QuestionQUESTION: Can I use a NOS AZX1318 Pos. Ground fuel pump to replace an AZX1307 Neg.
fuel pump for my 1970 E-type?
This car is a U.S. Spec car for emissions (originally). There is a wedged
shaped tank that looks like a vapor recovery tank that I think was removed
from the area of the Fuel pump behind the rear wheel well. It has tube
connections on it but the hoses were cut off. Does this belong with the car?
It is possible that it was just thrown in with loose parts. The tank is about 10
inches long, 3" thick at the wide end and wedge down to 1" thick at the other
end. It is about 8" wide. It also has 4 -3/16" tube barbs sticking out of the
wide end. Any ideas?
ANSWER: Sorry Karl, I don't remember any such can in the fuel system on any of the "E" types. Unless it a vapor separator for the vent system but I don't ever remember seeing any such can.
Howard
---------- FOLLOW-UP ----------
QUESTION: Thanks for the reply, the followup would be- do the vent tubes on the SU fuel
pump need to be plumbed to the exterior, or are they just for dust control?
Also, I have available a AZX1318 fuel pump which is a Positive ground version of
the AZX1307 Negative ground pump supplied on this vehicle. Will this work by
reversing the leads, or is there something else to consider?
AnswerI am not failure with the pump numbers so that don't do anything for me. Are these the in-tank rotary pumps? Most SUs I seen had only one insulated pin on the end of the pump and a ground lead on the base and these could not have the leads reversed because the base would be grounded and it would short out your power supply however, if both the (+) and the (-) connections on the pump are mounted in insulation (plastic) do this,
With the two pumps on the bench take the (-) ground pump and a 12v battery and connect the (-) test lead to the (-) pin on the pump and touch the (+) pin with the (+) test lead and note the direction the pump turns.
Now take the other pump (+ ground pump) and connect the (+) test lead to the (-) pin (only if it is insulated) and only touch the negative test lead to the (+) pin to see what happens. If it is an in-tank pump and it runs, note the direction it rotates. This is important as most all permanent magnet motors will reverse direction when the polarity is reversed. If, when you connect up the test leads it does run, all you need to do is reverse the leads.
If the (+) pin on this pump is on the base of the pump plate and not insulated then even though on the bench it ran ok and in the correct direction you can not use it as it is. You would need to reverse the leads on the motor itself inside between the motor and the outside connections. Because as soon as you connect the power supply to the base connection you will blow a fuse or burn a wire.
Some external SU pumps had diodes in them and that prevented a reverse connection being used but I don't know if that was done on any internal pump.
Let me know,
Howard
