Search



Go Back   MustangForums.com > Ford Mustang Tech > 5.0L (1979-1995) Mustang
Sign in using an external account
Register Forgot Password?
Search

5.0L (1979-1995) Mustang Technical discussions on 5.0 Liter Mustangs within. This does not include the 5.0 from the 2011 Mustang GT. That information is in the 2005-1011 section.

Sponsored by Weld Racing


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 03-04-2010, 09:21 PM   #1
AYEOH5.0
3rd Gear Member
 
Join Date: Sep 2008
Vehicle: 1989 Mustang GT
Location: Bel Air, MD
Posts: 599
Default fuel pump wont prime

drove the car almost a 100 miles on monday, then drove it home and parked it. i drove my truck until today, but i had a job interview at a ford dealership and wanted to take my mustang to show them i am capable of working on automobiles and i tried starting it and it wont start. so i checked the fuel pressure and its at zero. i tried to start it again and noticed i dont hear the fuel pump prime. the car has literally not moved since the last time i drove it.

what could it be?
This ad is not displayed to registered or logged-in members.
Register your free account today and become a member on Mustang Forums!
__________________
1989 Mustang GT - 347 stroker (sold)
2002 Mustang GT - V2 S-Trim 429hp 413tq
AYEOH5.0 is offline   Reply With Quote
Old 03-04-2010, 09:40 PM   #2
AdderMk2
Banned
 
Join Date: Dec 2005
Vehicle: 94 Cobra
Location: Lil' Rhody
Posts: 22,376
Send a message via AIM to AdderMk2
Default

check the FP relay, see if it clicks, check the inertia switch... I like hitting peoples tail lights to trip them.

and if those get you no where, unplug your ECM, it should kick on instantly
AdderMk2 is offline   Reply With Quote
Old 03-04-2010, 10:52 PM   #3
mjr46
Wal-mart lube/tire tech
 
mjr46's Avatar
 
Join Date: Jun 2007
Vehicle: 85 mustang
Location: West Virginia
Posts: 29,735
Default

go back to the fp plug behind the bumper and prob the power wire with a test light while someone pulses the key on , if it briefly lights the test light and ground is good, = safe to say pump went south
__________________

Quote:
Originally Posted by dudegirl View Post
Be polite and cordial when you talk to them, as pissing off the guys that can help you is seldom a good idea.
mjr46 is offline   Reply With Quote
Old 03-04-2010, 10:56 PM   #4
AYEOH5.0
3rd Gear Member
 
Join Date: Sep 2008
Vehicle: 1989 Mustang GT
Location: Bel Air, MD
Posts: 599
Default

why would the pump all of a sudden go bad? and i checked the interia switch, that was the first thing i checked. how can i check the relay? i know where it is i just dont know how to test it.
__________________
1989 Mustang GT - 347 stroker (sold)
2002 Mustang GT - V2 S-Trim 429hp 413tq
AYEOH5.0 is offline   Reply With Quote
Old 03-04-2010, 11:01 PM   #5
mjr46
Wal-mart lube/tire tech
 
mjr46's Avatar
 
Join Date: Jun 2007
Vehicle: 85 mustang
Location: West Virginia
Posts: 29,735
Default

they just do....happens many times, or what you can do, grab a rubber mallet and smack on the tank while someone cranks the car over, I've gotten many to start that way due to worn/faulty contacts in the pump windings, personally I like to work from the back to the front, if you go back to the pump harness and do the test I state and it powers up via lighting the test light up, no need to diagnose the fuel system any further as it's working properly and it's the load consumer that is bad = pump, the connector should be easily visible close to the back of the right side tank strap
__________________

Quote:
Originally Posted by dudegirl View Post
Be polite and cordial when you talk to them, as pissing off the guys that can help you is seldom a good idea.
mjr46 is offline   Reply With Quote
Old 03-04-2010, 11:09 PM   #6
AYEOH5.0
3rd Gear Member
 
Join Date: Sep 2008
Vehicle: 1989 Mustang GT
Location: Bel Air, MD
Posts: 599
Default

Quote:
Originally Posted by mjr46 View Post
they just do....happens many times, or what you can do, grab a rubber mallet and smack on the tank while someone cranks the car over, I've gotten many to start that way due to worn/faulty contacts in the pump windings, personally I like to work from the back to the front, if you go back to the pump harness and do the test I state and it powers up via lighting the test light up, no need to diagnose the fuel system any further as it's working properly and it's the load consumer that is bad = pump, the connector should be easily visible close to the back of the right side tank strap
ive actually already tried the mallet idea, guy at the ford dealership suggested it, o well if it is on its way out, time to get my 255 pump and run some boost!
__________________
1989 Mustang GT - 347 stroker (sold)
2002 Mustang GT - V2 S-Trim 429hp 413tq
AYEOH5.0 is offline   Reply With Quote
Old 03-04-2010, 11:13 PM   #7
mjr46
Wal-mart lube/tire tech
 
mjr46's Avatar
 
Join Date: Jun 2007
Vehicle: 85 mustang
Location: West Virginia
Posts: 29,735
Default

WELL THEN CHECK FOR POWER BACK AT THE PUMP = 2 min job
__________________

Quote:
Originally Posted by dudegirl View Post
Be polite and cordial when you talk to them, as pissing off the guys that can help you is seldom a good idea.
mjr46 is offline   Reply With Quote
Old 03-04-2010, 11:17 PM   #8
AYEOH5.0
3rd Gear Member
 
Join Date: Sep 2008
Vehicle: 1989 Mustang GT
Location: Bel Air, MD
Posts: 599
Default

Quote:
Originally Posted by mjr46 View Post
WELL THEN CHECK FOR POWER BACK AT THE PUMP = 2 min job
i will in the morning. if im not getting a blip, what do i check next?
__________________
1989 Mustang GT - 347 stroker (sold)
2002 Mustang GT - V2 S-Trim 429hp 413tq
AYEOH5.0 is offline   Reply With Quote
Old 03-04-2010, 11:47 PM   #9
ikeybmg
5th Gear Member
 
Join Date: Feb 2006
Location: Southwest VA.
Posts: 3,915
Default

FP will go out instantly like that sometimes. Mine in my truck just did awhile back. Check the relays and inertia switch like has done ben said. Could be the crank sensor also. Don't forget to check it.
__________________

347 stroked out GT, times TBA!
ikeybmg is offline   Reply With Quote
Old 03-04-2010, 11:48 PM   #10
mjr46
Wal-mart lube/tire tech
 
mjr46's Avatar
 
Join Date: Jun 2007
Vehicle: 85 mustang
Location: West Virginia
Posts: 29,735
Default

the relay under the seat, there should be 12v to the relay coil and the ecm controls the ground for the relay windings to be pulled in via the pip signal, by pulsing the key if relay is working you should feel it click on then off after 2 sec in that short period if you here it click put the test light on the load carring wire that goes back to the pump coming out of the relay, if it clicks but doesn't transfer power across the contacts = bad relay you'll need a wiring diagram of the system to probe the proper wires
__________________

Quote:
Originally Posted by dudegirl View Post
Be polite and cordial when you talk to them, as pissing off the guys that can help you is seldom a good idea.
mjr46 is offline   Reply With Quote
Old 03-04-2010, 11:48 PM
MustangForums
Ford Mustang




Paid Advertisement

 
 
 
Reply

Tags
1985, 50, dont, electric, ford, forum, fuel, hear, location, mustang, prime, pump, relay, time, wire, wont

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 06:31 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