Ke70 Fuel Injection Question Vl Fuel Pump

[rhys2229]

hey i'm in the process of gathering parts for a 4k to 4age conversion,

i need some info on the fuel pump and lines, i'm thinking of using a vl turbo bosch style electric pump (probably cheapo copy), do i need to use a lift pump in the tank as well? or can i just run the electric fuel pump straight from the tank (after a fuel filter)? and where do i get the metal fuel lines from the tank to the engine bay?

 

thanks

[kiahn]

OPTION 1:

6mm lines for feed and return

bosch 044 (VL Turbo) fuel pump

standard ryco efi fuel filter in engine bay and an inline one before the pump

DO NOT expect it to supply fuel when running under 1/4 of a tank

 

OPTION 2:

6mm feed and return lines

lift pump into the swirl pot with filter before the pump

then a bosch 044 to a filter then to your engine

 

 

2nd option is harder but 100 times better as it wont cut out under heavy right hand corners

[rhys2229]

is the tank in an ae71 different from a ke70 because my mate has just a vl external pump and it seems to run ok without a surge tank and lift pump,

[ke70dave]

ooh ooh i can answer this!!

 

currently re-hashing my fuel system at the moment.

 

i ran my 4age on just a bosch 070 (vl pump) external fuel pump (no lift pump) for a few months. it did run well, but after about 45mins the pump would get VERY noisy, and it would drive me up the wall. high pressure pumps are not designed to suck fuel, so i think they start to cavitate after a while. also contrary to popular belief, if i drove sedately i could run my fuel tank REALLY low (fuel light on for yonks....) without it surging. it was only when i got "enthusiastic" that it would surge.

 

i then installed a surge tank setup, and made this tech article:

 

http://www.ae86drivingclub.com.au/forums/s...read.php?t=8255

 

have a read.

 

i have had that setup in my since that tech article (a little over 8months). been going great. however i believe my lift pump has died/is dying. so thus i am changing my setup a bit.

 

i am going to install a lift pump from the VL commodore inside my tank. the standard VL setup is a lift pump inside the tank, which feeds the external high pressure pump. this means that the lift pump must flow more than the high pressure pump (for your information the bosch 070 flows 130L/hour @ 3bar).

 

what i am going to do, is use this internal fuel pump to fill up my surge tank. and the use my bosch 070 from the surge tank to the engine. and because my lift pump will flow more than my high pressure pump, i will be able to put the return from the engine straight back into the tank. this should help with fuel heating issue (which i suspect i had as well....) but since i have a surge tank between the lift pump and the high pressure pump that should stop any surging issues.

 

here is how to install the lift pump into an ae86 tank (should be similar to ke70 i'm hoping):

 

http://www.rollaclub.com/faq/index.php?tit..._AE86_Fuel_Tank

 

so in short.

 

buy a lift pump (mine cost 91$) buy a small surge tank (mine was 99$) and say good by to surge issues, and hello to a nice neat fuel pump setup. and just use the standard metal lines, they are big enough.

 

also in response to kiahn. do not use a bosch 044. they flow 200L/hour @ 5bar. it is an absolute complete over kill (standard jap ae86 has an 80L/hour pump) i ran one in my car recenently trying to diagnose a problem, and my fuel pressure regulator could not handle the flow and also it was heating up my fuel sooo much that i was getting a vapor lock issue (google it, its very interesting). my fuel was getting so hot that my surge tank was essentially untouchable after a 30min drive.

Edited January 12, 2010 by ke70dave

[rhys2229]

where did you buy your surge tank? ebay have alot but most are probably too big as they hold 2 litres. do parts shops stock them?

[ke70dave]

i bought this one

 

http://www.tweakit.net/shop/product_info.p...h623r2dq3ab3tt0

[rhys2229]

and how did you wire up the two pumps? from the battery with a fuse?

Edited January 16, 2010 by rhys2229

[ke70dave]

circuit opening relay with the ECU.

 

have a google around, its the standard setup for the 4age. ensurs your pumps turn off when you your engine turns off.

 

wire them both off the same output. just make sure you use a chunky main power feed.