2 issues - carb and fuel gauge

[davidmij]

Hi all,
I need to order two idle mixture adjustment needles for my Autolite 4100, but NAPA doesn't have a listing for my FoMoCo tag number C5AF F. The carb is the same as the stock one from my original 1959 352 car. Ford (autolite) made a 1.12 venturi and a 1.08 venturi. I have the 1.12 on a 390 motor.

Second question; Per the troubleshooting guide in my 1959 T-bird shop manual I found that my gas tank sending unit was bad. I bought a new and replaced it. My gauge now works but the needle fluctuates slowly between 1/4 full and 3/4 full. When I start the car it reads approximately correct at 3/4 full, then as I drive down a flat road it eventually went down to about 1/4. Can anyone tell me what might cause this?

thx as always, Dave J

[simplyconnected]

...My gauge now works but the needle fluctuates slowly between 1/4 full and 3/4 full. When I start the car it reads approximately correct at 3/4 full, then as I drive down a flat road it eventually went down to about 1/4. Can anyone tell me what might cause this?..

As the Instrument Voltage Regulator ages it also tends to become erratic. OEM regulators work just like turn signal units, by heating a bi-meta strip. This is an inexpensive method for averaging 6 volts.

You need to buy one of my solid state Voltage Regulators. Shoot me a PM and we'll arrange it. - Dave

[KULTULZ]

I need to order two idle mixture adjustment needles for my Autolite 4100, but NAPA doesn't have a listing for my FoMoCo tag number C5AF F. The carb is the same as the stock one from my original 1959 352 car. Ford (autolite) made a 1.12 venturi and a 1.08 venturi. I have the 1.12 on a 390 motor.

Dave J

The FORD P&A Number is- C8AZ 9541-C (CM-722) if that helps.