trying to figure out my itb parts

I'm doing my fuel system the same way. I'm using a surge tank I got in the UK.
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pressure in the surge tank will be only 2-3psi. there is an unregulated (freeflow) return/overflow line from the surge tank to the fuel tank.

I don't think it will be a problem.


JoBy has done his own version of the surge tank (with 2 hi-pressure pumps)... maybe he can tell us if it was a problem.
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But the 2 psi will be added to what you set the fuel pressure at, there's just no free lunch there. If you return straight to the tank you will not have that issue (and it has to be returned above the fluid level, otherwise the fluid column weight at the return port will also affect -raise- the actual FP). The reading off the fuel pressure gauge will still be accurate as you are monitoring actual fuel rail pressure but since the additional pressure increase due to the surge tank may not be constant you may have a fluctuation in system pressure, potentially leading to fuel metering issues and funky symptoms. Steady and predictable fuel pressure is key to a finely tunes EFI setup.
 
(and it has to be returned above the fluid level, otherwise the fluid column weight at the return port will also affect -raise- the actual FP)
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with the stock 82 fuel sender, the return line (5/16in.) is below fuel level, almost to the bottom of the tank (near pump).

The reading off the fuel pressure gauge will still be accurate as you are monitoring actual fuel rail pressure but since the additional pressure increase due to the surge tank may not be constant you may have a fluctuation in system pressure
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I'm using an EBL modified truck ecm. you can plug up to 8 analog sensors. I plan to monitor fuel pressure (only need the autometer sender) so I should be able to see this fluctuation.
 
Vince'82 said:
with the stock 82 fuel sender, the return line (5/16in.) is below fuel level, almost to the bottom of the tank (near pump).
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Yes, but it comes in from the top.
Vince'82 said:
I'm using an EBL modified truck ecm. you can plug up to 8 analog sensors. I plan to monitor fuel pressure (only need the autometer sender) so I should be able to see this fluctuation.
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1227747?
 
1227747?
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yes. it started its life as a 7747. but it's now and "EBL Classic" ECM (ROM less, lockers board and custom code). more details here :
http://www.dynamicefi.com/EBL_Classic.php



Personally with an open end (return to the tank I don't see how pressure could even be building up in there.
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I don't think it will be worse than using an 85+ fuel pump in a stock 82 crossfire with the little 5/16" return line. and no one complains about this mod :D

if we have pressure in the return line, it's time to upgrade to a bigger one.
I upgraded my return line to 3/8".
 
I have read that if you use a 1997 up corvette fuel filter you no longer have to run the return line from the front of the car. All you would have is a return from the filter, which you can place in the rear of the car, to the tank. The set up I am thinking about using is the generic pump Gene spoke about feeding the 1997 filter with return and only having to plumb one supply line to the engine. For this set up, I believe you just block the return line at the fuel injection unit.
 
I just tried to find my source for this comment. I think this system may only apply to the LS engine swaps. A fuel injection system with now return line could possibly work with one of the pressure regulators similar to the one race pumps sells?

Does anyone know if you could run the 1997 corvette filter with a tpi and just block the return?
 
Jupiter60 said:
Does anyone know if you could run the 1997 corvette filter with a tpi and just block the return?
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it won't work with a TPI.

you need a VAFRP (vacuum assisted fuel pressure regulator) so the absolute fuel pressure follows engine load (this way, relative fuel pressure is constant at the injector tip).

in a LSx engine, fuel pressure doesn't move with engine load and the difference is computed by the PCM.
 
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