93 GT Fuel pump not priming

Busa1300

New Member
Jul 22, 2011
14
0
1
So my car was running fine and then I parked it for a few months. The next time I tried to drive it I couldn't get it to start. It would crank.just fine but not start. Then I noticed the fuel pump would not prime when I turned the key on. So I replaced the relay didn't fix it. Then I checked the fuses link had power. I used a jumper wire at the test port and at the relay. And the pump comes on both ways. I even tried to fill the lines full of fuel by jumping it. And then figured if i cranked it maybe it would at least pop off for a sec since the fuel lines were full. But it didnt do anything. So then I replaced the relay by the ECU and that didn't fix it. I then though it was a ground issue. So I found the wire #22 on the ECU and grounded it to the frame. And when I turned the key on the pump came on but stayed on. I figured that is because it had a constant ground. So I figured it was the ECU. So I sent it to ECU EXCHANGE to get rebuilt. That still didn't fix it. So I checked the ignition switch. When I unplugged the switch the wire harness fell apart in my hand. Looks like it got hot at some point. So I ordered a new harness pigtail. I replaced the pig tail and the ignition switch. And that still didn't fix it. So now I am completely freaking lost. I and about to start back over. I have all the diagrams for the system. I am going to start at the ignition switch and go from there. Does anyone have any other suggestions?
 
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manicmechanic007

Mustang Master
Sep 26, 2017
1,553
438
93
62
What year is it?
The ecu controls the ground circuit of the fuel pump relay
So does it run if you jump the two wires in the self test connector?
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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manicmechanic007

Mustang Master
Sep 26, 2017
1,553
438
93
62
It's a bit late for the checklist
And then there is the breakout box
Is that in the checklist?
Pinpoint tests Q also in there?
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
22,757
8,253
203
polk county florida
It's a bit late for the checklist
And then there is the breakout box
Is that in the checklist?
Pinpoint tests Q also in there?
are you questioning the validity of the checklist?
and why is it a bit late?
these are questions to be discussed in another thread, we are here to help this member find and fix his issue(s). Talking about the 'breakout box' is meaningless mostly because the member does not have one or likely to run out and buy one.
The 'list' was put together by jrichker (with help from other members), who has been around stangnet for over 20 years and is 'stangnet's favorite tool'.
I personally will guarantee if the member follows the checklist, barring an underlying issue unknown to us, it will find the problem and help fix it.
 

manicmechanic007

Mustang Master
Sep 26, 2017
1,553
438
93
62
It is late because he has replaced half the car already
The checklist.. I have not even checked but am sure there are no pinpoint tests in there
Correct me if I am wrong
What does it say to do with a code 15 or 18
I am assuming it is generic info not worth my read is all
 

Busa1300

New Member
Jul 22, 2011
14
0
1
What year is it?
The ecu controls the ground circuit of the fuel pump relay
So does it run if you jump the two wires in the self test connector?
It is a 93! Yes the fuel pump does run when I jump it at the self test connector. The pump also runs when I jump it at the relay
 

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor
Admin Dude
Jan 4, 1985
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Box behind Walmart
www.stangnet.com
It is late because he has replaced half the car already
The checklist.. I have not even checked but am sure there are no pinpoint tests in there
Correct me if I am wrong
What does it say to do with a code 15 or 18
I am assuming it is generic info not worth my read is all

Well, you know what they say about assumptions. Why not run the checklist and find out?
 
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manicmechanic007

Mustang Master
Sep 26, 2017
1,553
438
93
62
Alrighty then
I know there is no I in Team Ford but
I simply do not need to read any checklist myself for any Foxbody mustang or any other ford unless it is real new
I have read thousands
I can figure those out in 5 minutes with my tools and experience and only read service literature on the ones I need to
I go to the library once a week at least for info
I know my way around Ford pinpoint tests and I own a 60 pin breakout box and a NGS comma
Super Star II and several pressure gauges and fuel injection test equipment injector cleaners
Unless written by the manufacture I have little use for service literature
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
22,757
8,253
203
polk county florida
Alrighty then
I know there is no I in Team Ford but
I simply do not need to read any checklist myself for any Foxbody mustang or any other ford unless it is real new
I have read thousands
I can figure those out in 5 minutes with my tools and experience and only read service literature on the ones I need to
I go to the library once a week at least for info
I know my way around Ford pinpoint tests and I own a 60 pin breakout box and a NGS comma
Super Star II and several pressure gauges and fuel injection test equipment injector cleaners
Unless written by the manufacture I have little use for service literature
:doh:
 
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General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
22,757
8,253
203
polk county florida
So my car was running fine and then I parked it for a few months. The next time I tried to drive it I couldn't get it to start. It would crank.just fine but not start. Then I noticed the fuel pump would not prime when I turned the key on. So I replaced the relay didn't fix it. Then I checked the fuses link had power. I used a jumper wire at the test port and at the relay. And the pump comes on both ways. I even tried to fill the lines full of fuel by jumping it. And then figured if i cranked it maybe it would at least pop off for a sec since the fuel lines were full. But it didnt do anything. So then I replaced the relay by the ECU and that didn't fix it. I then though it was a ground issue. So I found the wire #22 on the ECU and grounded it to the frame. And when I turned the key on the pump came on but stayed on. I figured that is because it had a constant ground. So I figured it was the ECU. So I sent it to ECU EXCHANGE to get rebuilt. That still didn't fix it. So I checked the ignition switch. When I unplugged the switch the wire harness fell apart in my hand. Looks like it got hot at some point. So I ordered a new harness pigtail. I replaced the pig tail and the ignition switch. And that still didn't fix it. So now I am completely freaking lost. I and about to start back over. I have all the diagrams for the system. I am going to start at the ignition switch and go from there. Does anyone have any other suggestions?
tracing power from the ignition switch is a good start, I'm kinda backwards, I would start at the inertia switch checking for power and go backwards from there,
 

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor
Admin Dude
Jan 4, 1985
32,902
14,771
234
Box behind Walmart
www.stangnet.com
Alrighty then
I know there is no I in Team Ford but
I simply do not need to read any checklist myself for any Foxbody mustang or any other ford unless it is real new
I have read thousands
I can figure those out in 5 minutes with my tools and experience and only read service literature on the ones I need to
I go to the library once a week at least for info
I know my way around Ford pinpoint tests and I own a 60 pin breakout box and a NGS comma
Super Star II and several pressure gauges and fuel injection test equipment injector cleaners
Unless written by the manufacture I have little use for service literature
You should publish a book and collect that mad cash. :shrug:
 
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