fuel system

[45aken]

hello,
what are the sprinter guys using for there 4age fuel systems?

im going to go the surge tank route, but i have 3 questions.

1)what pumps are people using (lift and EFI)
2)would you use the stock fuel pressure reg from the 4age
3) i haven't taken a look, but do all the lines from the tank to teh engine have to be changed to efi?

thanks

[roadsailing]

My setup consists of the following (running standard smallport 4AGE)

Standard unmodified carby fuel tank

Inline "VL" type fuel pump mounted on one of the fuel tank straps, don't know what brand it is exactly.

To a point, the fuel pressure is controlled by the fuel lines and fuel pressure regulator. Pumps don't
"make pressure" they "supply" it depending on system restriction. Mine seems to work fine, basically
run a pump rated at the same pressure as standard if you can, as you don’t need any more. If you can
only get a pump with a higher rating, don't worry too much about it.

I'm using the standard lines and it works fine, I have heard of people using standard lines on 4AGZEs.

If I was going to replace anything, I would fit a new 8mm delivery line, and use the old 6mm delivery line
as the return line.

Make sure you change all or the rubber hose to high pressure EFI hose, and use the proper hose clamps
(I'll post a pic of these when I get home)

You will need some reducers too, a 12-8mm (or similar) for the fuel tank to fuel pump a 8-6mm for the fuel
pump to the fuel line (or wimilar) , two 8-6mm for the fuel filter in the engine bay, a 6-4 for the return line
and a 6-8 for the fuel rail supply fitting. A decent pirtek should be able to get all of this for you.

I higly recommend using a surge tank, as I get fuel surge when I have less than a third of a tank on the
Street, and its worse on the track. I'll post a picture of a swirl pot/surge tank design and the way you
should hook up the lines.

I'm looking in to what pumps to use myself, so I will post up what I end up using.

[Starfire]

The standard fuel pump should be ok to use as a lifter. Just about any EFI pump will do the trick for your high pressure pump as the 4age isnt exactly thirsty in standard form. I believe the VL turbo pump to be a cheap and effective one for just about anything.

You can probably use the standard fuel line as a return (check that it isnt falling apart after 20 years - $20 worth of new line is well worth it when preventing a fire) but you will need to run new high pressure lines from the surge tank to the fuel rail.

Unless your 4age is highly modified there is absolutely no point changing the fuel pressure regulator. Most aftermarket ones arent as good as a factory setup anyway.

Too many people try to increase fuel rail pressure to compensate for injectors that arent up to the job. The problem is that injectors are designed to work at a specific pressure and increasing it doesnt do all that much for flow. Once your 4age is making big power then you will need to replace the injectors (use ones from a gze).

[45aken]

yeah im thinking about going for a surge tank straight away.

did a bit or research and looking into a vl inline pump (after the surge), and a carter lift pump (or any other electric carby pump) just wondering about the lift pump, are they an external or internal pump? and if internal, what model number should i go for?

alot of the boshe pumps are external, but there failry high rated (350hp+++)
i know the hose clamps u mean, there designed so they cant cut the hose.

[ae71 kid]

hey mate, i have a 20v in an ae 71( the aldo of the ae86s) and i can tell u now there are cheaper and just as effective ways of gettin around fuel surge.
I have just completed my fuel system and it consists of, modified vl pickup grafted into where my old pickup was, the vl pickup uses a 12mm metal line with a small lift pump on the bottom sucking from the very lowest point in my tank, that comes out where the old 6mm line used to and feeds directly into the rear of the vl inline pump( dont get ripped of by someone trying to sell u a vl turbo pump as they are identical to the na vl item) via 12 mm rubber hose, my pump is mounted on my tank strap, then i have 8mm line to a vl inline filter and more 8 mm line running the lenght of the car to feed the fuel rail, i have used the old 6mm carby supply line as my return! this setup will supply all the fuel u will ever need even in high hp applications and will not surge unless ur out of gas! this setup is probably the most cost efficient too as it elliminates the need for a surge tank and cost me a total of $90 to complete, $30 for vl pickup and lift pump from wreakers, $30 for vl high press pump from wreakers, $10 for my steel 8mm line and around $20 for the filter!
hope this helps
cheers tim

[roadsailing]

45aken, i'd go for an external lift pump, then you dont need to worry about getting wires into the fuel tank, simplifies it a fair bit.

external high pressure pump too.

[RobertoX]

On my last sprinter I had a goss external EFI pump of some sort that lifted directly from the tank sucking through a carby filter, then into the standard line and efi hoses and clamps all the way back to the tank (I would not run the risk of keeping any carbie hose, even on the return line!).

The pump was mounted to the tank strap with a bracket that I made. I used the std breather line as the efi feed, the std feed line as the EFI return and the std feed line as the new breather (because it turned out neater this way).

I didn't ever have a problem with surge however I never let the tank go below 1/4

On my next 4age I will definately go with an internal tank pump with a baffle welded into the bottom of the tank. Its a lot quieter (even with the external pump rubber mounted it made a heap of noise) and a lot neater, I can't see having a fuel tank modified being any more than a surge tank setup with 2 pumps required and all the extra line and the surge tank, plus all the extra hassle with mounting it and all that. Sure if you are going for a high hp setup or on a track car but not for a street car.


Oh a good tip is that if you do go for an external vl type pump then the bracket that holds the 4ac coil will hold the pump nicely.

[45aken]

im seriously looking into the madification of the tank. intank walbro pumps are really cheap, and the modification (baffels) wouldnt cost too much. might be a good idea.
just to get it running i might go to the wreckers and get a vl pump today, but do i need the pump and the lift pump (that is in the tank) from the vl, or just the pump?

[WHITCHY]

For my fuel system I just took the in tank pump out of an AE82 twinky, cut the bracket it is mounted to half way down and extended it by bolting on some stainless steel so the pickup sits right near the bottom of the tank.
The best part is that the bolt holes to mount the fuel pump on the AE82 and the AE86 tanks are identical!so once the bracket is extended it just bolts straight in with no fuss!
I dont really have a problem with surge, untill I have about 5L of petty left in my tank, and even then I need to corner really hard to get surge!
You could always try that setup, and if you get surge then just use the AE82 pump as your lift pump, and feed that into a surge tank, and then from the surge tank have a VL pump. -That is what my mate has done with his, he went and bought a $30 oil catch can from PEPS and mounted it in his boot as a surge tank, and it is fine, no fuel smell, no leaks and no surge and its cheap!
you could probably pick up a twinky intank pump for about $30 from the wreckers, and then if you are getting surge another $30 for a used VL pump, and another $30 for the catch can and use it for a surge!
Goodluck!
Cheers.
-Whitchy-

[45aken]

that sounds more like what im after, something more bolt on. might see how that goes.

[ae71 kid]

that definately sounds the goods, if i had have known that the ae82 plate has the same holes as ae86/71, i wouldnt have bothered with trying to mod my plate to accept the vl lift pump, go for that idea mate will be verry simple and effective!!
cheers tim

[45aken]

so what your sayin is i should get the entire pump/bracket/plate(im guessing this is the top plate which bolts to the tank in the boot) instead of just getting the pump.
sorry about this guys-im a complete dipshit when it comes to fueling.

[WHITCHY]

yep, the whole thing, just undo the little screws holding it in place and take it all!
then just cut the bracket holding it at half way, bolt some steel or stainless steel I cant remember what I used! just use something that wont rust if thats even an issue in a fuel tank?
and just loosley fit it in place drop it in the tank if it hits the bottom then shorten it a little bit so you dont suck up any crap from the bottom of your tank and clog the pump!

Here is a pic of what it should look like when its extended
Pic courtesey of Joel (TurboRA28)

Oh, I almost forgot, one of the lines will be facing the wrong way once it is fitted in the tank, but there is enough line to simply chop off the section facing the wrong way! you will understand what I mean when you have it sitting infront of you!

good luck with it all!
Cheers.
-Whitchy-

[roadsailing]

just a warning here,

a mate of mine converted his sprinter to EFI by using an SV21 camry swimmer pump, and his fuel surges HEAPS worse than mine (using carby pickup)

if you want to do any kind of racing, i strongly reccomend using an external surge tank.

[Wedged'86]

There's nothing like raising a good thread from the dead....
When you guy's mounted your VL pumps to the tank strap how was this done? did you drill holes for brackets in the strap?
And whoever suggested using the 4ac coil bracket to hold the pump, good idea.

Whitchy, i was going to lash out and buy an AE82 pump new but the guy wouldn't sell it to me when he found out what i was doing with it, said that running wires into the tank was dangerous... i take it that the wires that you get from the wreckers aren't included in the new one.... That'll teach me for trying to NOT be cheap hahaha.
yeah so now i'm going to VL route i was told that i shouldn't need a lift pump that's right yeah?
One more thing, should i put a filter before the pump?

Thanks alot.