Fuel pump sucking air (was: Re: Proper Mixture)

[dzorde at aesprodata.com.au]

I built a small 5L surge tank to fit in my boot.  It was close to a half days 
work soldering up a copper tank out of a large pipe and some plate, add 4 small 
pipes for high pressure in and out and low pressure in and out.  Buy an ordinary
cheap electric fuel pump (no need for high pressure or high volume) and you are 
there.  All up about AU$60.  If you build it correctly (taller rather than wide)
it'll be way better than any new baffled tank you can find.

Dan     dzorde at aesprodata.com.au 

______________________________ Reply Separator _________________________________
Subject: Re: Fuel pump sucking air (was: Re: Proper Mixture)
Author:  diy_efi at coulomb.eng.ohio-state.edu at INTERNET
Date:    8/1/96 11:28 PM


> 
> From: FIScot at aol.com
X-ccAdmin: postmaster at guardia
> Date: Wed, 31 Jul 1996 22:54:33 -0400 
> Subject: Re: Proper Mixture.
> 
> I would not worry about what the ECM is doing.....  What about running the 
> pump dry?
> The ECM won't change dramatically in a couple seconds, and if you are on/off 
> the throttle, probably won't change at all.
> 
> I would think that running the pump dry might shorten it's life.  The Mike 
> Knell book on Chevrolet TPI and TBI Engine Swapping had a neat idea to stop
> engine from dying in this situation.  He made a little reservoir box to hold 
> fuel that fed the high pressure pump.  A low pressure pump fed the box from
> the tank.  Requires two fuel pumps, but solves the problem if you can't get a 
> baffled fuel tank.
> 
> Scot Sealander  FIScot at aol.com
> 
     
Hmmm ...  Some how I'm afraid the extra pump, its plumbing, and the extra 
wiring would end up costing more than getting a baffled tank at a junk 
yard ....  Actually, I'm more concerned about a "sudden lean condition" in 
the engine than I am about running the pump dry.  The pump (a rotary vain 
high pressure/velocity pump) doesn't seem to mind the short quick bursts 
of no fuel ...  I wouldn't want to run it long that way, as it would 
overheat, but for the short bursts that only occasionally happen I don't 
think it is a problem...
     
Thanks for the suggestion, though, I never thaught about using 2 pumps -- 
neat idea...
     
Donald Whisnant
dewhisna at ix.netcom.com