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Does'nt sound normal. I did the mod a couple weeks back and the only thing that changed is my gas milage got worse. Maybe someone else can shed some light.
 

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The 12v mods is not needed unless your using the FFCD. If you are using a Greddy BCC, you should not do the 12 volt mod.

Later, Steve
 

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Steve Jarvis said:
The 12v mods is not needed unless your using the FFCD. If you are using a Greddy BCC, you should not do the 12 volt mod.

Later, Steve
Amen. The 12v mod can also cause other problems like going lean after the car has been on for a while as the fuel pump can overheat running 12v for extended periods.

As for the noise, that's normal... stock, the fuel pump doesn't even turn on AT ALL until you start the car... so when you do the 12v mod you will hear the pump.

I undid the 12v mod on my car.

Andi
 
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Andi said:
Amen. The 12v mod can also cause other problems like going lean after the car has been on for a while as the fuel pump can overheat running 12v for extended periods.
Do you know this for sure? Never heard of this, as 99% of in-tank fuel pumps on any given car run 12V (actually 14.4V) all the time. It sits submerged in gasoline, I don't see how it can overheat unless you were real low on gas.

LowerJerZey: Yes it will be louder. Stock it doesn't run until the engine starts. Now you actually hear it run. Do you notice it when the car is running? You shouldn't, so it's no big deal.

Now a external pump, THOSE are noisy.
 

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AnArKey said:


Do you know this for sure? Never heard of this, as 99% of in-tank fuel pumps on any given car run 12V (actually 14.4V) all the time. It sits submerged in gasoline, I don't see how it can overheat unless you were real low on gas.

LowerJerZey: Yes it will be louder. Stock it doesn't run until the engine starts. Now you actually hear it run. Do you notice it when the car is running? You shouldn't, so it's no big deal.

Now a external pump, THOSE are noisy.
I experienced this problem myself... going lean at WOT during long trips....

Andi
 

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It sounds like I need to undo mine. I will do this today. Does anybody know if this will change gas milage at all?

Jeff
 

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I didn't notice a difference with mine.

Later, Steve
 

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Discussion Starter #9
Steve Jarvis said:
The 12v mods is not needed unless your using the FFCD. If you are using a Greddy BCC, you should not do the 12 volt mod.

Later, Steve
I did the mod because I plan to be BPU++++ by spring. I was taking out my spare the other day so I just did the 12v mod to get it out of the way. Just to be safe I'm gonna undo it. But, should I redo it once I'm BPU++++ or is it unnecessary. I am running the Greddy BCC.
 

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LowerJerZey said:


I did the mod because I plan to be BPU++++ by spring. I was taking out my spare the other day so I just did the 12v mod to get it out of the way. Just to be safe I'm gonna undo it. But, should I redo it once I'm BPU++++ or is it unnecessary. I am running the Greddy BCC.
It's unnecessary. The only time you would need to do this mod is if you do the FFCD which is in itself not recommended.

Andi
 

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Your pump should not get hot from running 12V all the time.

Alot of other cars use supra pumps (denso) as upgrade pumps which run the pump at 12V all the time and do not experience problems.

I have a friend that runs a Kenne-Bell boost-a-pump at like 15 volts and has never had a problem. (it is boost activated, however..) but his pump is hotwired (as almost all buicks are hotwired as well) and runs 14V 24x7 (and this is on a stock supra pump)
 
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I've heard that its not the pump that overheats (or heats up), it's the actual wires. Wires get warm/hot to the touch after doing the 12v mod. Most likely this is due to the small wire gauge/diameter.

I have dual in-tank stock pumps, with upgraded wiring (10-gauge) and an in-line 30A latching relay.
 

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Andi, if I remember Bryce disagreed with you on the fuel pump overheating thing. I've also seen 16V to the pump on one car with a GReddy A/F gauge and he says hes never had a problem.

Its great if you want to do 12v, TTC and EGR, saves $100 for the BCC.
 

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Grant said:
Andi, if I remember Bryce disagreed with you on the fuel pump overheating thing. I've also seen 16V to the pump on one car with a GReddy A/F gauge and he says hes never had a problem.

Its great if you want to do 12v, TTC and EGR, saves $100 for the BCC.
Bryce disagreed, Jarrett agreed. Jarrett in fact is the person who told me to undo the 12v mod for this reason.

I'd rather be safe and spend the $100....

btw you forgot the FFCD in your list. Heh. =)

Andi
 
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