Fuel System Q - 20v 4age EFI sierra

[dank]

Hey guys,

If I pick up a vitara tank with in tank efi pump, will this be suffient to run my 20v 4age engine keeping in mind its the same capacity as a G16b but a little more power?

Or a coily sierra tank with vitara efi pump installed...same deal...
????

[crackatinny]

essentially yes, a efi fuel system is designed to be too much for the particular engine it is designed for.

[oozuk]

yes to a point, and you will also find in those tanks that they have a swirl pot around the fuel pump pickup, but if you find that it's not keeping up pressure under full load then install a walbro intank fuel pump replacement, I'm running an x-90 tank in my sierra (same a vitara EFI)
and that's what i plan to do when money and time permitts for my vit 1.6L turbo

[dank]

[GRPABT1]

Considering the power those 20V motors can make I wouldn't risk it. It's not to expensive to buy a surge tank and external pump and just use the stock in tank pump as a lift pump.

http://www.tuffcarparts.com/store/ (site is down atm but in the past I have bought stuff of this site at very good prices)

[Gwagensteve]

I don't like external swirl pots and pumps in 4WD's. A possibility, if you really had to, would be a compact rectangular one, (I think Advan performance centre in Sydney make them) these are designed to sit behind the back seat in skylines and hide under the boot trim. They have the pump/s piggybacked onto the tank. In a Sierra, this could be mounted in front of/above the rear axle, opposite the muffler, and not ruin the limited load space you have.

I've seen three sierras with swirl pots/feed pumps. One was hideously noisy (as in louder than the motor at idle) but still had some interior room, one had about 1/3 of the interior room taken up by the fuel system, and the other had no load area at all.

My hate for them stems from a number of areas:

A) we're never running enough power to warrant multi pump systems - that is, more flow than a single in tank pump can deliver. Name a sensible power figure and there's an in tank pump that will flow enough to suit. I was looking at a Mitsubishi 380 in tank pump the other day and it's less than 1/2 the size of a vitara pump and flows over 200Kw of fuel.

B) We don't have a boot to put the system in, it's either under the car in the mud or in the cabin with us

C)I've built/reworked about 5 efi suzuki's and have never, ever seen one have problems with fuel delivery regardless of angle with a stock vitara pump in tank.

D) There's about three times the hoses, connections, and extra pump, (along with relay etc) the tank etc all to raise potential problems. some of which could be very very serious if that stuff is in the load area of a sierra.

I don't know what the 4AGE fuel pressure requirement is, and it may be that a suzuki pump can't do the job, so I'd just go for a bigger in tank pump. You'll need an adjustable fuel pressure reg and pressure gauge anyway to know if your fuel pressure is right for the 20V so you can check the system.

Don't get swayed by all the bling. you'll still be running a stock motor that was fuelled by a stock in tank pump in the corolla that motor came out of.

Steve.

[dank]

Couple of good points there steve. My concern is definitely space. If an intank pump can do the job I see no point in filling up the boot with excess crap. In the line of keeping it simple my goal is also an intank pump.

problem is suziworld are the only ones stocking coily sierra tanks for 220 . I can get a vitara tank for $130 but need to look at fitment issues. Do they fit ok in the stock location on the swb?

[Gwagensteve]

Yes - here's a couple of photos.

Exhaust clearance is tight but no real problem.




This was acutally an X-90 tank. (same as vitara)

Careful what tank you get though, you need a 1.6 EFI SWB tank. The LWB tanks and all 2.0 tanks are too big to go in the stock spot.

Steve.

[dank]

picking up a tank on monday from the wreckers, swb vitara efi, without EFI pump, as I'm going to drop in a more powerful ~500hp pump...overkill but better than an underperforming pump. Lots of choice on ebay from bosch copies to the real thing.

Would these do the job?
http://cgi.ebay.com.au/WALBRO-USA-FUEL- ... dZViewItem

http://cgi.ebay.com.au/Commodore-in-tan ... dZViewItem

http://cgi.ebay.com.au/Fuel-Pump-Intank ... dZViewItem

[Gwagensteve]

I'd get a genuine bosch pump.

Don't go crazy oversize, you'll only have to feed it lots more amps and all that flow won't do a thing.

Steve.

[Drew]

go the walbro pump ,it will work fine with the 20v.

we use heaps of them at work with no problems so far.

better to have fuel flow in reserve than not enough.
the factory 20v reg will work

[dank]

hey Drew, thanks for that. I am finding out new things every day!!!

[GRPABT1]

A VL commodore turbo in tank pump is a commonly used cheaper alternative for some after market pumps.

[Drew]

not being a smartarse but the vl turbo intank pump is a low pressure lift pump the high pressure pump is external & also a commonly used performance pump for import conversions etc.

[GRPABT1]

Meh well there you go, I knew one of them was :p

[Gwagensteve]

go the walbro pump ,it will work fine with the 20v.

we use heaps of them at work with no problems so far.

better to have fuel flow in reserve than not enough.
the factory 20v reg will work

This is an interesting point Drew. I'm sure you're right, but here's an experience of mine that has proved that stock regulators might not always do the job.

My 660 engined sierra had a bad cough on gearchanges and was running insanely rich. I'd been putting up with this for ever, but eventually lost patience with it and decided to do something, so I fixed my dodgy return line, which I though might have been raising fuel pressure.

I ran a wideband A/F on it and proved yes, it was still insanely rich.

I've removed the stock regulator and fitted an aftermarket reg and solved the problem. I don't know exactly why, but it's possible the stock 660 reg couldn't flow enough fuel for the vitara pump I have and rail pressure was too high as a result. (additionally, vitaras run higher rail pressure anyway)

It would seem to indicate it's possible that a very high flow pump might outflow the reg and lead to rich mixtures.

Just something to look out for. Yes, you can put a fuel pressure gauge on the feed but with a stock reg you can't adjust it anyway so It's probably worth going to an adjustable reg if you suspect a problem straight up.

Steve.

[MightyMouse]

Steve's spot on re the pump / regulator issue.

Change the pumps characteristics too much and the regulator isn't going to be happy.

A overly large pump will overwhelm the regulators ability to hold down rail pressure, whilst a large regulator and small pump can lead to pressure oscillations as the regulator doesn't operate linearly but in an on/off fashion ( this is rare but have seen )

IMO run a matched pump / regulator pair - a 500hp pump needs a 500hp regulator ( and matching supply AND return lines ).

Also be careful of pump constructions especially if there's a chance of running dry. Turbine style pumps are much more tolerant of fuel starvation than are roller cell units.

And lastly ... running a huge fuel pump eats into your electrical capacity for no purpose. Some draw more than 15 Amps and if its not needed, why bother ?

[dank]

great discussion guys. More tech than I know what to do with! Everyone is making valid comments and Mighty MOuse what you say makes a lot of sense. I'll do some more homework and find a pump that was a similar size output to the stock one.

[Gwagensteve]

Or maybe go straight to the source and get a pump from the right model of corolla- It will potentially save a lot of stuffing around.

As an aside Dank, I was looking at the induction system from your 20V motor and that airbox is going to take a lot of work to get right. (that is to seal effectively, fit in the and still make power)

Steve.

[dank]

I'm going to see how it goes once I get the body back on and everything else sorted. I'm not sure yet whether I will actually use that airbox or get the AFM mated onto a custom alloy setup. something else to think about further down the track...