
Bottom: 8303 GM

I called just about every GM dealership in the area as well as sent an e-mail to ACDelco, but no one knows anything specific about TBI injectors. I am being told by a fellow TGO member that my part number corresponds to a 305 injector, so I just want to verify I have the correct injectors. I thought I was getting injectors in the 80-90 pph range, but now I'm not sure.

Grumpy

The Standard Brand Ignition Catalogs used to carry all the part nos. and then you had to do a reverse look up to find their application. Dunno how much they've changed in the last 5 years thou.

The colors are right underneath where the connector plugs onto the injector.

Bulldog92

iTrader: (1)

I did find an online version of the catalog for Standard Motor Products at:

https://www.rockauto.com/dbphp/dbpag...CTS/ELECTRICAL

I did a lookup for the injector for a 1995 454 TBI from a C3500 pickup, but it did not list 17104288 as one of the GM part numbers...it only listed 17094060, 17113080 and 17113094. I don't know if that means my injectors are incorrect or just that they failed to mention all of the possible injector options that year. I attempted to just do a search on 17104288 on that site, but no luck. However, I did find that injector P/N listed correctly at this site for a '95 C3500:

http://www.tomco-inc.com/Catalog/24f...%20-%20tbi.pdf

In the end, though, neither one of these sites identifies the flow rate for the injectors...just the application.

That takes me back to using the "color code" approach, which still confuses me. The only color I can find on my injectors is the orange part at the base of each post where the connector plugs into the injector (see pic below). The only color code that mentions orange in your post is "Orange/Black 5.7L pickup 55 lb/hr GM 5235206 *RPD"...when it should be a "Blue/Black" combo for my 1995 big block pickup application.

What's up with the two color listing anyway? Are the injector base posts supposed to be different colors, such as one is orange and one is black, or two-tone on the same post, or something like that? If so, then my injectors are oddballs 'cause both base posts on both injectors are orange in color. Any ideas?

dimented24x7

iTrader: (2)

there should be dabs of paint on the plastic orange terminal posts. Those will give the color codes, assuming theyre still present.

badxs

the paint should be on the center (post, or protrusion) of the injector. ive got 4 sets and they all have the paint there. but sometimes its worn off,or very faded and allmost impassable to see.

11sORbust

This should be added to the, "Grumpy's final answer and important topics"