How to verify both GT500 pumps are working?

[dmhines]

I installed a FRPP GT500 pump setup a few weeks back. I was driving into work this morning wondering if both pumps were actually working. Outside of datalogging how would you verify? I figured if I pulled the factory fuel pump fuse from under the hood ... then the second pump should continue to run ... therefore the car should continue to run. Think that would be a good way to verify? Anyone ever try it?

 

[JeremyH]

Unplug one fdpm at a time and key-on to prime and you will hear each pump come on.

 

[05yellowgt]

Unplug one fdpm at a time and key-on to prime and you will hear each pump come on.

+1 this is the best way to test.

 

[dmhines]

Thanks guys ... I'll do that tonight ...

 

[JeremyH]

 

[Skarkull]

I figured if I pulled the factory fuel pump fuse from under the hood ... then the second pump should continue to run ... therefore the car should continue to run. Think that would be a good way to verify? Anyone ever try it?

If I looked at the wiring correctly, you are now using the original wiring that turned on the factory pump to activate the relay. If you pull your original factory pump fuse, you'll have no power to turn on the relay. Therefore, no fuel at all.

 

[dmhines]

If I looked at the wiring correctly, you are now using the original wiring that turned on the factory pump to activate the relay. If you pull your original factory pump fuse, you'll have no power to turn on the relay. Therefore, no fuel at all.

Thanks ... yes that makes sense. Glad I didn't try my method ... I would have been scratching my head when the car wouldn't start!

 

[07VistaChicago]

Unplug one fdpm at a time and key-on to prime and you will hear each pump come on.

Yep, this is the way I verified mine.

What is the issue you are looking for? Just verification or other issues? I was originally chasing down a lean issue. Turned out to be the tune and the way the tuner set up the pumps (didn't tell the car it had two).

 

[dmhines]

Yep, this is the way I verified mine.

What is the issue you are looking for? Just verification or other issues? I was originally chasing down a lean issue. Turned out to be the tune and the way the tuner set up the pumps (didn't tell the car it had two).

Just want to verify I installed correctly ...

Also .. I have asked Jim Jr. at JDM if he needed to update my tune for Dual Pumps. He said there is nothing for him to update in the tune for dual pumps .. they just work.

 

[JeremyH]

Just want to verify I installed correctly ...

Also .. I have asked Jim Jr. at JDM if he needed to update my tune for Dual Pumps. He said there is nothing for him to update in the tune for dual pumps .. they just work.

I have seen you post in the other thread about this and what JDM said but I have seen too many people with issues after swapping in a gt500 setup with no retune. And after the tune was adjusted they were good to go.

 

[Kuro!]

It's called an FPR "brah".

Wouldn't the PCM adjust fuel trim and duty cycle based upon the FPR's reading?

 

[JeremyH]

Called a FPR brah.

Wouldn't the PCM adjust fuel trim and duty cycle based upon the FPR's reading?

We dont have a FPR on our cars.

 

[Kuro!]

What sits on top of the driver side rail.

EDIT: What your saying is that there is no way for the PCM to adjust fuel trims?

 

[JeremyH]

What sits on top of the driver side rail.

Fuel rail pressure sensor.

It just reads delta pressure and sends it to the pcm then the pcm uses the fpdm to control pump speed and maintain delta pressure.

A fuel pressure regulator sits at the fuel rail and maintains a certain pressure regardless of pump speed. Most often used on return setups.

 

[Kuro!]

So the PCM just regulates voltage to the FPDM based upon the delta pressure read at the rail?

I know what a "stand alone" adjustable FPR, this is interesting... thanks for the knowledge.

 

[JeremyH]

So the PCM just regulates voltage to the FPDM based upon the delta pressure read at the rail?

I know what a "stand alone" adjustable FPR, this is interesting... thanks for the knowledge.

Sorta, the fpdm is what actually regulates voltage to the pump according to the pressure signal from the pcm.

Thats why you wire a bap pre-fpdm in our cars, that way the fpdm always has 17volt dc input and then will regulate that voltage to the pumps based on load/demand.


And the v6 doesnt even have the fuel rail pressure sensor so i know when guys do v8 swaps you have to run a vac line to the sensor for it operate properly as the frps needs to know vac/pressure in the manifold in order to send the correct fuel pressure signal to the pcm.

 

[Kuro!]

Ah, makes sense. Thanks

I did Bmaxwell's set up for him, couldn't using shitty wire on the relay potentially fuck with the voltage and make the pumps act weird?

 

[JeremyH]

Cool, yeah i gave him alot of pointers for his setup and sold him the dual pump hat he has. Yeah you want nice wire with solid connections to ensure the best signal and have less amperage drop.

 

[dmhines]

I have seen you post in the other thread about this and what JDM said but I have seen too many people with issues after swapping in a gt500 setup with no retune. And after the tune was adjusted they were good to go.

I know ... I even verified with him again and he says there is nothing to tune.

 

[Kuro!]

Cool, yeah i gave him alot of pointers for his setup and sold him the dual pump hat he has. Yeah you want nice wire with solid connections to ensure the best signal and have less amperage drop.

lol I know, you went above and beyond on helping.