If it's just the gauge jumping and there is no actual increase in RPM, then the gauge or the pickup is faulty. If the RPM is actually climbing as you drive, your transmission could be gearing down or your transmission is slipping under load, automatic or standard.
you need a dial gauge which screws into the back of the pump its pretty simple after that.
Thermostat may not be opening
A bad fuel sending unit, a fault in the circuitry for the fuel sending unit, or possibly a faulty gauge.
where is fuel gauge and how to replaced for a 1986 Mazda pick up B2000 please let me know thank you
why would a speedometer stop working on a Mazda
In the fuel tank.
A common problem with Honda cars is that the fuel gauge is stuck on full. This problem is solved by replacing the gauge cluster.
you need to replace the gas gauge sending unit in the tank, or your gauge is broken
No.
my gas gauge is not working what could be the problem
It really depends which sort of GAUGE you have. For example; you couldn't wire a volt meter to the oil pressure switch.
there is a problem with the thermostat. it needs to be replaced.