Hello all,

I am currently in the process of swapping an 05' 6 port msp with 6spd into my 1986 corolla (ae86)

The motorset I recived was from a roll over car with 27K miles on it, I got everything with the motorset needed to complete a good swap. Complete harness, i mean COMPLETE every wire from the 8!! along with the cluster, pedal assembly, and complete fuel tank.

Here is the OG thread on my local yote board.
http://www.aztoyota.org/ilovewhatyou...hp?f=10&t=1663

Aside from the fun, back to buisness.

I need to know how the factory fuel pump circuit operates. I removed the fuel pump and secondary pick-up from the split side of the tank to inspect how the pump works.

I am planning on running the RX returnless pump in my factory 86 tank.

Upon dissasembly of the pump/pick-ups and inspection I belive I have a good idea how this sucker works. I just need a little verification from you guys in the know.



Now here is my theory...
I know without photos of the dissasembled "non servicable" fuel pump its going to be hard to understand but use the diagram to support my theory all you efi gurus out there.

The pump is powered into high speed operation if the auxillary fuel level sensor reads empty. At that point, the fuel pump is driven to a pressure in high speed operation beyond what the fuel pressure regulator is sprung for and the returning fuel being pushed past the regulator is sent to the far side of the tank using a crossover tube between the tanks. Once the auxillary fuel level sensor is happy with the level the circuit is ran on low speed and operates normally.

Sound right?

If that is right, and the fuel pump normally operates on low speed opertaion it would just be a matter of running Y block in tank with the regualtor in line with it all mounted inside of the tank.

 

The switch from low to high is dependent on load And has nothing directly to do with fuel transfer..mostly only noise at low load

The fuel transfer is from a venturi that runs off excess fuel bypassing the in-tank fuel pressure regulator

there is really no reason to run the pump at slow speed.....so you don't need to worry about it

Unless the tank in the AE86 is a split saddle tank like the RX-8 tank you shouldn't need the fuel transfer option anyway.

The fuel system in the 8 sucks stock.....you might as well do it right.........and use something else

 

So if I run the pump solely on high speed operation I should be good to go? Or do you think the ECU would throw a fit? And no, the stock 86 is not a split tank.

As long as i dont mess with anything that would force the car to run in open loop operation im not worried about emissions codes etc. and plan on running the OE fuel and ECU

Im not planning on any performance upgrades aside from a fabricated intake and possible header.

Anywho.. thanks for the input.

Im sure i'll be on here with plenty of questions down the line. This project is going to be a handfull as there is much fittment issues and such. But... I guess it comes with the territory of being the 1st.

 

ECU doesn't care if there is anything connected to a lot of the outputs....

I use the stock pump output to trigger the relay on my altered system and it works fine