4AGE losing fuel supply round corners & when low fuel in tank

[Sidey]

4age losing fuel supply round corners & when low fuel in tank...
AE86 has a standard ADM fuel tank and VL fuel pump.

If the tank is full or near full there is never a problem.
Example 1: at half full tank, round a sweeper bend, fuel supply gone (wouldn't be good for injectors), any throttle just does nothing, then give it a moment once straightened up, supply returns and all ok.
Example 2: approachin an low or Empty fuel tank, only gentle cornering can run out fo fuel supply, and even strong acceleration will run it out of fuell supply till reduction of throttle .
I'm sure there are baffles in an ADM fuel tank.
there is no surge tank fitted but i know there are other ae86 adm 4age that don't use a surge tank or a jdm fuel tank.
my best guess seems to be to do with fuel pickup from tank ?
long term problem, never found solution.

Someone else would have experienced/solved this problem with their converted 86 also?

whats been done so far:
metal fuel pump replaced
shifted the fuel pump to higher and lower position and different angle.
ive inspected the flow from the pump, but this wouldn't be the problem because when car has full tank, no problem.

Thanks for any advice.

[ke70dave]

thats called fuel surge, and the only proper way to fix it is to use a surge tank

you really need to install a surge tank, when using a fuel tank that wasnt originally used for EFI (your current one is for carby engine, the carby has a fuel bowl in it which acts as a sorta surge tank i guess)

search around for "surge tank" there are a stack of threads on it

this is how your setup is now



this is what you need



using something like this



and in the end it should look something like this

[Sidey]

Thanks for the thorough reply KE70Dave! i see u or someone u know has been through this, if so how much did it cost all up (lines, clips surge tank, fitting etc)
also will need another low pressure fuel pump too i notice, that right ?
one thing i didnt catch was what volume tank is enough to recitfy the surging for this setup. 500ml enough ?
yeah i did suspect a surge tank would fix the problem
some other adm ae86 4age's seem to get away with it though ive heard?
the other thing i thought was to improve the baffling in the tank - difficult.
and replacing with jdm tank - expensive.
so your suggested way seems best.

Placement/Positioning is important and height may be important, so i'll get someone to do this for me, and it should be professionally done since its dealing with petrol, not something you can afford to get wrong.

Also, the vl efi fuel pump was installed in the engine bay... that an issue ?

[ke70dave]

nah i havnet actually done it in my car

i don't have enough cash flow to play with this kind of stuff

ive helped a few mates make a setup like this.

its quite an expensive exercise (maybe 300$ or so for everything), but i believe its well worth the effort, reliable and consistantfuel is what an engine (and a driver for that matter) likes.

i think about 500ml should do the trick, mabye a tad more to be on the safe side, woudlnt want to go much over 1L though for an NA car, turbo maybe different. essentially you can never have to big, but why spend extra cash when its not needed (and room as well, its hard enough fitting a 500ml one)

you mention that the fuel pump is in the engine bay, i would say this might be a contributing factor, as the fuel pump is having to "suck" fuel all the way back from fuel tank. I'm not exactly sure, but id have a safe guess that this wouldn't be optimal!, as air bubbles would have to be "sucked" through the fuel line (when the fuel splashes around at low levels). and high pressure fuel pumps don't like sucking air. maybe try mounting the fuel pump as close to the fuel tank as possible?

a JDM tank is a good option, you can pick them up for about 200$ or so from time to time, its got all the baffles ready to go. if you are after an easy solution then this would be the way to go (its not a dodgy solution by all means)

but if you are after a solution that will solve all your fuel problems (with in reason) for ever, then i would be inclined to go the surge tank setup. and if you decided to upgrade to turbo, or even get some nice goodies for your N/A, you wont have to worry about fuel system.

[Sidey]

so its actually cheaper (if keeping the motor standard) to go for a jdm tank (plus you get a low pressure fuel pump built in) along with the better baffling.

but theres not a heap of them around in australia i think, but they are prob imported over by jap parts importers regualrly

maybe its worth loading a WTB: jdm fuel tank in the Wanted to Buy section u reckon ?

i thought i was sure that not everyone with an adm ae86 with a 4age conversion used a surge tank, so does that mean that all the others run a jdm fuel tank ? sounds suprising if so.

[ke70dave]

i think most of the guys that don't run surge tank keep the fuel level above 1/4.

i could be wrong though, anyone care to let us know what you ae86/4age boys do?

[Gilly]

in tank pump and don't let it go below 1/8ths normal driving, you'll still have surge at 1/4 with an intank pump when cornering hard.

[Sidey]

<div class='quotetop'>QUOTE (Gilly @ Mar 28 2008, 03:35 PM) </div>you mean an in tank pump as is in the pump that comes built into the jdm fuel tank ?

Ke70dave, i reckon you're right. i reckon a lot of us just keep the tank around 1/2 to full and sometimes down to a quarter if we have to.
yeah wonder what more of the others do for their setup...

[egg_83]

A intank can be put in any tank. Its just a pump that is inside the tank like skylines and s13.

I just keep mine above 1/4 and no problem

[Vezza]

I was thinking of cutting mine apart and welding in baffles and simply making a larger intank fuel pot, should be cheap and effective... as long as I don't blow myself up cutting up the fuel tank