Temp and fuel gauge annoyance

[80s-new-man]

I’ve a new fuel gauge in 2020 that never seemed right on the gauge, reading far too high.
On a recent long journey to beaulieu I noticed the fuel needle went up then down then up again in constant straight traffic. Weird.

I’ve changed the temp sensor a few times now. I’m sick of it always reading so low it hardly gets off the bottom.
I measured voltage at loom and at sensor to block when hot. 4.6 volts at all locations.
I’ve swapped temp sensor again and yes I’ve tried white ringed and a new one from car parts in motion, which they say is a 2.8 version . I’m tired of keep changing them.

I’m just wondering - are these symptoms of fuel and temp behaviours the result of a possible faulty voltage regulator?
If so, can they still be bought?

Help most appreciated!
Cheers

[Mc Tool]

I would be lookin at the reg . I think they are supposed to regulate instrument voltage to a bit over 5v. Dunno if you can still get them new but a 5v dc reg is not that hard to come by .

[nemo]

You need to check the voltage on the lead when it`s disconnected from the sender (temp), If that`s showing about 5v the regulator`s probably OK, it may well be that the connections to the regulator on the PCB need cleaning? Making & breaking due to vibrations while moving?