Outer Limits 4x4 Board

I'm in the process of installing a MPFI setup on my carby vitara engine. Planning to use a VL electric fuel pump for fuel delivery. i have searched but not found an exact answer.

My question is can i use the existing hard fuel lines just replacing the soft lines at either end with efi fuel hose. If so would it be better to use the breather line as the new return line since it's larger in diameter and the old return line as the new breather line?

A) yes just use the stock hard lines

B) I guess you could, I've always used the existing lines for the same job as the vapour line has no barbs to retain the soft line.

Steve

yeah, the old ones are ok. but the breather line is much more sutible.
i just used the originals but when i go turbo, im gonna get some huge ones.

i have some pics of how i mounted the pump and filter if you want?

You can flow hundreds of horsepower with an 8mm line... how much fuel do you need?

I don't think a fuel line with no barbs on it is "much more suitable" than a line with barbs.

Steve.

If the effort i had to put into removing fuel lines today with no barbs is anything to go by, then barbs are overrated.

I'm running standard fuel line with VL pump , and it gives 28 PSI , have had no trouble with hills or angle's , Cheers Paul.

Ok looks like i'll be using stock lines.

Cheers
Geoff

Gwagensteve wrote:You can flow hundreds of horsepower with an 8mm line... how much fuel do you need?

I don't think a fuel line with no barbs on it is "much more suitable" than a line with barbs.

Steve.

the feed line is 8mm, but the return is about 4mm. should be at least 6.4..

and im not gonna risk a lean out, mid race. hence why i will upgrade.

a smaller return will increase fuel pressure if anything , so no worries of a lean out there ..

X2.

Can't see how a smaller return could contribute to a lean out.

I've built 5 EFI cars with the stock return as the EFI return it's never been a problem.

Steve.

mines sameish

g16b mpfi

i am using the original vit fuel line that came with my motor up to the tank. this is same size as main zook fuel line. i am using the orig line as the return line back.

standard rubber lines for meee.. vl pump. no probs, just have to use proper hose clamps in the ends and make sure the normal lines arent stuffed.

Gwagensteve wrote:X2.

Can't see how a smaller return could contribute to a lean out.

I've built 5 EFI cars with the stock return as the EFI return it's never been a problem.

Steve.

ok, my plan is...

high performance in tank pump, with internal surge tank, with 3/8 feed line and a 5/16 return.

back pressure in the return line will give you a varying fuel pressure, going from high at low revs/load to low at high revs/revs. which probly wont be a problem with the microtech, but i want to do it properly.
the less variables the better it can be controlled.
money is not easy for me to get, so i only want to spend it once.

my aim is 200hp+

crackatinny wrote:

Gwagensteve wrote:X2.

Can't see how a smaller return could contribute to a lean out.

I've built 5 EFI cars with the stock return as the EFI return it's never been a problem.

Steve.

ok, my plan is...

high performance in tank pump, with internal surge tank, with 3/8 feed line and a 5/16 return.

back pressure in the return line will give you a varying fuel pressure, going from high at low revs/load to low at high revs/revs. which probly wont be a problem with the microtech, but i want to do it properly.
the less variables the better it can be controlled.
money is not easy for me to get, so i only want to spend it once.

my aim is 200hp+

erm dont you use a fuel pressure regulator to keep the pressure in the fuel rail constant , or rising rate for turbo ?

the ecu is only as good as the person that tunes it ..

11_evl wrote:he is running microtech so he will need all the help he can get.
id leave the lines how they are so u can blame something other than the microtech

sounds like someone likes to blame other problems they cant diagnose on a microtech

like what ?

ive used microtechs and produced the highest hp n/a swift around and theres no issues with the ecu ...