fuel pump runs, engine is off, help!
#1
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fuel pump runs, engine is off, help!
Have a 1990 toyota extended cab pick up, 3.0 v6. As soon as I stick the key in the ignition, I can hear the fuel pump wine. I read a couple posts, disconnected the AFM, and the pump still ran as soon as I turn the key, and it keeps running. ...
If it's not the afm, where do I start??
If it's not the afm, where do I start??
#2
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Are you sure your key is actually off? I know in my truck, i can pull the key out before its actually in the off position. You can check easily by seeing if your radio or clock actually turns off. If your clock stays lit up with your key out, you need to depress the little button on top of your steering column, while turning your key backwards one more click. That should fully turn off the remaining power, which could be why your pump is running!
If its not that, I am not sure everyone who drives my truck never shuts it off all the way and I run into this alot.
If its not that, I am not sure everyone who drives my truck never shuts it off all the way and I run into this alot.
#4
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As far as I know the vehicle is stock. And I also know the fuel pump is not supposed to run in the acc position, only w hen the vehicle is running, yet as soon as I shut of the engine I can still hear it wine, and yes...when I disconnected the afm wire and I still hear it, it may be haunted, but for real, would a bad fuel pump relay cause this?
#5
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There is no fuel pump relay, but there is a Circuit Opening Relay which is sorta the same. The circuit opening relay has two windings, one powered by the VAF when the engine is sucking air, the other powered by the key in the STArt position (not accessory, not ON, not with just the key in the keyway). When the COR closes it powers the fuel pump.
Do be sure the whine (wine?) you hear is the fuel pump; it pulls enough power to run the battery down in a few hours. Next, access the COR http://web.archive.org/web/201003261...96circuito.pdf and confirm that it is "clicking" (it's quiet; you might need a homemade stethoscope) when you turn the key to acc. If not, either have a bad (stuck closed) COR, or you have a short to 12v toward the pump. Then disconnect the COR and check for voltage on the STA pin. If you have voltage there with the key in acc you have a bad starter (key) switch.
Do be sure the whine (wine?) you hear is the fuel pump; it pulls enough power to run the battery down in a few hours. Next, access the COR http://web.archive.org/web/201003261...96circuito.pdf and confirm that it is "clicking" (it's quiet; you might need a homemade stethoscope) when you turn the key to acc. If not, either have a bad (stuck closed) COR, or you have a short to 12v toward the pump. Then disconnect the COR and check for voltage on the STA pin. If you have voltage there with the key in acc you have a bad starter (key) switch.
#7
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Thread Starter
There is no fuel pump relay, but there is a Circuit Opening Relay which is sorta the same. The circuit opening relay has two windings, one powered by the VAF when the engine is sucking air, the other powered by the key in the STArt position (not accessory, not ON, not with just the key in the keyway). When the COR closes it powers the fuel pump.
Do be sure the whine (wine?) you hear is the fuel pump; it pulls enough power to run the battery down in a few hours. Next, access the COR http://web.archive.org/web/201003261...96circuito.pdf and confirm that it is "clicking" (it's quiet; you might need a homemade stethoscope) when you turn the key to acc. If not, either have a bad (stuck closed) COR, or you have a short to 12v toward the pump. Then disconnect the COR and check for voltage on the STA pin. If you have voltage there with the key in acc you have a bad starter (key) switch.
Do be sure the whine (wine?) you hear is the fuel pump; it pulls enough power to run the battery down in a few hours. Next, access the COR http://web.archive.org/web/201003261...96circuito.pdf and confirm that it is "clicking" (it's quiet; you might need a homemade stethoscope) when you turn the key to acc. If not, either have a bad (stuck closed) COR, or you have a short to 12v toward the pump. Then disconnect the COR and check for voltage on the STA pin. If you have voltage there with the key in acc you have a bad starter (key) switch.
Thanks Scope, I always look forward to your replys, Ill check out the link and test the COR.
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#8
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So ...
Looks like the fuel pump has been tampered with by a previous owner. As there is a wire spliced in and running along frame directly to fuel pump, I will take the dash apart tomorrow and see where the wire is ran to. Just to confirm, the C ircut Open Relay is on the passenger side under glove box correct? Or is it the relay under driver side above brake pedal?
Looks like the fuel pump has been tampered with by a previous owner. As there is a wire spliced in and running along frame directly to fuel pump, I will take the dash apart tomorrow and see where the wire is ran to. Just to confirm, the C ircut Open Relay is on the passenger side under glove box correct? Or is it the relay under driver side above brake pedal?
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Sean Mccarrall
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08-11-2016 10:56 AM