Fuel gauge reading Gas level when starting on Petrol

[LANKY 1]

When ever i start the ute (on petrol) it shows me the gas fuel level, and then slowly the gauge needle moves up (or down) to read the fuel level after 15-30 mins.

Shows gas level alright when starting on gas.
It never used to do this.

The gas system uses the standard fuel gauge in the dash. So swapping between the 2 fuels on the go takes a little to give the real level.

[Mr Hardware]

factory dual fuel?
mine switches instantly

[LANKY 1]

I think it was put on after the ute had been bought but pretty soon after

[AMB]

They take along to to react because of the buffering Lanky, but yours seems to have developed a wiring problem/short -if you are running on petrol, the lpg should be switched off -maybe its a problem with the relay that switches the fuel gauge between petrol/lpg. Mine does the opposite - it starts on petrol and switches to gas, so it gives accurate petrol reading instantly, then takes a long time to adjust to give the proper lpg reading. I can remember reading in the lpg forum, that you can add a diode somewhere to stop the problem, but they gave no details.

[LANKY 1]

Yeah i figured the buffering would be why it takes a while to change. might try and have a decent look at the wiring.

[AMB]

You said it never to used to do this, so I would think the first thing to check is the fuel gauge petrol/lpg relay. They sometimes cut into the petrol tank sender wire inside the kickboard next to your right foot. Trace that wire and you should find the correct 2-way relay. I think the way it works is that when the relay is not powered, it conducts the petrol sender, when it is powered it conducts the lpg sender.

[LANKY 1]

i'll have a look there too.