FE Build 1989 5.0 won't start when hot except when using starting fluid

jrichker · Dec 25, 2020

$wine said:
34 and 44 would make sense as my smog pump and egr are both deleted. As for 19 what’s considered erratic? Idle is ~750. It goes up maybe to 900 then back to 750 every ~45sec

Code 19 - Engine off - No Vehicle Power (pins 37 + 57) or bad PCM VPWR

Revised 30 Mar 2019 to add computer wiring connector diagrams.

Key on, engine not running .
This is a wiring problem that is from a bad ECC power relay, bad connection, bad fuse link, bad ignition switch or a bad computer. The ECC relay is located on top of the computer under the passenger side kick panel. Pull the connector off any fuel injector and measure the voltage on the red wire: if its 12 volts or better, the ECC relay is OK. If the ECC relay is OK, pull the kick panel off and measure the voltage at computer pins 37 & 57. If it is 12 volts or more, then the computer's diagnostic firmware has taken a dump and is defective.

Computer wiring harness connector, wire side

Computer wiring harness connector, computer side

Key on, Engine running
Erratic idle during test (reset throttle & retest) - Idle Set Procedures .
See http://www.stangnet.com/mustang-forums/698148-help-me-create-surging-idle-checklist.html#post6855020 for the best way to set the mechanical base idle and cleaning procedure for the IAC/IAB.[/b][/b]

$wine · Dec 25, 2020

jrichker said:
Code 19 - Engine off - No Vehicle Power (pins 37 + 57) or bad PCM VPWR

Revised 30 Mar 2019 to add computer wiring connector diagrams.

Key on, engine not running .
This is a wiring problem that is from a bad ECC power relay, bad connection, bad fuse link, bad ignition switch or a bad computer. The ECC relay is located on top of the computer under the passenger side kick panel. Pull the connector off any fuel injector and measure the voltage on the red wire: if its 12 volts or better, the ECC relay is OK. If the ECC relay is OK, pull the kick panel off and measure the voltage at computer pins 37 & 57. If it is 12 volts or more, then the computer's diagnostic firmware has taken a dump and is defective.

Computer wiring harness connector, wire side

Computer wiring harness connector, computer side

Key on, Engine running
Erratic idle during test (reset throttle & retest) - Idle Set Procedures .
See http://www.stangnet.com/mustang-forums/698148-help-me-create-surging-idle-checklist.html#post6855020 for the best way to set the mechanical base idle and cleaning procedure for the IAC/IAB.[/b][/b]

Link is dead.

https://www.stangnet.com/mustang-forums/698148-help-me-create-surging-idle-checklist.html#post6855020

General karthief · Dec 25, 2020

Help me create the "Surging Idle Checklist"

Updated 26-Oct-2019 to clarify creeping idle RPM increase as the car is being driven. Many of you are familiar with the "Cranks OK, but No Start Checklist for Fuel Injected Mustangs" checklist and the No Crank Checklist. They are very effective in finding and eliminating the problems by use of...

forums.stangnet.com

Test
That one works,

JoeysAutos · Jan 8, 2021

Hey all, the day has finally come. It's time for me to put a cap on this thread, the issue is resolved! My no-hotstart issue was fixed with a new negative battery terminal.

Somebody on the Lincoln forums had me check the voltage at the red injector wire while cranking and I found that it was low and bouncing around 7.5volts. They guessed that this was too low for the injectors to pulse correctly and while I doubted this would prevent my noid light from flashing, I went along with it anyway. Since they were suspecting some sort of voltage drop issue they suggested that I hook up a running car to the battery and try to start it while the car was in no-start condition. I did so, whilst monitoring the red injector wire voltage. The car cranked for a while but the voltage on the red injector wire climbed and once it hit 8.5volts the car started. So the voltage drop suspicions were confirmed. At this point I began searching all over the computer's wiring for the source of this voltage drop but never really managed to find anything. On a whim I looked up the price of a new brass negative battery terminal and saw I could pick one up for $7 at AZ and figured, ah why not make sure the computer has a good ground. Snipped off the old terminal, stripped back the old wires and clamped them in the new terminal. Installed it, car started right up, got it hot, and wouldn't you know it. Car starts up every time now hot or cold.

Now, I want to thank everybody that contributed to this thread here because you helped keep me calm as I was pulling my hair out trying to find this issue. I might have given up completely if you all didn't have faith in me, and this car, so thank you all for that. Thank you General Karthief for trying your heart out to fix this junker from miles away sight unseen. I did end up putting a hair more advance into her because of you and she really appreciates it so thanks again man. Thank you jrichker for your amazing, detailed, and extremely helpful guides, they have been invaluable throughout this whole process. Thank you Stangnet community for helping me with a fricken Town Car that shouldn't have even been in your forums in the first place. I'm extremely grateful that forums like these exist and that helpful people from all over the place are willing to help random people they don't even know, they are an absolute godsend.

Happy New Year everybody! Cheers!

$wine · Jan 8, 2021

JoeysAutos said:
Hey all, the day has finally come. It's time for me to put a cap on this thread, the issue is resolved! My no-hotstart issue was fixed with a new negative battery terminal.

Somebody on the Lincoln forums had me check the voltage at the red injector wire while cranking and I found that it was low and bouncing around 7.5volts. They guessed that this was too low for the injectors to pulse correctly and while I doubted this would prevent my noid light from flashing, I went along with it anyway. Since they were suspecting some sort of voltage drop issue they suggested that I hook up a running car to the battery and try to start it while the car was in no-start condition. I did so, whilst monitoring the red injector wire voltage. The car cranked for a while but the voltage on the red injector wire climbed and once it hit 8.5volts the car started. So the voltage drop suspicions were confirmed. At this point I began searching all over the computer's wiring for the source of this voltage drop but never really managed to find anything. On a whim I looked up the price of a new brass negative battery terminal and saw I could pick one up for $7 at AZ and figured, ah why not make sure the computer has a good ground. Snipped off the old terminal, stripped back the old wires and clamped them in the new terminal. Installed it, car started right up, got it hot, and wouldn't you know it. Car starts up every time now hot or cold.

Now, I want to thank everybody that contributed to this thread here because you helped keep me calm as I was pulling my hair out trying to find this issue. I might have given up completely if you all didn't have faith in me, and this car, so thank you all for that. Thank you General Karthief for trying your heart out to fix this junker from miles away sight unseen. I did end up putting a hair more advance into her because of you and she really appreciates it so thanks again man. Thank you jrichker for your amazing, detailed, and extremely helpful guides, they have been invaluable throughout this whole process. Thank you Stangnet community for helping me with a fricken Town Car that shouldn't have even been in your forums in the first place. I'm extremely grateful that forums like these exist and that helpful people from all over the place are willing to help random people they don't even know, they are an absolute godsend.

Happy New Year everybody! Cheers!

Congrats. Something for me to look at also (neg batt term). Thanks for sharing.

General karthief · Jan 8, 2021

ANNNNNDðDDDD another happy customer

nickyb · Jan 8, 2021

It is what is all about.

$wine · Jan 14, 2021

JoeysAutos said:
Hey all, the day has finally come. It's time for me to put a cap on this thread, the issue is resolved! My no-hotstart issue was fixed with a new negative battery terminal.

Somebody on the Lincoln forums had me check the voltage at the red injector wire while cranking and I found that it was low and bouncing around 7.5volts. They guessed that this was too low for the injectors to pulse correctly and while I doubted this would prevent my noid light from flashing, I went along with it anyway. Since they were suspecting some sort of voltage drop issue they suggested that I hook up a running car to the battery and try to start it while the car was in no-start condition. I did so, whilst monitoring the red injector wire voltage. The car cranked for a while but the voltage on the red injector wire climbed and once it hit 8.5volts the car started. So the voltage drop suspicions were confirmed. At this point I began searching all over the computer's wiring for the source of this voltage drop but never really managed to find anything. On a whim I looked up the price of a new brass negative battery terminal and saw I could pick one up for $7 at AZ and figured, ah why not make sure the computer has a good ground. Snipped off the old terminal, stripped back the old wires and clamped them in the new terminal. Installed it, car started right up, got it hot, and wouldn't you know it. Car starts up every time now hot or cold.

Now, I want to thank everybody that contributed to this thread here because you helped keep me calm as I was pulling my hair out trying to find this issue. I might have given up completely if you all didn't have faith in me, and this car, so thank you all for that. Thank you General Karthief for trying your heart out to fix this junker from miles away sight unseen. I did end up putting a hair more advance into her because of you and she really appreciates it so thanks again man. Thank you jrichker for your amazing, detailed, and extremely helpful guides, they have been invaluable throughout this whole process. Thank you Stangnet community for helping me with a fricken Town Car that shouldn't have even been in your forums in the first place. I'm extremely grateful that forums like these exist and that helpful people from all over the place are willing to help random people they don't even know, they are an absolute godsend.

Happy New Year everybody! Cheers!

Chiming in again on this. Thanks for the tip. I replaced my negative battery terminal and noticed a slight improvement in my failure to restart when warm/hot. So I replaced my negative battery cable. . My ground cable from battery to block I was suspect of initially due to the brittle insulation and soaked with oil at the block. I had cleaned up the connection there but the cable itself was crustyand grimy. I dismissed this as contributing to my restart issue as the car started when cold. I am having consistent restart at operating temp without issue or hesitation. I am definitely relocating my tfi as I have had it temporarily relocated to a heat sync resting on top of the dizzy boot. TFI stayed cool there on the heat sync so definitely will be permanently relocated once I get the kit, never to return on the dizzy.

FE Build 1989 5.0 won't start when hot except when using starting fluid

jrichker

StangNet's favorite TOOL

$wine

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General karthief

wonder how much it would cost to ship you a pair

Help me create the "Surging Idle Checklist"

JoeysAutos

Member

$wine

Member

General karthief

wonder how much it would cost to ship you a pair

nickyb

I gotta say i never painted my nuts, Never Ever

$wine

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FE Build 1989 5.0 won't start when hot except when using starting fluid

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wonder how much it would cost to ship you a pair

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wonder how much it would cost to ship you a pair

I gotta say i never painted my nuts, Never Ever

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