Going Stand Alone - Ford Mustang Forums : Corral.net Mustang Forum
 
LinkBack Thread Tools Display Modes
post #1 of 10 Old 09-01-2015, 01:59 PM Thread Starter
Registered User
 
Onequik89's Avatar
 
Trader Feedback: (10)
Join Date: Jun 2012
Location: Louisiana
Posts: 123
Going Stand Alone and Have Some Questions

Going to a stand alone system like the F.A.S.T. or Holley system very very soon in my 89 GT with a 331 EFI with a Vortech. I want to keep things like turn signals, horn, power windows, and power locks. My question is any of that controlled thru the stock ECU or can i pull the ECU and complete engine harness out or do i need to leave the ECU and part of the harness in the car? I know the power locks get their power from the solenoid but unsure about the rest.

Onequik89 is offline  
Sponsored Links
Advertisement
 
post #2 of 10 Old 09-01-2015, 04:08 PM
Corral Elite Member
 
Saleen414's Avatar
 
Trader Feedback: (2)
Join Date: Feb 2012
Location: Levant, Maine
Posts: 2,320
I run a Fast XFI on my car. The entire engine harness and ECU can be removed. None of the other electrical systems on the car are run by the ECU.


1989 Saleen 414 358cid SBF 2.8L Kenne Bell S/C
26 X 8.5 Hoosier
Best 1/4 mile time 8.623 @ 159.82 mph with a 1.34 60' (5.57 1/8th at 128)
Best 1/8 mile time 5.339 @ 133.46 mph with a 1.29 60'
08' Bullitt #4097 N/A 340ish RWHP <<<<<FOR SALE!
Saleen414 is online now  
post #3 of 10 Old 09-01-2015, 06:04 PM
Registered User
 
boostdcoupe's Avatar
 
Trader Feedback: (30)
Join Date: Jan 2010
Location: Jacksboro, Tn
Posts: 6,995
Garage
Quote:
Originally Posted by Saleen414 View Post
I run a Fast XFI on my car. The entire engine harness and ECU can be removed. None of the other electrical systems on the car are run by the ECU.
arent some of the stock gauges fed by the stock harness?

replaced the 93'ish coupe with a 76 F100, 393, 11.5:1, TEA CNC 205 TW's, custom Hyd Roller, Super Vic, 830 HP, AOD, Edge custom conv., Silverfox SPT-MAC-TB.
boostdcoupe is offline  
Sponsored Links
Advertisement
 
post #4 of 10 Old 09-02-2015, 07:06 AM Thread Starter
Registered User
 
Onequik89's Avatar
 
Trader Feedback: (10)
Join Date: Jun 2012
Location: Louisiana
Posts: 123
I'm putting in an electronic dash so im not too worried about the gauges. Yes some of them get readings from sensors on the motor.
Onequik89 is offline  
post #5 of 10 Old 09-02-2015, 08:16 AM
Registered User
 
TomR's Avatar
 
Trader Feedback: (2)
Join Date: Aug 2009
Location: Macon, GA
Posts: 4,960
Garage
I thought about connecting my OEM dash gauges, and I even built an interface board, but I decided to use the Holley digital dash.

I made a cluster with LED idiot lights that also has two red LED three digit displays instead. This way I still have a blue bright light, turn signal, and multiple warning light indicators.

My battery is on a large 3 digit meter and has a red or green LED above it. It is green when charging, blank when anything below charge voltage down to about 75% charge, and red when less than 50% charge.

I haven't decided what to use the second three digit display for. Likely water temperature or fuel.

I put 5 or 6 LED's (that can each be red, yellow, or green) across the center. They can be triggered from the Holley, or they can independently operate from the Holley sensors. They bridge the sensors with hundreds of thousands of ohms impedance, so they cannot affect sensor function.

I find warning lights much more effective than gauges, the only gauge I watch is a tach.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
89 LX. 363, single turbo, Super Vic EFI, TFS high port heads by TEA, solid roller, glide. Holley HP EFI. (exact combo varies)
TomR is offline  
post #6 of 10 Old 09-02-2015, 09:29 AM
Registered User
 
Trader Feedback: (0)
Join Date: Sep 2006
Location: Covington, Georgia
Posts: 1,597
Quote:
Originally Posted by boostdcoupe View Post
arent some of the stock gauges fed by the stock harness?
Yes, but the only one that ties into the engine controls is the tach, which gets a signal from the TFI module. If going distributorless, most ECUs have a tach output anyway.

The other gauges have separate sensors that do not tie into the ECU.

Matt Cramer
Matt Cramer is offline  
post #7 of 10 Old 09-02-2015, 04:24 PM
Corral Elite Member
 
Saleen414's Avatar
 
Trader Feedback: (2)
Join Date: Feb 2012
Location: Levant, Maine
Posts: 2,320
With the Fast XFI you have to run an aftermarket ignition box to trigger the ignition anyway. All of the aftermarket ignition boxes have a tach output. You would just take the tach wire from the stock harness and run it to the aftermarket box, just like you would do if you installed an MSD or other ignition box to a stock Mustang.
Also the Fast system uses GM ECT, ACT, and MAP sensors. The IAC is also different. Whatever you do, DO NOT power up the Fast system with the IAC disconnected. It WILL fry the Fast ECU. Sometimes it is only a $125 repair (plus shipping) other times you smoke the whole ECU. Ask me how I know.

1989 Saleen 414 358cid SBF 2.8L Kenne Bell S/C
26 X 8.5 Hoosier
Best 1/4 mile time 8.623 @ 159.82 mph with a 1.34 60' (5.57 1/8th at 128)
Best 1/8 mile time 5.339 @ 133.46 mph with a 1.29 60'
08' Bullitt #4097 N/A 340ish RWHP <<<<<FOR SALE!

Last edited by Saleen414; 09-02-2015 at 04:27 PM.
Saleen414 is online now  
post #8 of 10 Old 09-02-2015, 05:57 PM
Registered User
 
TomR's Avatar
 
Trader Feedback: (2)
Join Date: Aug 2009
Location: Macon, GA
Posts: 4,960
Garage
Quote:
Originally Posted by Saleen414 View Post
With the Fast XFI you have to run an aftermarket ignition box to trigger the ignition anyway. All of the aftermarket ignition boxes have a tach output. You would just take the tach wire from the stock harness and run it to the aftermarket box, just like you would do if you installed an MSD or other ignition box to a stock Mustang.
Also the Fast system uses GM ECT, ACT, and MAP sensors. The IAC is also different. Whatever you do, DO NOT power up the Fast system with the IAC disconnected. It WILL fry the Fast ECU. Sometimes it is only a $125 repair (plus shipping) other times you smoke the whole ECU. Ask me how I know.
Why on earth would disconnecting the IAC damage the FAST system? That makes no sense at all. If an open load damages it, they have a serious hardware design issue. A good system would be protected for shorts, but it really takes a big hardware error for an open port to cause damage.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
89 LX. 363, single turbo, Super Vic EFI, TFS high port heads by TEA, solid roller, glide. Holley HP EFI. (exact combo varies)
TomR is offline  
post #9 of 10 Old 09-03-2015, 06:42 AM Thread Starter
Registered User
 
Onequik89's Avatar
 
Trader Feedback: (10)
Join Date: Jun 2012
Location: Louisiana
Posts: 123
Quote:
Originally Posted by TomR View Post
Why on earth would disconnecting the IAC damage the FAST system? That makes no sense at all. If an open load damages it, they have a serious hardware design issue. A good system would be protected for shorts, but it really takes a big hardware error for an open port to cause damage.
I agree TomR. I do not see how an open load like an IAC will fry and ECU. The holley system you can run it with or without the IAC with no issues. Can you PM when you get some time please TomR? I have read thru your thread putting the Holley in and have some questions I'm sure you can help me with.
Onequik89 is offline  
post #10 of 10 Old 09-03-2015, 10:50 AM
Corral Elite Member
 
Saleen414's Avatar
 
Trader Feedback: (2)
Join Date: Feb 2012
Location: Levant, Maine
Posts: 2,320
Quote:
Originally Posted by TomR View Post
Why on earth would disconnecting the IAC damage the FAST system? That makes no sense at all. If an open load damages it, they have a serious hardware design issue. A good system would be protected for shorts, but it really takes a big hardware error for an open port to cause damage.
I asked this very same question. I was stunned that it was designed that way, but it is. I work on a lot of different makes of cars from around the world and if a car comes in with a high idle problem, one of the things I do is unplug the IAC while it is running to see if the high idle is being commanded by the ECU. It helps point me in the right direction with the diagnosis. I tried that with the Fast system and smoked the ECU. I called them about it, and they just said that is just the way it is, and Duh, don't do that again. I personally don't understand why anyone would design it that way. It makes no sense at all. Lucky for me it was a $125 repair, and I did not have to shell out the over $1K for a new ECU.


1989 Saleen 414 358cid SBF 2.8L Kenne Bell S/C
26 X 8.5 Hoosier
Best 1/4 mile time 8.623 @ 159.82 mph with a 1.34 60' (5.57 1/8th at 128)
Best 1/8 mile time 5.339 @ 133.46 mph with a 1.29 60'
08' Bullitt #4097 N/A 340ish RWHP <<<<<FOR SALE!
Saleen414 is online now  
Sponsored Links
Advertisement
 
Reply

Bookmarks

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Ford Mustang Forums : Corral.net Mustang Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
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:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



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

 
For the best viewing experience please update your browser to Google Chrome