DeTomaso Mailing List: October 2000, Message #116

You are very close in your assesment of the fuel line problem.  I have a 74
and it uses the pickup on the fuel guage stem.  But the tank still has the
early style pickup tube.  I tried to use this line as a return for my efi
and noticed that when I put fuel into this line, it squirted out
everywhere.  What I found was that this tube is not solid steel tube but a
rolled and welded tube of low quality.  Seems that the tube had split at
the weld and was leaking fuel.  Now if you used this tube for a suction
like all you would get was air.  This very well could be your problem.
Perhaps that is why they went to a different fuel pickup.

Now my interpertation on the pickup sock.  It is not there as a filter, it
is used to prevent a large object from being sucked into the tube thus
plugging it up.  By having the sock around the tube it cannot be pluged
under normal situations.  Also note that many cars come with a removable
sock on the pickup that could be used in the pantera.  On car that comes to
mind is older 70s cadillacs.  I assume all gm cars of that era were the same.

Dave "fuel guy" D

At 08:35 AM 9/30/00 -0400, you wrote:
>All the other list suggestions are good ones.  They are similar to the
ones I 
>got six months ago for a similar set of symptoms.  I did all the same
stuff - 
>replaced the fuel pump, installed a mondo inline filter, replaced the two
line 
>filters at the carb I didn't even know I had (which temporarily fixed it but 
>then it came back), pulled the tank filler and gauge sending unit off and 
>looked into the tank with a flashlight through the quarter window (no sock
at 
>all), blew air down the feed line in the tank ((which is welded in and not 
>removable on my car).  Nothing really worked.
>
>Then I ran a line off the bottom of the tank by drilling and tapping the
drain 
>plug with a pipe thread elbow.  No more problems.  Hmmm.  Sounds like the
tank 
>line after all.  My theory is that there were some pinholes in the gas tank 
>line but generally the pump could suck faster than the pinholes could leak. 
> When things really got warmed up though, like after a short shut down heat 
>soak or driving in traffic, enough pressure would leak off that the car
would 
>vapor lock.  Then I got to sit on the side of the road in my shiny red hot
rod 
>and wave at all the 73 Buicks that passed by trailing smoke and other debris 
>but which were still actually running.  This happened more than once by the 
>way.
>
>But the elbow on the bottom of the tank was too scarey for me.  As Jack
DeRyke 
>indicated, it is exposed to road debris and if the fitting snaps off, say
in an 
>accident or from sliding off the pavement at the track, then gravity will
drain 
>your tank for you - possibly all over your red hot exhaust.
>
>Then somebody on the list told me about Ron Siple.  He was able to tap my 
>sending unit for a new tank feeder line.  Ron did a great job and every
thing 
>fit perfectly.  Now I have a larger line that can deliver more fuel and  I
can 
>use the old perforated feed line as a return line for the EFI setup down the 
>road (yeh, right).
>
>I hope the easy stuff fixes your car but if not keep Ron's solution in mind.
>
>Dave
>
>
>
>