Forced Induction Hi Flow Fuel Pump W/o Supercharger

kcpope

New Member
Mar 11, 2008
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California
What's up guys. I have the opportunity to purchase an 01 Bullitt that comes with a vortech V2 that has yet to be installed. The owner has however, already installed a high flow fuel pump in preparation for the vortech install.

Here's my question. It's gunna take me a couple months before I get around to installing the vortech. Will it harm the car at all to be running around with the high flow fuel pump w/o the supercharger installed yet? Any adverse affects?

Thanks in advance.
 
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Note. There is a table inside the PCM that defines what FPDM duty cycle will produce a certain rate of flow. It has a limited number of "steps". That is to say the duty cycle of the FPDM is not infinitely variable.

Let's take the case of a "stupidly" large fuel pump. Let's also say that the PCM pump table is NOT matched to the capability of said fuel pump. There is a limit to the amount of control that the PCM has over the Fuel pump driver module. Control is done in "steps". It's possible that the minimum step that the PCM has in the table results in soooooo much fuel delivery that an over pressurization event will occur. The PCM will respond by shutting off the fuel pressure.

This creates a situation where the fuel pressure "spikes" and then plunges over and over again. (wash, rinse, repeat).

Bottom line. Within "reason" a larger fuel pump will work with a stock PCM tune. Exactly where that line is I can't say. But should you encounter poor running or ruptured FRPS it may be related to this problem.
 
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Thanks for the info guys. Very good to know.

I just picked up the car today. Overall I'm very happy with what I see so far.
  • It came with a new vortech V2 kit that has yet to be installed. The only part the previous owner got around to installing was the fuel pump. (hence my original question)
  • The car starts and idles just fine. But as I drove it around the neighborhood there is slight hesitation/bogging when getting into the throttle.
  • I plan on dropping the tank and putting the stock fuel pump back in.
  • Anyone have any idea what type of fuel pump would have come with a vortech v2 system bought about 2 years ago? Doesn't really matter, cuz I'm going back to stock anyway, but it would be nice to have some confidence that this is indeed the problem.
for what it's worth, here she is:

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