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Re: Fuel Tank Venting - BASIC

To: reid.w.simmons@intel.com (Simmons, Reid W)
Subject: Re: Fuel Tank Venting - BASIC
From: Bill Gunshannon <bill@cs.uofs.edu>
Date: Thu, 9 Mar 2000 16:48:40 -0500 (EST)
According to Simmons, Reid W:
> 
> You should NOT have a substantial vacuum build up in the tank.  

I think the problem here is a matter of how much.  Which none of us can
actually express in Email.  :-)

>                                                                This vacuum
> will fight the efforts of the fuel pump and lean out the mixture thus
> increasing the RPM, 

I don't notice any effect like that and as I say I have run the tank down 
to empty on at least one occaision.  I also notice no difference in the
amount of WHOOSH when the tank is 3/4 full and when it is nearly empty.
I also have the same effect when I unscreww the cap from my much newer :-)
Jeep Grand Cherokee.

>                      and if it continues over a long period of time will
> collapse the fuel tank.  I know I had this problem.  

As I said, I notice no measurable flex in the sides of the tank.

>                                                     After I cleaned out the
> blocked restrictors in my fuel tank vent line I had no more vacuum build up.
> Cleaning out the restrictors is definintely a better solution than driving
> around with the fuel filler cap open.

With the better weather starting (I am considering taking the hardtop off
for the year this weekend!!) I will be able to start working on the car
somemore.  I will check out all the pipes and valves and see if I can find
any obstruction but I still think some small negative pressure is a result
of the smog control junk on federal cars.  It disipates quickly when the
car is not running and is noticed primarily when I race up to the pumps
and immediately pop the lid.

But all suggestions are appreciated and I can see where excessive vacuum
in the fuel tank could be a serious problem.

All the best.

bill

-- 
Bill Gunshannon          |  de-moc-ra-cy (di mok' ra see) n.  Three wolves
bill@cs.uofs.edu         |  and a sheep voting on what's for dinner.
University of Scranton   |
Scranton, Pennsylvania   |         #include <std.disclaimer.h>   


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