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Fuel pressure regulater

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Old Dec 9, 2012 | 07:56 PM
  #1  
Claybraham's Avatar
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From: Nc
Car: 91 rs camaro hard top
Engine: 350 vortec
Transmission: 5 speed. T5
Axle/Gears: 3.70 gear 9 bolt posi. disc brakes
Fuel pressure regulater

Po has put in a Holley pressure regulater. It is carbureted, but was tbi. They have the return line capped of on the regulater and the return line it self going back to the tank is capped. Is that ok? Should I put in a return line, or could I just put on a fuel pressure gauge? What would you recommend? Thanks!
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Old Dec 9, 2012 | 09:14 PM
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Re: Fuel pressure regulater

Sounds pretty much a disaster...

The fuel pumps in EFI systems are constant-volume; they ALWAYS move the same amount of fuel every time they rotate (or at least try to), out of which the engine consumes some portion that varies according to load and RPMs; and are designed expecting that any "unused" fuel will be returned to the tank. THat's how the regulator in the EFI system works, is to "leak" enough fuel into the return to lower the pressure to the desired level.

With your dead-heading system, your pump is straining to the absolute max and then some, at all times. Not a recipe for a long and happy life.

I'd recommend hooking the return line back up.
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Old Dec 9, 2012 | 09:30 PM
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From: Nc
Car: 91 rs camaro hard top
Engine: 350 vortec
Transmission: 5 speed. T5
Axle/Gears: 3.70 gear 9 bolt posi. disc brakes
Re: Fuel pressure regulater

Yeah I no... The fuel pump is wired to a toggle, also ignition is wired to a push start. I think that vats has the car shut down and po bypassed it by doing that. It's a mess... If I don't put the return line in what's the effect of it? Car runs great but it just hasn't been done right :/ I know with the toggle my fuel pump is running constant and that's not good
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Old Dec 10, 2012 | 04:06 PM
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
The in-tank electric pump will overheat and die prematurely.
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Old Dec 11, 2012 | 02:12 PM
  #5  
Claybraham's Avatar
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From: Nc
Car: 91 rs camaro hard top
Engine: 350 vortec
Transmission: 5 speed. T5
Axle/Gears: 3.70 gear 9 bolt posi. disc brakes
Re: Fuel pressure regulater

Also what should my fuel pressure be? It's carbureted witha Quadrajet, it's set at 4.5 right now. Just want to make sure if that's good. Thanks
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Old Dec 11, 2012 | 07:32 PM
  #6  
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
4.5 should be fine.
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Old Dec 14, 2012 | 07:49 AM
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Car: 1984 Trans Am
Engine: LS1383 in work
Transmission: Magnum F - to be installed
Axle/Gears: Zexel Torsen 3.73, 28-spline mosers
Re: Fuel pressure regulater

Less than 4 and you'll see the engine start to stall out under hard accelleratrion and cornering as it can't keep the bowl full. Over 6 and it'll start pushing fuel out of every orafice in the carb.

I'd go pull a column and under dash harness from a donar car and fix that mess the previous owner made. That would drive me nuts.
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Old Dec 14, 2012 | 02:33 PM
  #8  
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From: Nc
Car: 91 rs camaro hard top
Engine: 350 vortec
Transmission: 5 speed. T5
Axle/Gears: 3.70 gear 9 bolt posi. disc brakes
Re: Fuel pressure regulater

Yeah it's about to drive me crazy! Po has just done so much wiring damage it's crazy! Turn signals or gauges don't work either :/
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