TPI Programming with wrong sized injectors referenced. - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 01-02-2008, 07:53 PM
Registered User
 

Last journal entry: Oil Leaks and Nobody said look for ...
Last photo:
Join Date: Feb 2005
Location: Anoka, MN
Posts: 19
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
TPI Programming with wrong sized injectors referenced.

Hi Hotrodders,

I ordered a programming service for my TPI system. My TPI system is off a 305 but the engine is a 355. I told the programmer that I was using 24 lbs. injectors but I discovered that I am actually using 22 lbs. injectors. How big of a deal is this error? I am using an adjustable fuel pressure regulator. Can I use the fuel pressue regulator to compensate for my programming error? Or is it a non-issue?

Thanks in Advance,

ericbr

Last edited by ericbr; 01-02-2008 at 08:16 PM. Reason: grammar
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 01-02-2008, 08:50 PM
carsavvycook's Avatar
My 2 cents worth
 
Last photo:
Join Date: Sep 2007
Location: Lakeside, CA
Age: 57
Posts: 2,855
Wiki Edits: 3

Thanks: 2
Thanked 2 Times in 2 Posts
I have yet to use one of these programmer's. Is it re-writable? It will effect the on-time of the injector referenced to the pressure given not available pressure. By doing so in your case it will keep the on-time shorter for a 24psi pressure given injector, leaning out your injection. This will be the same regardless of the mechanical pressure you have.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 01-02-2008, 08:52 PM
Member
 
Join Date: Dec 2004
Location: Madison, WI
Posts: 1,885
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Had to rewrite the post as I read your post backwards. Short answer, I don't think you'll have an problems. I suspect the tune will be slightly rich as delivered, based on what I have seen on chips in the past.

Last edited by Rick WI; 01-02-2008 at 09:31 PM.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 01-03-2008, 12:25 PM
Registered User
 
Last photo:
Join Date: Apr 2007
Location: Seattle, Wa
Posts: 6,434
Wiki Edits: 0

Thanks: 3
Thanked 331 Times in 288 Posts
Quote:
Originally Posted by ericbr
Hi Hotrodders,

I ordered a programming service for my TPI system. My TPI system is off a 305 but the engine is a 355. I told the programmer that I was using 24 lbs. injectors but I discovered that I am actually using 22 lbs. injectors. How big of a deal is this error? I am using an adjustable fuel pressure regulator. Can I use the fuel pressue regulator to compensate for my programming error? Or is it a non-issue?

Thanks in Advance,

ericbr
Probably a non issue, but yes, you can tune this with the pressure regulator.

Bogie
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 01-04-2008, 04:13 PM
Siggy_Freud's Avatar
Hotrodders.com Moderator
 
Last photo:
Join Date: Dec 2003
Location: Portland, Oregon
Age: 29
Posts: 2,371
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
If anything, I imagine you'll want to turn the fuel pressure up a bit. If the computer thinks you have 24lb injectors, it will fire them for a shorter period than if you had 22lb injectors. By increasing the pressure slightly, you'll pump in more fuel during that shorter fire (duty) cycle.

This is all assuming the tune is pretty spot on. Like was mentioned, tunes tend to come rich, as the problems/symptoms with a rich tune tend to be less noticable and damaging than a lean tune.

What type of programming setup did you go with?
__________________
Bringing history and technology together.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 01-07-2008, 10:49 AM
Registered User
 

Last journal entry: Oil Leaks and Nobody said look for ...
Last photo:
Join Date: Feb 2005
Location: Anoka, MN
Posts: 19
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
What type of programming did I go with?

I am using a piggy back approach. I use the stock GM PROM with the prepared chip sandwiched between the stock PROM and the computer. The programmer than puts my specs into this adapter piece.

I pretty much went with the stock specs except fan temps on-195, off 180. I am using the EGR but not the air pump, redline 5800, speed limit 155, using cold start, no VATS, and injectors 24-lbs.

Thanks for your interest and reply,

ericbr
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 01-07-2008, 02:33 PM
Siggy_Freud's Avatar
Hotrodders.com Moderator
 
Last photo:
Join Date: Dec 2003
Location: Portland, Oregon
Age: 29
Posts: 2,371
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
The stock PROM is kept because it retains the "Limp home mode". If something goes wrong and it kicks and engine light, the computer jumps over to the stock chip for safety mode. I am very familiar with this setup. I imagine your chip is a flash burned chip too, instead of a UV chip (as most UV setups dont require an adapter).
__________________
Bringing history and technology together.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may 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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
TBI Injectors vs TPI Injectors Junorr Electrical 3 09-02-2004 10:35 PM


All times are GMT -6. The time now is 08:29 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.