Changing a return into a returnless fuel system?

[MR22ZZ]

This is a bit of a curly point that has been bugging me about my upcoming 4A-GE to 2ZZ-GE conversion in the AW-11. The 4A-GE has a return system where as the 2ZZ is returnless. How much is involved in changing between the 2?

The guy in the US who has already performed the same conversion made some modifications to the AW-11 pump but I was wonderring if there was a simpler way?

Also, I want to run a surge tank as well and, as the surge tank is beyond the fuel tank pickup, can this still be done with a returnless system, or do you need an intank surge tank so to speak?

[oldcorollas]

you will use the 2ZZ pump and ECU control?

can still run surge, just need a pump to keep surge full, and then usual 2ZZ pump to draw from the surge. surely?

[MR22ZZ]

I thought the same thing about the 2ZZ-GE pump but I'm not sure if it fits. I think it may just be the support that holds it in place in the tank that is the wrong shape so does not seal up correctly in the MR2 tank. I'm sure there is a way to switch the 2, will have to look into it more once I find a broken celica I can play with.

For the surge tank I was thinking the same. Use a lifter to keep fuel circulating into the surge tank but I was worried about the size of tank needed to house the 2ZZ-GE pump.

Oh well, I guess I'll find out more one I get all the bits together.

[psychofox]

all the engine management cares about is that there is a constant rail pressure. you have a couuple options that I can think of.

1. As you already thought you could try and transplant swirl pot / fuel pump assembly from ZZT231 fuel tank and install in the AW11.
2. Do a surge tank setup and run the AW intank as a lift pump to the surge and use the 2ZZ pump to the Engine.
3. Make the fuel rail on the 2ZZ to include return and run a malpassi or similar to set the rail pressure to the specified pressure (55psi from memory). This way you make no mods to the tank, etc, but you need to modify the fuel rail on the 2ZZ.

I think 3 would be easiest to do, and yield the same results in the long run. 2 well this might be ok, but now you are running 2 fuel pumps - I don't know of many people having surge with the stock AW setup.

[The Real Roadrunner]

you could set it up like 3 in psychofox's list by leaning the vac line off the reg to hold a solid value at all times but you will need a good quality pump to take the abuse.

cheers
linden

[psychofox]

I've heard the Denso Supra or Bosch pumps quite good that sort of application? Or would you need something like an SX or Aeromotive?

[MR22ZZ]

I was actually thinking 2. would be a good option as it avoids the stuffing around with finding a pump that would hold the right pressure like Linden suggested.

As for surge tanks in an AW goes, it's more a precaution, GUN METAL has one in his AW which looks nice and neat in the space left behind in the engine bay after his battery relocation. I had fuel surge issues in the corolla at the track, but that was more corolla related than anything as the tank was not designed to take close to 1G loading. This thing will take more g's than the corolla ever did when I'm finished, and the AW fuel tank is pretty small so I just want to make sure everything is well protected.

you will use the 2ZZ pump and ECU control?

realised I forgot to address the ECU, I will be using an Apexi PFC so there is an allowance there to be able to modify the rail.

[Benno]

how bout running a nomal lift and surge tank set up with supply pump and T in a regulator just before the fuel rail(or even just after the supply pump). it will still hold pressure in the rail and allow fuel to cycle just not cycle through the rail.

[JustenGT8]

KISS mate, just run a fuel reg and return line

[brett_celicacoupe]

you could fabricate a surge tank that the 2ZZ pump fits into and then plumb the AW11 line into it

[MR22ZZ]

you could fabricate a surge tank that the 2ZZ pump fits into and then plumb the AW11 line into it

yep, as stated in option #2

currently my preferred option.

[brett_celicacoupe]

oops, didnt see it.

you might not get much volume left after the pump (and filter?) goes into the surge tank.

[brett_celicacoupe]

while we are on this topic of non-return spec fuel systems, do they have a 0-5V analogue pressure sensor somewhere?

[MR22ZZ]

oops, didnt see it.

you might not get much volume left after the pump (and filter?) goes into the surge tank.

it doesn't need a large volume, it just needs to stay full. If it is roughly the size on the 2ZZ-GE fuel pump and attachments, which is an in tank style pump and filter, the surrounding volume of the pickup lines should be sufficient.

while we are on this topic of non-return spec fuel systems, do they have a 0-5V analogue pressure sensor somewhere?

that, I do not know. I would assume there would be a pressure regulator somewhere.

[MR22ZZ]

here's the US guy's solution, modification of the AW-11 pump with a fuel pressure regulator added to the system.

http://www.cardomain.com/ride/2255550/3

http://www.mr2oc.com/showthread.php?t=212316