GM TBI Throttle bodies, Injectors, Color Codes, and Flow Rates

[T Man]

TBI throttle body and injector information

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

Application Throttle bore size Injector color code Flow rate Part #

2.8l v6 1-3/8" Black/White 35 lb/hr GM 5235430 *RPD

4.3L 1-13/16" Yellow/Blue 45 lb/hr GM 5235203 *RPD

5.0L 1-13/16" Green/White 40 lb/hr GM 5235279 *RPD

5.7L pickup 1-13/16" Orange/Black 55 lb/hr GM 5235206 *RPD

5.7L Cop Car 1-13/16" Yellow/Brown 65 lb/hr 17084327-ACR

Late big block pickup 2" Blue/Black 80 lb/hr GM 1708430 *RPD

big block pickup 2" Dark Red/Dark Blue 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. Mismatched 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

* New service package Part Number 17111928
* Remanufactured equivalent Part Number 17111930

TPS Side Bore COLOR-CODED PINK AND BROWN

* New service package Part Number 17111929
* Remanufactured equivalent Part Number 17111931



All information taken driectly from http://groups.msn.com/AutoTechsOnline/knownfixesforgm.msnw?action=view_list&viewtype=0&sortstring=2a1d thank you very much for the detaled information.

[KRUZER1]

good information but none of the pictures down at the bottom would show up, even if i tried to open them in a new window, anyone else have that problem?

[T Man]

yup, thats the reason that they arent posted. Do you have a specific question? Sparky knows, ive got a little bit of experience taking them apart and putting them back togther

[Matt 4.3 TBI]

I actually posted the flow rates at the old Planet, and they were reposted here quite a while ago :D

http://www.sicgmtrucks.com/forum/showthread.php?t=269

[T Man]

Dunno if it was stuck before, but it is now. Thanks Matt

[KRUZER1]

no i was just looking, i used to work for Dr. Injector in Redmond WA, learned a good amount there about flow rates and whatnot but it nice to have specific info. I just like pictures thats all.

[tizzy]

no love for the 2.2's? oh well, there worthless anyways

[KRUZER1]

I actually posted the flow rates at the old Planet, and they were reposted here quite a while ago :D

http://www.sicgmtrucks.com/forum/showthread.php?t=269

thats a whole lot of good info. (didnt read it till after my last post sorry)
you said that all 92 and up engines have an internal balance shaft, ive heard about the vibration in 88-91 engines, is it an unbalanced engine, where is the vibration coming from, if i remember mine was the worst at 1300 RPM's. i had a 89 from an S10 now i have an 88 from an astro, both have or have had the vibration.

[Sparky2263]

It's not that it's unbalanced but rather the inherent imbalance in a V-6. The balance shaft (which is an EXTREMELY unbalanced piece) cancels out those imbalances. I disconnected mine. Vibrates like a pre-92. No biggie.

[T Man]

no love for the 2.2's? oh well, there worthless anyways


They never had a Throttle body injection on a 2.2, so yes turtle, no love

[KODIAKWARRIOR]

so sparky, is that what that balance shaft does under the intake manifold on a 2003 4.3 liter?? i was taking mine off getting it ready for a carb and wondered what the heck it was, never seen one before.

[Sparky2263]

That's what it's for. Very dangerous piece of cast metal for those of us that like to spin 'em up. Here's a pic of the ugly critter.

The ones I've unhooked I just took the front gear off and left the shaft in place. There's 2 oil passages you'd have to plug if you removed it.

http://www.sicgmtrucks.com/forum/attachment.php?attachmentid=1663&stc=1

http://www.sicgmtrucks.com/forum/attachment.php?attachmentid=1664&stc=1

[KODIAKWARRIOR]

yea im trying to take a 4.3 liter form a 03 s-10 and drop a carb and distributor and all that good stuff on it, getting away from the eelctronic stuff, and of course its going to see its fare share of racing, to that rod is leaving my engine. thanks sparky for clarifying that for me.

[KRUZER1]

That's what it's for. Very dangerous piece of cast metal for those of us that like to spin 'em up. Here's a pic of the ugly critter.

The ones I've unhooked I just took the front gear off and left the shaft in place. There's 2 oil passages you'd have to plug if you removed it.

That is one seriously ugly shaft!! i think that i would deal with the vibration before turning that inside my motor. thanks for the info cause i was curious if i tore my whole engine down and bored, and balanced everything if it would still vibrate. think it would? keep in mind its an 88.

[Sparky2263]

Yup. It's an inherent vibration. It's kinda cool cause when you've got the motor running it shakes a bit looking like a bigger cam than it really is.

Always something to be said for the cool factor. ;)

[KRUZER1]

Yup. It's an inherent vibration. It's kinda cool cause when you've got the motor running it shakes a bit looking like a bigger cam than it really is.

Always something to be said for the cool factor. ;)

wurd

[chesspirate]

I've always heard that the early ones were shakers but i've got a 91 and i don't seem to have much (if any) vibration above almost every other vehicle pre 2000, did i just get lucky?

[Nickelin'Dimer]

Uh, wasn't this an injector thread, and what are the flow-rates for the 2.5's?