Noisy fuel pump (still!) (and again!)

["Walter Coe" <Whalt@xxxx>]

I'm still trying to find out how to keep my fuel pump quiet after it gets
hot. Here is what I have done so far:

Replaced fuel pump: still noisy.
Replaced fuel suction line with PJ Grady's & installed make-shift NAPA fuel
suction screen: still noisy.

I figured that maybe my problem was from the new fuel suction line
collapsing or from the cross-reference fuel suction screen. I installed a
screen-door spring in the fuel suction hose and modified the fuel suction
screen. Since I have heard noisy fuel pumps on other DeLoreans with the OEM
fuel suction screens, I figured maybe they were too restrictive. The NAPA
STS-36 when new is less restrictive, but it is not made to rest on the
bottom of the tank where it will eventually collapse & restrict the inlet
under it's own weight. So I got a short piece of the left over screen door
spring and put it inside the fuel suction screen. I did this by cutting the
bag open, putting the spring in and then 'welding' the end closed with
JB-Weld (oh I just love that stuff! :-) I am satisfied that this monkey-rig
fuel suction screen is now 'custom high performance' compared to OEM.

And the pump still makes noise when the fuel gets hot!

I pulled the fuel sender and stuck a thermometer in there. It read 118
degrees F! Can you believe the fuel got that hot with about an hour's
driving? I think that the upper limit for household hot water heaters is
120 degrees F, and even that will scald people. I do not think it is a good
thing for the fuel to be this hot even if it didn't make the pump noisy.

I measured the level of the fuel with a stick & found that there was 7cm of
fuel left. I got a mechanic's mirror & flashlight (one that won't ignite
fuel vapors) and looked inside the tank through the fuel sender hole. It
was hard to see in there, but I could tell that everything was in place and
not kinked. The fuel level was still high enough to cover the bottom of the
pump.

Now I am on a mission to find a way to keep the fuel cooler. This is not so
much just to keep the pump quiet but also I think it will make the fuel
system components last longer. Many people have recommended installing an
air dam between the tank & the fans. Can anyone supply photos or
dimensional drawings for this? An idea I just came up with today is
replacing the aluminum pipes running on either side of the fuel tank using
long pieces of silicone hose. This will insulate better than aluminum. I
am also planning on installing a fuel line cooler. There is one in the
SummitRacing catalogue as part # FLX-4136. It doesn't give any pressure
ratings, but if installed in the return line, pressure rating isn't much of
a concern. Can anyone say what it will take to match up -6 AN fittings to
the DeLorean fuel system? Can anyone suggest other kinds of fuel coolers?

Walt Tampa, FL 03633 lic. WATSDAT