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FC Fuel Starvation

Old 08-17-06, 08:16 AM
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FC Fuel Starvation

Hey gang,

I'm having a slight problem with fuel starvation during hard left turns (eg. turn 4 at VIR). The car is a '91 stripped down with coil overs and running DOT track rubber (essentially ITS prep level).

The problem is that the fuel gauge reads a hair under 1/2 when it starts happening! So either:

a) this is normal, I have to learn to keep the tank full, or

b) the gauge is off and I have less gas than I think I do, or

c) there is an issue with the fuel pickup.

The car is fairly new to me - only two track weekends so far - so (b) is a possibility. It's not a streetable car, so I can't run it around for a week and check the fuel levels at the gas pump.

So have any of you track guys run into this problem with your FC?

Thanks,

-bill
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Old 08-17-06, 10:21 AM
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Baffled tank or a surge tank would fix that.

I forget if FC's come baffled or not but Id bet that they've worn down over time by now if they did.
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Old 08-17-06, 11:05 AM
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FC tank is somehow baffled, but not enought.

http://rx7cz.net/photos/workshop125/

I end up building surge tank for my FC :

http://rx7cz.net/photos/workshop140/
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Old 08-17-06, 03:43 PM
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Bill,
I have a stock tank in my ITS car. I can usually run it down pretty low before it'll starve on me. IIRC, I can put around 14 gallons in if I run it down to where it stumbles. That means around 4 gallons left in the tank. It will starve in the left turns first. The good thing is that with the stock tank, it will at least make it back to the pits after it stumbles.
IF the stock gauge is showing this at 1/2 tank, it is off a little. I have an aftermarket gauge, so mine reads a little different.

Jim
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Old 08-17-06, 04:12 PM
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My fc drift/track car had this problem also, with about 1/2 tank or slightly more, it would starve. I made a surge tank, and plumbed it in, now i can run it till the gauge shows its almost empty and have no problems...
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Old 08-17-06, 06:29 PM
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My 1987 car also starves under hard cornering but only about 1/4 tank
or below. You should check pics of your car and see if it is leaning heavily in turns,
you may need to increase roll stiffness/run more bar.

-Jack
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Old 08-17-06, 07:12 PM
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You might have a classic FC problem, the fuel filter "sock" on the fuel pump can cause starvation while turning left. Try replacing it, it just might be the problem. That certainly solved my left hand turning fuel starvation issues.
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Old 08-18-06, 11:20 AM
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The baffling in fc tanks has been known to deteriorate, especially with cars that have sat for a long time. Not a rare problem at all.

Surge tank or fill'er up.
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Old 08-19-06, 11:39 AM
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Originally Posted by RX-Heven
The baffling in fc tanks has been known to deteriorate, especially with cars that have sat for a long time. Not a rare problem at all.

Surge tank or fill'er up.
ive seen the fd tank baffles fail due to hard cornering....
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Old 08-19-06, 10:28 PM
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I had the same problem, then changed the fuel pump sock. It was 2/3 covered with 'silt'. I also had to clean out the bottom of the pump can. This totally fixed it.
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Old 08-20-06, 09:03 AM
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Thanks for all the feedback guys. I have one more track weekend planned this year (three day PCA event at VIR) so I'll check the pump sock before then.

I have an extra tank on my spare chassis that can be swapped in if it's a baffle problem. If all else fails, I'll add the surge tank (probably the best long-term solution in any case, but also the most time and $$ ).

Thanks again,

-bill
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