Fuel Pressure Issue
Thread Starter
Burning Brakes
Joined: Sep 2004
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From: www.shockerracing.com
Fuel Pressure Issue
I have a 98 Corvette with a procharger and I had been running the Racetronix pump with a boost-a-pump and racetronix pump just went bad on me. I replaced it with the Bosch 040 pump and figured I should be able to run that pump without the BAP because it is supposed to flow so well. I disconnected the BAP and the fuel pressure sits at 60psi but when I get on it the pressure drops to around 40psi. This is the same problem I had with the Racetronix before adding the BAP. My car makes less than 600 hp so both of these pumps should have been able to handle keeping my pressure up right? Is there something else I need? Do I need to go to an adjustable fuel pressure regulator?
Tech Contributor
Joined: Jan 2007
Posts: 19,458
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From: Dyer, IN
I have a 98 Corvette with a procharger and I had been running the Racetronix pump with a boost-a-pump and racetronix pump just went bad on me. I replaced it with the Bosch 040 pump and figured I should be able to run that pump without the BAP because it is supposed to flow so well. I disconnected the BAP and the fuel pressure sits at 60psi but when I get on it the pressure drops to around 40psi. This is the same problem I had with the Racetronix before adding the BAP. My car makes less than 600 hp so both of these pumps should have been able to handle keeping my pressure up right? Is there something else I need? Do I need to go to an adjustable fuel pressure regulator?
Thread Starter
Burning Brakes
Joined: Sep 2004
Posts: 812
Likes: 20
From: www.shockerracing.com
What is a direct wire harness from the alternator? I am not sure if it does or not, the car already had the Racetronix in it when I bought it. I have not tested the regulator at the rail, but I had put a new one in about a year ago.
Last edited by ShockerRacing; Sep 19, 2011 at 05:42 PM.
Tech Contributor
Joined: Jan 2007
Posts: 19,458
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From: Dyer, IN
Drifting
Joined: May 2010
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From: Pearland, TX
Look at the right side of the alternator. There is a big red wire hooked into a black fuse-holder that is mounted to the frame. That wire runs back to the alternator. It uses the heavier 10ga wire to power the fule pump instead of the smaller factory wire.
Last edited by Lothar34; Sep 19, 2011 at 05:53 PM.
Instructor
Joined: Apr 2006
Posts: 128
Likes: 0
From: Washington IL
I have an auto meter and it was way off
simple process to check it at a shop or yourself
auto meter has excellent service and will get it back to you quickly
they replaced mine for free
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Pro
Joined: Feb 2006
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From: Jacksonville , NC
Racetronix makes a wire kit for the C5. http://www.racetronix.com/RX-C5A-FPWH-2.html from their Website.
I agree 60 to 40 is quite a drop. Have seen a suspect alternator cause this kind of drop also. Check the voltage directly from the alt.
I agree 60 to 40 is quite a drop. Have seen a suspect alternator cause this kind of drop also. Check the voltage directly from the alt.
Thread Starter
Burning Brakes
Joined: Sep 2004
Posts: 812
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From: www.shockerracing.com
Racetronix makes a wire kit for the C5. http://www.racetronix.com/RX-C5A-FPWH-2.html from their Website.
I agree 60 to 40 is quite a drop. Have seen a suspect alternator cause this kind of drop also. Check the voltage directly from the alt.
I agree 60 to 40 is quite a drop. Have seen a suspect alternator cause this kind of drop also. Check the voltage directly from the alt.
Supporting Vendor
Joined: Dec 2001
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From: A dealer near you.
Make sure you use a Littelfuse or Bussman brand fuse only. Off-shore fuses will melt/fail and damage your harness.
Thread Starter
Burning Brakes
Joined: Sep 2004
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From: www.shockerracing.com
Thanks for the info! I am trying to not run the BAP, should I still upgrade the fuse? Also, if that fuse was blown does that make sense that my fuel pressure would be dropping?
Tech Contributor
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From: Dyer, IN
Supporting Vendor
Joined: Dec 2001
Posts: 1,573
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From: A dealer near you.
Yes you should upgrade the fuse with the BAP. Try 25 amps (GOOD BRAND ONLY). If your pump does not get the proper voltage then your pressure will drop. A Walbro pump will go from apx. 220LPH to 300LPH @ 58PSI when bumped from 13.5V to 16.0V.
Thread Starter
Burning Brakes
Joined: Sep 2004
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From: www.shockerracing.com
Fuel pressure is still dropping with the BAP disconnected but I really don't want to have to hook the BAP back up because I am afraid it prematurely burned out my Racetronix pump.
Supporting Vendor
Joined: Dec 2001
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From: A dealer near you.
Why would it cause premature failure unless you were running it at 16 volts + all the time. The BAP should only boost the voltage when needed / under high engine load.