# VR6 fuel pump upgrading?



## GTTechnics (Apr 2, 2003)

Recently I purchased a mk3 SC vr6 that supposedly has a Walbro inline fuel pump with the stock in tank fuel pump. When I bought the car the guy warned me that I should refill the tank at 1/4 or run the risk of having it "hiccup", which he blamed on the fuel pickup. Low and behold later I noticed when I took a hard turn and powered out of it the car would buck and/or lose power (which obviously seems like a fuel issue). I was about to just replace the intank fuel pump assembly, but I seem to remember people talking about mk2's or mk4's having a better in tank assembly due to a reservoir type setup. Does anyone know anthing of this? Are there any better aftermarket solutions for intank replacement? Am I looking to fix the wrong component of the system?


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## MunKyBoy (Sep 16, 2002)

*Re: VR6 fuel pump upgrading? (GTTechnics)*

People have that problem when they install aftermarket in-tank fuel pumps into MK3's.. $20 says the dude you bought it from put in an in-tank fuel pump that wasn't OEM.. If you have a OEM pump the pick up should be fine, but i've heard that with aftermarket models they don't have mounts to be able to mount it correctly to pick up the last 1/4 or so of fuel in the tank.. I would just replace the fuel pump and take a look and see if there really is a inline pump.. I'm willing to bet that there isn't.


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## GTTechnics (Apr 2, 2003)

*Re: VR6 fuel pump upgrading? (MunKyBoy)*


_Quote, originally posted by *MunKyBoy* »_People have that problem when they install aftermarket in-tank fuel pumps into MK3's.. $20 says the dude you bought it from put in an in-tank fuel pump that wasn't OEM.. If you have a OEM pump the pick up should be fine, but i've heard that with aftermarket models they don't have mounts to be able to mount it correctly to pick up the last 1/4 or so of fuel in the tank.. I would just replace the fuel pump and take a look and see if there really is a inline pump.. I'm willing to bet that there isn't.









well, looking at the STACK of reciepts that came with the car, I have found reciepts for a T-Rex vortech inline, and some labor for "install intank fuel pump, modify to fit"...it sounds like this is all beginning to add up. So is there something I can replace in tank that will pick up properly and be able to feed the T-rex?


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## MunKyBoy (Sep 16, 2002)

*Re: VR6 fuel pump upgrading? (GTTechnics)*

I would just go with stock. For one, nothing other than factory has been able to pick up the last couple gallons of gas, and two, you don't really need a beefy intank AND inline fuel pump.. A stock in-tank and an aftermarket inline can yeild ~450whp no problem. I'm running stock intank and a walbro inline and I haven't had any problems with fuel delivery. Im probably around 300-350whp and my only limiting factor now is running out of injector..


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## Jefnes3 (Aug 17, 2001)

*Re: VR6 fuel pump upgrading? (GTTechnics)*

Been said before...
Install or KEEP the stock pump and module.
If you need ~more pump install it in-line, or suffer BAD low fuel
driveability....

Most likely you'll need an ENTIRE stock pump and module,
as your current module has been cut-up to fit the T-Rex pump.
-Jeff


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## GTTechnics (Apr 2, 2003)

*Re: VR6 fuel pump upgrading? (Jefnes3)*


_Quote, originally posted by *Jefnes3* »_Been said before...
Install or KEEP the stock pump and module.
If you need ~more pump install it in-line, or suffer BAD low fuel
driveability....

Most likely you'll need an ENTIRE stock pump and module,
as your current module has been cut-up to fit the T-Rex pump.
-Jeff

the T-rex is an inline, so I am guessing that there is on intank and one inline (unless there is a way to mount an inline in the tank that I am not aware of?). IF this is the case, will the stock pump be able to feed the inline? or does it work differently than I am thinking?


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## Scott F. Williams (Oct 14, 2000)

*Re: VR6 fuel pump upgrading? (GTTechnics)*


_Quote, originally posted by *GTTechnics* »_
the T-rex is an inline, so I am guessing that there is on intank and one inline (unless there is a way to mount an inline in the tank that I am not aware of?). IF this is the case, will the stock pump be able to feed the inline? or does it work differently than I am thinking?

You can't drop an inline pump into the gas tank. The stock intank is perfectly capable of feeding a strong inline. That's the set up to use. Go for it without any fear.


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## vr6ofpain (Feb 5, 2004)

*Re: VR6 fuel pump upgrading? (GTTechnics)*


_Quote, originally posted by *GTTechnics* »_Recently I purchased a mk3 SC vr6 that supposedly has a Walbro inline fuel pump with the stock in tank fuel pump. When I bought the car the guy warned me that I should refill the tank at 1/4 or run the risk of having it "hiccup", which he blamed on the fuel pickup. Low and behold later I noticed when I took a hard turn and powered out of it the car would buck and/or lose power (which obviously seems like a fuel issue). I was about to just replace the intank fuel pump assembly, but I seem to remember people talking about mk2's or mk4's having a better in tank assembly due to a reservoir type setup. Does anyone know anthing of this? Are there any better aftermarket solutions for intank replacement? Am I looking to fix the wrong component of the system?

what type of SC kit you running....specifically what software? AMS, ATP, VF, C2...or is it standalone?


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## GTTechnics (Apr 2, 2003)

*Re: VR6 fuel pump upgrading? (vr6ofpain)*


_Quote, originally posted by *vr6ofpain* »_what type of SC kit you running....specifically what software? AMS, ATP, VF, C2...or is it standalone?

eurotech...but I am planning to go c2 15psi in the near future.


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## vr6ofpain (Feb 5, 2004)

*Re: VR6 fuel pump upgrading? (GTTechnics)*


_Quote, originally posted by *GTTechnics* »_eurotech...but I am planning to go c2 15psi in the near future.

Their kit was similar to the AMS in that it ran the factory 19# injectors at high pressures (a la EIP style), correct? That is interesting that it has an inline and/or tank pump upgrade. I wonder if their kit worked more than the AMS one did (though both are obviously problematic and outdated compared to C2 and even VF).
Have you dyno'd the car?


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## GTTechnics (Apr 2, 2003)

*Re: VR6 fuel pump upgrading? (vr6ofpain)*


_Quote, originally posted by *vr6ofpain* »_
Have you dyno'd the car?

yeah, 264 at the wheels with a 3.17" pulley (10psi)...


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## vr6ofpain (Feb 5, 2004)

*Re: VR6 fuel pump upgrading? (GTTechnics)*


_Quote, originally posted by *GTTechnics* »_yeah, 264 at the wheels with a 3.17" pulley (10psi)...

ya I have an AMS kit with the 3.17" pulley and the 'single idler'...I currently am running C2's stage I software (with their CAI and upper intake tubes) and ACCEL 310cc injectors. My car is having some issues, but them seem to be more related to something with my own motor (no one else has the same issues). I'm gonna try to dyno it sometime soon, just to see where the car is, fuel and power wise.
no fuel pump mods and it runs on the original 3.0bar FPR.


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