Search



Go Back   MustangForums.com > Ford Mustang Tech > General Tech
Sign in using an external account
Register Forgot Password?
Search

General Tech Ask model specific questions in the appropriate category below. All other general questions within.
Sponsored by NewTakeOff


Welcome to Mustang Forums!
Welcome to Mustang Forums.

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, so please join our community today!


Reply
 
 
 
 
Thread Tools Search this Thread
Old 01-14-2013, 10:31 PM   #1
86GT40_TireShreader
 
Join Date: Jan 2013
Vehicle: 1986, Ford, Mustang GT
Location: Virginia
Posts: 3
Default 86 Mustang GT will not idle

I have an 86 GT that will not idle until it warms up. It had the same problem before I did the mass air conversion. Ive replaced the tps, oxygen sensors, idle air motor, temp sensor, maniforl air temp sensor, all new vaccum lines, egr block off. It has GT40 heads and intakes, trick flow stage 1 cam. I set the timing at 18 deg, bc its high compression, it has good spark new plugs and Ford Racing 8mm wires. Runs perfect and tons of power once its at operating temp. The map sensor is still hooked in the system but the vaccum port is capped like the kit instructed. I dont know if the map sensor could be bad and still effecting it or not. Could it be the wiring? Im out of ideas after that. This thing is driving me nuts, any help at all would be awesome.
This ad is not displayed to registered or logged-in members.
Register your free account today and become a member on Mustang Forums!
86GT40_TireShreader is offline   Reply With Quote
Old 01-15-2013, 12:15 AM   #2
go-part
Former Sponsor
 
Join Date: Nov 2012
Vehicle: 2000 ford mustang
Location: CA
Posts: 133
Default

Have you tried the KOEO - Key On Engine Off Self Test? It may help you pinpoint your problem
http://dfwmustangs.net/forums/showthread.php?t=7908
go-part is offline   Reply With Quote
Old 01-15-2013, 07:08 PM   #3
Mike T
2nd Gear Member

 
Mike T's Avatar
 
Join Date: Nov 2012
Vehicle: 1989 Ford Mustang GT
Location: Mississippi
Posts: 313
Default

Quote:
Originally Posted by 86GT40_TireShreader View Post
I have an 86 GT that will not idle until it warms up. It had the same problem before I did the mass air conversion. Ive replaced the tps, oxygen sensors, idle air motor, temp sensor, maniforl air temp sensor, all new vaccum lines, egr block off. It has GT40 heads and intakes, trick flow stage 1 cam. I set the timing at 18 deg, bc its high compression, it has good spark new plugs and Ford Racing 8mm wires. Runs perfect and tons of power once its at operating temp. The map sensor is still hooked in the system but the vaccum port is capped like the kit instructed. I dont know if the map sensor could be bad and still effecting it or not. Could it be the wiring? Im out of ideas after that. This thing is driving me nuts, any help at all would be awesome.
Do this, the base idle reset...http://www.muscularmustangs.com/idlereset.php
__________________
TFS Streetburner intake, TFS 70mm t/b, BBK ceramic L/T's, BBK h-pipe, Flowmaster 44's, C&L 76mm cai/maf, 24# injectors, Walbro 255lph, 3:55 gears, Weld draglite rims, BBK c/c plates..."Gimme back my bullets, put em back where they belong"-Lynyrd Skynyrd
Mike T is offline   Reply With Quote
Old 01-16-2013, 11:26 PM   #4
86GT40_TireShreader
 
Join Date: Jan 2013
Vehicle: 1986, Ford, Mustang GT
Location: Virginia
Posts: 3
Default

I have already done the idle reset and it had no effect. I haven't tried the KOEO test yet. Thanks tho. One thing I forgot about was the car is loading up on fuel bad, running super rich until it reaches operating temp too. Thanks for the input guys. I borrowed a running functional fuel rail with injectors and regulator. A friend told me I may have an injector stuck open may be causing my problem, so thats the next thing Im going to try.
86GT40_TireShreader is offline   Reply With Quote
Old 01-17-2013, 04:07 AM   #5
Mike T
2nd Gear Member

 
Mike T's Avatar
 
Join Date: Nov 2012
Vehicle: 1989 Ford Mustang GT
Location: Mississippi
Posts: 313
Default

Quote:
Originally Posted by 86GT40_TireShreader View Post
I have already done the idle reset and it had no effect. I haven't tried the KOEO test yet. Thanks tho. One thing I forgot about was the car is loading up on fuel bad, running super rich until it reaches operating temp too. Thanks for the input guys. I borrowed a running functional fuel rail with injectors and regulator. A friend told me I may have an injector stuck open may be causing my problem, so thats the next thing Im going to try.
Coolant temp sensor could be the problem.{edit} seen your original post ,you already changed it.
__________________
TFS Streetburner intake, TFS 70mm t/b, BBK ceramic L/T's, BBK h-pipe, Flowmaster 44's, C&L 76mm cai/maf, 24# injectors, Walbro 255lph, 3:55 gears, Weld draglite rims, BBK c/c plates..."Gimme back my bullets, put em back where they belong"-Lynyrd Skynyrd

Last edited by Mike T; 01-17-2013 at 04:12 AM.
Mike T is offline   Reply With Quote
Old 01-17-2013, 11:25 PM   #6
capri debris
3rd Gear Member
 
capri debris's Avatar
 
Join Date: Nov 2006
Vehicle: 1986 Mercury Capri
Location: PA
Posts: 816
Default

Things to consider after pulling codes and correcting any problems that it shows:

1. Fuel pressure regulator not set correctly.

2. Throttle position senser not set correctly.

3. Mass air meter dirty or not calibrated correctly for the size injectors you have.

4. Salt & pepper connectors at the center of the firewall need cleaned.

5. Vehicle speed sensor not wired properly to new ECU when you converted to mass air.

6. Poor ECU ground.

7. Vacuum leaks.

8. Bad EGR.
__________________
'86 Mercury Capri 5.0, 5 spd, mildly modded.
capri debris is offline   Reply With Quote
Old 01-30-2013, 09:04 PM   #7
86GT40_TireShreader
 
Join Date: Jan 2013
Vehicle: 1986, Ford, Mustang GT
Location: Virginia
Posts: 3
Default

The great mystery is finally solved!! I got a test light and pulled the codes and that led me in the right direction of which wires to check. Number46 from the ecm goes to the TPS, EGR, MAP, IAT, CTS, and the self test plug, and found that the MAP sensor was left out. I didnt think it would matter since I did a mass air conversion but it does. I skinned the wire and ran it the same sharred lug from the EGR and the SOB fired right up the idle smoothed out and it didnt load up on fuel. Thanks guys for the help.
86GT40_TireShreader is offline   Reply With Quote
Old 01-30-2013, 09:04 PM
MustangForums
Ford Mustang




Paid Advertisement

 
 
 
Reply

Tags
1986, 5.0, idle

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

Forum Jump

Advertising

Featured Sponsors
Vendor Directory
New Sponsors
All times are GMT -5. The time now is 07:49 PM.

© Internet Brands, Inc.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Friendly URLs by vBSEO 3.5.2

This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. Ford® is a registered trademark of the Ford Motor Company
Emails Backup