Go Back   Third Generation F-Body Message Boards > Tech Boards > TBI
Sign in using an external account
Register Forgot Password?

TBI Throttle Body Injection discussion and questions. L03/CFI tech and other performance enhancements.

Welcome to ThirdGen.org!
Welcome to ThirdGen.org.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, join the ThirdGen.org community today!


Reply
 
Thread Tools Search this Thread
Old 06-23-2007, 10:21 PM   #1
Member
 
escort_ford84's Avatar
 
Join Date: Jun 2006
Posts: 148

Classifieds Rating: (0)
stock L03 TBI fuel pressure question

Im running a 1988 camaro TBI L03 w/mods. Injectors were going static @ 4 grand (I tune and burn my own chips). I went in and changed the regulator spring from stock to a TPI regulator spring and made it adjustable. With the adjustment all the way down, my fuel pressure is right at 28 PSI. Is this pressure ok or is it too much for TBI? I ran it a tad and there is no leaks. I know the big block tbi's run at like 18-20 PSI. I know i need bigger injectors, but this will have to do till i get them.

Thanks,
Michael
escort_ford84 is offline vBGarage Page   Reply With Quote
Old 06-23-2007, 10:28 PM   #2
Supreme Member
 
Join Date: Jan 2005
Location: Hurst, Texas
Posts: 5,958
Car: 1983 G20 Chevy
Engine: 305 TPI
Transmission: 4L60
Axle/Gears: 14 bolt with 3.07 gears

Classifieds Rating: (2)
Re: stock L03 TBI fuel pressure question

Quote:
Originally Posted by escort_ford84 View Post
Im running a 1988 camaro TBI L03 w/mods. Injectors were going static @ 4 grand (I tune and burn my own chips). I went in and changed the regulator spring from stock to a TPI regulator spring and made it adjustable. With the adjustment all the way down, my fuel pressure is right at 28 PSI. Is this pressure ok or is it too much for TBI? I ran it a tad and there is no leaks. I know the big block tbi's run at like 18-20 PSI. I know i need bigger injectors, but this will have to do till i get them.

Thanks,
Michael
I know that my Marine TBI regulator was setup to run at 30 PSI of fuel pressure. If your regulator diaphram is fresh as well as the O-rings, 35-40 PSI is not out of the question. If you plan to exceed 45 PSI, you need to block off the stock GM regulator and go to an external EFI bypass type regulator.
Fast355 is offline vBGarage Page   Reply With Quote
Old 06-24-2007, 12:32 AM   #3
Member
 
escort_ford84's Avatar
 
Join Date: Jun 2006
Posts: 148

Classifieds Rating: (0)
Re: stock L03 TBI fuel pressure question

Hey thanks man. Ill keep it like it is and tune it now.
escort_ford84 is offline vBGarage Page   Reply With Quote
Old 06-30-2007, 11:30 PM   #4
Member
 
escort_ford84's Avatar
 
Join Date: Jun 2006
Posts: 148

Classifieds Rating: (0)
Re: stock L03 TBI fuel pressure question

Im not a complete moron (lol) but.... could someone check my math? Im having trouble with the BPW. For some reason my car is running horrible at light throttle. Injector is the *279* (L03). Original fuel pressure was around 12 psi. my new fuel pressure is 28 psi. I come up with an Equiv. injector of #76 (76.37 flowrate). I came up with a 102 BPW. This is a L03 engine that i shift @ 6500 rpms. i posted this in the wrong thread, i cant figure out how to fix this.

Last edited by escort_ford84; 07-01-2007 at 03:20 AM.
escort_ford84 is offline vBGarage Page   Reply With Quote
Old 07-01-2007, 09:20 AM   #5
Moderator
 
Join Date: Mar 2002
Location: Chasing Electrons
Posts: 11,386
Car: check
Engine: check
Transmission: check

Classifieds Rating: (1)
Re: stock L03 TBI fuel pressure question

I typically use 13 psi for the base flow rate. For those injectors (55 #/hr) at 28 psi they will flow about 80.7 #/hr for a BPC of 90 and an engine CI of 305.

For the light throttle issue, is it surging? You may need to reduce the proportional gains, and slow down the INT update rate some.

RBob.
RBob is offline vBGarage Page   Reply With Quote
Old 07-01-2007, 03:35 PM   #6
Member
 
escort_ford84's Avatar
 
Join Date: Jun 2006
Posts: 148

Classifieds Rating: (0)
Re: stock L03 TBI fuel pressure question

thanks RBob.
escort_ford84 is offline vBGarage Page   Reply With Quote
Old 07-02-2007, 12:11 AM   #7
Member
 
escort_ford84's Avatar
 
Join Date: Jun 2006
Posts: 148

Classifieds Rating: (0)
Re: stock L03 TBI fuel pressure question

i set my BPW to 90 and its running MUCH better. Thanks again RBob.
escort_ford84 is offline vBGarage Page   Reply With Quote
Old 07-02-2007, 12:11 AM
ThirdGen
1992 Camaro




Paid Advertisement


Reply

Go Back   Third Generation F-Body Message Boards > Tech Boards > TBI

Tags
18, 1991, 1997, camaro, chevy, fuel, marine, mod, pickup, pressure, psi, rating, spring, stock, tbi
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 


1982 Camaro '82 || 1983 Camaro '83 || 1984 Camaro '84 || 1985 Camaro '85 || 1986 Camaro '86 || 1987 Camaro '87 || 1988 Camaro '88 || 1989 Camaro '89 || 1990 Camaro '90 || 1991 Camaro '91 || 1992 Camaro '92


All times are GMT -5. The time now is 08:24 PM.


Powered by vBulletin® Version 3.7.5
Copyright ©2000 - 2012, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.5.2
All content copyright © 1997 - 2012 ThirdGen.org. All rights reserved. No part of this website may be reproduced without the expressed, documented, and written consent of ThirdGen.org's Administrators.

Emails & Contact Details