22-07-2019, 05:35 PM
One fault mechanism with these senders is the earthing of one end of the rheostat resistance wire to the body of the sender. This is achieved (at least in the example I have seen) by trapping the wire between a hole in the mazak body and the outside of the insulating tube through which the live connection passes. I suspect that the different metals set up a corrosion cell, and a poor high resistance connection eventually results. Dismantling, cleaning and reassembly is the cure. If you have an ohmmeter, the resistance of an original type sender should vary between about 2 ohms and 25 ohms as the float arm is moved over its range.
It's also worth checking that the fuel tank body is still well earthed to the car chassis/body, as it was originally on rubber mounts and u-bolts, which may or may not still offfer a good connection. The other connection is via the copper petrol pipe and thence via the fuel pump to the crankcase. Anything more than an ohm or two will upset operation.
It's also worth checking that the fuel tank body is still well earthed to the car chassis/body, as it was originally on rubber mounts and u-bolts, which may or may not still offfer a good connection. The other connection is via the copper petrol pipe and thence via the fuel pump to the crankcase. Anything more than an ohm or two will upset operation.