ZUKIWORLD Online | Suzuki 4x4 Editorial and Forum
ZUKIWORLD Discussion Forum => Technical Discussion - Performance / Modify => Topic started by: Bear76 on August 12, 2011, 07:17:55 AM
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While researching what needs to be done for this I noticed a differnce of opinion as to the use of a FPR or just a bypass filter. I can understand both sides. My question is can I just use a T close to the carb, with one side acting as the bypass back to the tank and just run a low pressure pump? I would guess that the needle in the carb would close when the bowl is full and as long as I dont overwhelm it with too much pressure all will be fine. The tee would let any extra fuel pressure run back to the tank.
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The issue with running a t is that the fuel will take the easiest path possible, which is the unblocked line back into the tank. If you make the return line small enough and put a pressure regulator on the line to your carb it might work, but you risk your carb running lean.
I am running a low pressure in-line pump and a fuel pressure regulator, both designed for an old carbureted v8, at 3.5 lbs. The only time I run into an issue is if I let it sit in one place idling for 5 minutes or so, the fuel pump starts to make some noise as if it is cavitating. Probably because I don't have enough fuel going through it to keep it cool. But it has never been an issue and has worked fine since installation.
If your running the stock fuel pump it already has fuel bypass built in, just toss on a pressure regulator on there from your local autozone and call it good. :)
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I'm going to running an external pump, all the original stuff was done for when I got it. I was looking at bypass regulators too but they are 2x the price. Is there such a thing as a external elec. bypass pump?
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My question is can I just use a T close to the carb, with one side acting as the bypass back to the tank and just run a low pressure pump? I would guess that the needle in the carb would close when the bowl is full and as long as I dont overwhelm it with too much pressure all will be fine. The tee would let any extra fuel pressure run back to the tank.
This is exactly how Suzuki did it on the 93 Swift that I have - a low pressure in tank pump feeding an Aisin carburettor via a T with one side of the T feeding a return line to the tank, and no pressure regulator - I'd guess the feed to be around a 5/16 internal line and the return probably 3/16", so it is slightly smaller.
I've never had any lean running issues, nor have I heard of any.
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You could put a 3/16 restrictor in the return line and check the pressure
with a gauge, if it isn't right go bigger or smaller to suit.
The old Hillborne (sp) injection systems used a "button" to change the
fuel pressure to tune the injection system, smaller was richer and bigger
was leaner, because it controlled the return of fuel to the tank
Wild
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Tricky. :)
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Is there a way to run a mechanical pump on the 1.6? Is the provision still there with a block off plate? A new cam would be needed as well. Or just find a 1.3 head from a carbed year.
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1.6L engines do not have a fuel pump port, at least not here in the US,
you would have to use a 1.3L head for a mechanical pump.
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Also, I've seen the homebrew versions and I was wondering what pipe diameter does the carb take? It looks to be 1.5-2" on the elbow.
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Ended up getting a Weber instead. Thanks for the replies.