I need to replace the fuel pump on my 99 TA which already had an LS3 swapped in it. My understanding is that the 4th gens have a different style fuel system than what could support an LS3 swap. My question is, does anyone know what part I should replace with? There is return and returnless along with many different flow rates. Making about 440hp wheel through a 4L60.

 

I have an LS3 02 T/A with a Racetronix 255 and the hot wirekit.

http://www.ws6project.com/user_stor/...x-fuel-system/

 

Have you already pulled the fuel pump? If not could you take a pic of the filter that is installed on the car? It would help to see that, as it might tip us off if some installed a vette style fuel pump in the tank.

 

Well, I manned up and just cut the trap door. Looks stock, though.

 

Im putting down 430 with an LS1 and running the stock pump, been to the track an wrung her out, no issues, if your gonna push the LS3 more, than maybe a racetronix setup is what you might want to try.

 

I'm currently evaluating my options because my current fuel pump is going out. Almost left me stranded yesterday.

 

Can anyone confirm in the pictures above that this is a valid fuel system setup? As far as I can tell in one of the pictures, the return line is just open to atmosphere (at least I think that is what I'm looking at). So, I have a stock fuel pump in line with a fuel filter and a pressure regulator directly plumbed to the fuel rails without any sort of return. This to me doesn't seem right... How does the fuel pump know to shut off without pressure feedback to the ecu? (Or is this built into the pump?)

Does the fact that I have an LS3 in a 4th gen change anything here?

I feel like I could probably just order the racetronix pump and kit and I would be okay, but I want to verify the setup I have currently is correct and at least learn something in the process.

 

Have you determined if the previous owner had already installed a hot wire kit and/or aftermarket pump in the car or not?

Just speculation, but seems unusual that the previous owner would convert the fuel supply to a return style system, add rails, install an FPR with gauge and not upgrade the pump and stock wiring. I think the first thing to do is pull the fuel module and see what's inside.

Why? You need to determine what pump is in the fuel sender module. Has the intank regulator been removed, and what hoses were used to attach the pump?

The stock bulkhead connector can fail too. There is an upgrade which is necessary if you run a pump larger than a 255/210 LPH. The upgraded bulkhead connector comes with the Racetronix with the 99-2002 kit. Nevertheless, replace it. The stock one is nearly two decades old. It is critical to supply voltage to the pump.

If it is a return style system, the fuel regulator in the fuel module should have been removed, since an FPR (fuel pressure regulator) is installed in the engine bay. It looks like the stock feed line was used for the feed and then it connects to the FPR on the left. Perhaps I am wrong, but appears the FPR is ahead of the rails instead of from the end of the rails. The bottom outlet port of the FPR typically feeds to a return line back to the tank. It appears yours is routed to the fuel rails

There is no vacuum line attached to the vacuum port on the FPR so it's possible the tune is still using the sloped IFR table rather than manifold referenced. But you can't assume anything, you need to know for sure.

The open line is a vapor line that runs to the tank to purge fuel vapors from the tank. The function is controlled by a solenoid on the manifold that draws vapor from the tank. The vapor line and solenoid is missing. It runs from the open line in your pic to the solenoid and then to a vacuum port just aft of the TB on the intake manifold. The open line runs back to your tank. Look like it is disconnected and removed and the tank is venting to atmosphere - maybe. I think there is a solenoid at the rear too, near the tank. Perhaps the 99's are different than a 98.

Pic below shows what the hose/line looks like - wrapped in insulation tape - follow routing into the intake.




The Racetronix 99-2002 with wire harness kit is adequate up to about 550-600 HP (gasoline).

https://www.racetronix.biz/customkit...sp?kc=rfpk-001

I've had the kit. It supported 565 to the wheel at just south of 80 percent duty cycle with 60 lb Mototron injectors at 58 psi - FI ATI D1 at 8 psi.

So you need to determine:

Current pump?
Do you have a hot wire kit or not?
Has the intank FPR been removed?
Where is the return line from the rails back to the tank?
What fuel filter - god forbid there is a C5 filter since you have an FPR in the engine bay as well?
Is the vacuum line for the FPR missing or disconnected from the intake?
Are you going to leave the vapor cannister system disconnected? Is the vacuum port on the intake plugged or open since the line to it has been removed?
Is the fuel hose in the tank correct material or is it rubber. It might have collapsed.
Need to check your liquid filled pressure gauge for a vent. If it has one I think the gauge and fpr needs to be mounted so when the liquid in the gauge expands air can vent from the port - but perhaps I am wrong on that. Or it might not have a vent.
If there is no return fuel line, IMO you need to install one - 6an - 3/8.
What is the pressure currently on the gauge when running?
What is the pressure at the rail?

I have sent you a 1/2 dozen links that are helpful with regard to your FPR, how it should be plumbed, etc. Obviously you know that you don't want to destroy the LS3 because of a bad installation or modification to your fuel system. IMO I wouldn't drive it until you get answers to the above questions.

There are several 99-2002 Racetronix fuel pump installs on YouTube.

 

Walbro 255 will work too.

 

416 LSA/LS3 in my 99 T/A with a Racetronix 255 and the hot wire kit. I've been told the set up is good to ~550whp to 600whp as well. It's an excellent set up for the cost.



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