Revvies

Hi all!
I recently bought a '65 Mustang Convertible that had gone through a light restomod and now has a 302 5.0L from a '89 Mustang (it originally had a 6 cylinder). Overall the swap/upgrade is very nice, but I have noticed that the fuel gauge doesn't read correctly. For instance, when the tank is full the gauge only reads 3/4 of a tank.

My question:
Do I need to replace the fuel sending unit in order to get an accurate reading for a '89 302?

If so, can you provide any guidance on WHICH fuel sending unit I need? I've looked on NPD and CJPonyParts and found at least 4 different options for "V8s" in 1965.

Thanks

Starfury

The motor doesn't affect the fuel gauge reading.

Before replacing the sending unit, I'd clean all of the contacts at the gauge and at the sending unit and apply some dielectric grease. Could just be a bad contact.

I believe there are resistance measurements posted somewhere (you might have to dig through some forum history), and it would be easy enough to check resistance measurements at the gauge contacts and at the sending unit itself. If resistance at the sending unit doesn't match up, you know where your problem is.


This is the sending unit I would expect to find in your car. There are also 3/8" outlet options, but I would only recommend that if you also plan on replacing the supply line from the tank to the pump.

Revvies

Perfect! Thanks

Starfury

Good luck! Let us know what you come up with.

zeddy

Crawl under the car and pull the wire off the sender. Clean it and short it to ground. Start the car and it should read full. If it does then your problem is in the tank. If it doesn't then I would look at the regulator on the back of your gauges or it's your fuel gauge itself.

zeddy

One more thing. If it shows that the problem is in the tank. Pull the sender and check the float. It may be saturated or if its brass, it may have a crack in it-mine did.