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Will I need to get tuned if I install the fuel pump only? I havent bought bigger injectors yet, but I have the fuel pump and was thinking about putting it in, but someone told me that it would make the car run really rich. :confused: Can anyone help me out with this?

Thanks

Mark
 

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I wish people would stop spreading mis-information about this. Whoever told you this is dead wrong. The role of the fuel pump is to do nothing but send fuel from the tank to the fuel rail. Thats it. The pressure regulator controls the pressure in the rail. The rail is basically a reservoir for the injectors to draw fuel from and the injectors use what they require and the remaining fuel is returned via the return line back to the tank. The benefit of a larger pump is when the engine requires more fuel than the pump can supply(high RPM, WOT, high boost, etc.). At that point the pressure regulator is still trying to maintain pressure in the rail. The pump cannot flow enough fuel at that pressure at the required flow rate to feed the injectors. A higher flow pump cures this under certain circumstances. The result of using a larger pump is the fuel making more trips through the rail. It can also result in more stable fuel pressure due to higher flow limit.

So in answer to your question. No. A tune is not required and you will not run rich. Sorry for the rant. It's not directed toward you at all. Just trying to make sure the proper info is out there. Hope it helps.:D

T
 

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^^^Thats what I was trying to say. No one gagged me fast enough.:D
 

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:tup: :D Been messing with fuel injection for 15 years now so it's pretty intuitive for me now but don't ever ask me to tune a carb if you want it to run right(well except for an RC plane engine).:lol:
 

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I may be wrong, but I was under the assumption every car built after I think 2002 had to be returnless fueling for emmissions.
 

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I know when I changed the fuel pump in my 06 it had a smaller high pressure supply line from the pump and a larger low pressure return line going back into the tank. If it was returnless there would only be a single high pressure line from the pump. The emissions aspect is handled by fully sealing gas caps and charcoal canisters. On the wifey's Jetta if you leave the gas cap loose or off the CEL comes on.
 

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anthongy817 said:
How do most people get to the shop to get tuned if they were to install the injectors themself? I'm sure you can flatbed it there...but i don't see many people doing that..
They get their tuner to send them a rough map that will have a rough guestimate on the injector scalar and latency values. This, in theory, allows the car to get to the shop. The person is advised not to go into boost at all and drive it like a grandma.

NEVER attempt to drive a car with larger injectors and/or a big maf on a tune written for stock injectors and a stock-type 65mm intake.

t
 
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