Re: Intermittent Flash Fuel Pressure Light 74 Spider

["Dean W. Cains" <dwc@xxxxxx>]

Hi Jon:

You have a couple of options to try here.  The first thing one should 
usually look at is the rear fuel filter; the one that hangs between the 
fuel tank and the fuel pump.  They're around $15, so that's the least 
inexpensive thing to try, and might need changing anyway.  A car that old 
is bound to have some amount of crud and rust in the tank, and the filter 
clogs easily.  There is a Purolator filter that I like to use, which is 
#F33165.  It's larger than the original filter, so you need to expand the 
clamp that holds it in place, and replace the rusted old bolt with a wire 
tie to hold it in place.  You many also have to change the two short fuel 
hoses that connect the filter to the pump and the fuel tank.  Since there 
is no telling what fuel pump you've got, I can't tell you exactly what size 
hoses to use.  I think I used 3/8" inside diameter (or maybe 7/16"), but 
I'm not sure.  You may have to stretch the hose over either the tank 
fitting or the pump fitting, as they're not all that same size, but it's no 
big deal.  Buy hose that fits the smallest fittings correctly, and stretch 
it over the larger ones.  The OEM filters haven't been available for a 
while, and if you order one from Centerline or IAP, etc, you'll have to do 
the same thing with regards to the hoses, and I like the Purolator because 
it's got much more filter media.  Since the fuel flows by gravity from the 
tank into the filter, make sure the fuel tank is nearly empty, but you're 
still going to spill some fuel, so take precautions.  If you're feeling 
ambitious, change all the hoses in the system, upstream of the fuel pump, 
which I believe are all 5/16" I.D.  Some may be collapsed internally, which 
won't help your fuel pressure.  It's a small job, and again, just costs a 
few $ for the hoses and some new clamps.

If that doesn't fix the flickering light, it can be several other 
things.  Many times the pump pressure isn't high enough because the pump 
isn't getting enough voltage.  The original wire is just barely large 
enough, and now it's got all those years of corrosion and degradation, 
too.  Check voltage at the pump, with the car running, if you can.  You 
want to be as close to 13 volts as you can.  Compare the voltage at the 
pump to the voltage across the fuel pump fuse up front.  Clean all the 
terminals, clean all the grounds, clean the fuse and holder.

The problem might also be that the pressure sender, located in the fuel 
filter housing on the right front inner fender, may be failing.  They're 
also around $15 to replace, so again, not a big expense to try.  The filter 
in that canister may be clogged, but it's much less likely for that one to 
get clogged than the filter under the fuel tank.

Finally, there's the fuel pump.  If nothing else works, then that's about 
all you can replace.  Vick Autosports sells the later-style rebuilt Bosch 
pumps for a reasonable amount (~$150?), so don't get suckered into paying 
$450 for the "original" pump.  On my '74 I bought a Master E2000 pump (Ford 
F150 application) that meets specs and works great.  It was ~$75 at 
AutoZone, and has a lifetime replacement warranty.  A few years ago I 
posted this info to the Digest, and got all sorts of hate mail, but I 
haven't had any problems in those 2 years.  I won't guarantee all these 
generic-type replacement pumps are all the same, and/or that they'll all 
work, but obviously mine does.  It looks like a clone of the late-style 
Bosch pumps, too.

Let me know if you need any more help.

Regards,

Dean

At 10:01 AM 3/28/2003, you wrote:
>The fuel pressure light blinks after warming to about 150 degrees. 
>However, there is no noticable performance issue. The light will not come 
>on for about a minue if I shut down the car and restart.
--
to be removed from alfa, see /bin/digest-subs.cgi
or email "unsubscribe alfa" to majordomo@domain.elided