fuel pump wont prime
03-04-2010, 09:21 PM
#1
3rd Gear Member
Thread Starter
Join Date: Sep 2008
Location: Bel Air, MD
Posts: 599
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?
what could it be?
03-04-2010, 10:52 PM
#3
D.R. THE PATHETIC DORK
Join Date: Jun 2007
Location: West Virginia
Posts: 30,863
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
03-04-2010, 10:56 PM
#4
3rd Gear Member
Thread Starter
Join Date: Sep 2008
Location: Bel Air, MD
Posts: 599
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.
03-04-2010, 11:01 PM
#5
D.R. THE PATHETIC DORK
Join Date: Jun 2007
Location: West Virginia
Posts: 30,863
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
03-04-2010, 11:09 PM
#6
3rd Gear Member
Thread Starter
Join Date: Sep 2008
Location: Bel Air, MD
Posts: 599
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
03-04-2010, 11:47 PM
#9
5th Gear Member
Join Date: Feb 2006
Location: Southwest VA.
Posts: 3,915
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.
03-04-2010, 11:48 PM
#10
D.R. THE PATHETIC DORK
Join Date: Jun 2007
Location: West Virginia
Posts: 30,863
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