EFI in an ATV...

[Overkill]

Mike, I've put Fuel injection into 4 different jeeps. The set up I'm running in mine is a fuel cell with baffles in the center of the cell. The baffles look like 2 boxes with one wall missing. [ ] Over lap the front and back walls leaving about a 1/4" gap. As the fuel sloshes back and forth it fills the baffles. I use a frame mounted fuel pump out of a ford F-150 truck, with a screw on filter on the bottom of the fuel cell. You can also use a in tank GM pump in the center of the baffles.Both pumps produce 45psi, and can be bought at any napa. I don't think the foam is going to work off road. It will slow the sloshing down, but in off camber situations you will still end up with all the fuel on one side off the tank. Baffles will trap and hold fuel around the pick up.

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[hydromike]

The only issue with the baffles is that I really have my heart set on using the poly tank in the Attex. I'm sure they'd work well though. I'm not as worried about off-camber situations as I am with just generally bouncing around. I can keep enough fuel in the tank to make sure the pickup is always submerged with the foam. Keeping that same amount of fuel in the tank with sloshing will allow bubbles to get around the pickup. We'll see how it goes with the foam.

If it doesn't work, I'm going straight for L'il Rhody's idea of the dual tanks. I came up with pretty much the same idea of the twin tanks, but I was missing the critical step of having the return line go into the second tank. Absolute genius. I just don't know where to put the second tank, and how big it'd have to be. Probaly a 1/2 gallon aux. tank would work. It could basically be a small poly box with 2 inlets and an outlet. Hmmmm.... more thinking...

thanks again for all the responses...
~m

[liflod]

If my kids had a pack of matches at the time, we wouldn't have to deal with your problems

[orange crush]

for what it's worth

I had a problem sucking air on my suzuki samurai when I installed an EFI v6. I solved the problem by installing a low pressure electric pump from the tank to an oil filter style fuel filter (ie marine). The filter mount utilized a supply in and a return to the tank for continous flow and bleeding of air. On the other side of the mount was fuel out to the engine where I mounted my high pressure inline pump to the engine. This also provided great fuel flow at absurd angles.-Brent (Don't have a profile up yet but will soon with my Sierra trail boss)

[Bw6]

Cavitation

I don't know if you solved your problem but when I first read your post I thought it may be fuel cavitation. You have probably addressed these points but here is a check list.

COMMON PROBLEMS WITH FUEL DELIVERY SYSTEMS.
* Do not mount an EFI electric fuel pump so it has to draw fuel from the tank. This creates a negative pressure in the fuel line allowing the fuel to boil at a lower temperature.
* The pump must be mounted in the tank or in a location so that it is gravity fed.
* If the fuel rail is too small and you have large injectors, this can create a pulse in the fuel rail allowing fuel starvation on some cylinders.
* Fuel should be pushed through the fuel filter. Pulling fuel through a filter can cause cavitation. If a filter is to be used on the inlet of a rail mounted fuel pump, a filter rating of 160 microns MINIMUM should be used.
* It takes approx. 1/2LB of gasoline to support 1 HP. This is commonly referred to as a .5 BSFC. You should always err in the safe direction of larger when sizing your injectors and fuel pump

[x.l.r.8]

there are 2 things `i would do if not already done, 1st is a return line, this will help circulate the air back out as hopefully the path of least resistance will be the return line (you can put jets inline to regulate the return fuel flow. Then i would also make/buy a swirl pot, this is used on our rally cars for this very reason, this will also act as a sump so you have a deep well to syphon your fuel from without worrying about air when it's being shaken up.

[mad_max_500cc]

hey mike another question for ya. the return line that goes back into the tank does it enter at the top and just shoot a stream down into the tank cavitating the the fuel? or do you have an extention on it going to the bottom? between fuel slosh and cavitation you could have a couple of things going on at once! the foam from a fuel cell sounds like a winner of an idea!