Fuel Light On

[KJS]

Hi all, I have 3 questions:

My Fuel Light is constantly on ever since I replaced the LED bulb. (since 2wks ago)

Before the replacement, I never see the Fuel Light on even when I am left with half bar.

The 5-SMD LED bulb is said to be suitable for "T10 194 168 W5W 5050"

I am wondering, is there something wrong with the LED 5-SMD bulb?

or something wrong with my Fuel System? (Fuel Injectors, Fuel Filter, Fuel Pump etc)

or something wrong with the original light bulb -_-

My idling is a little rough recently. (since 3wks ago)

If you can see from the photo, the idling is about 100rpm more than usual 600rpm.

Sometimes I notice rpm needle has very slight fluctuation, but sometimes it just sits there.

It used to be steady 600rpm at idling.

Would this be a vacuum leak or boost leak? (sorry, i don't have a gauge)

I get 305kms before reaching half bar of fuel (but every morning I need to endure 8kms of traffic congestion on the way to work)

My oil pressure, is it a little low? (about 2months)

It has been like this for a while.

I have changed oil and oil filter recently.

The vehicle is an 1993 RB25DET Automatic stock.

I am not very good at car.

[SargeRX8]

Oil pressure seems low. Could be a bad reading. What I'd suggest is try a thicker oil. The rpm hunts because of many reasons but more commonly vacuum leaks or a dirty aac valve. There is a guide here on cleaning the aac.

Try change the led back to the normal bulb and see if the light turns off. If it stays on then the fuel level sender might be stuck. You could get your hands in the tank and see if its stuck or try bash it from the outside.

305km to half a tank is amazing. I get almost that from full tank.

[Ben C34]

the level sender is separate to the low fuel light. so if the level sensor is stuck it wouldn't effect the light. the light is controlled by its own sensor in the fuel tank. check wiring for that.

[Ben C34]

low fuel light sensor circled.

[SargeRX8]

Good to know. Would have thought the sensor would have been used rather than two independent components.

[89CAL]

I think the sensor works off resistance yes? My fuel light comes on gradually when it gets low.

Im wondering if this is the case, and because LED's draw much less current then normal lights, it may cause it ti stay on. Switch back to a halogen (swap from one of the others if you need to and if that fixes it I dare say you just wont be able to use an LED

[KJS]

Thanks for the replies.

I switched the LED back to Halogen and the light just went off.

Took me a while to locate where I kept the original halogen.

This is rather strange, the LED lights up but is not suitable to be used

So normally it would be nearly 100kms when finishing first bar of fuel

Now only 60kms.. and idling sits higher.

When car is in D and stationary, the rpm sits at 700rpm (used to be 600rpm)

When car is in P and stationary, the rpm will hunt a little.

The oil I use is Penrite 10W-40.

Edited June 12, 2013 by KJS

[GTSBoy]

Have you tried putting 12v on the old dash globe direct to see if it even works? The reason it is off now may be that it can't turn on. In which case the LED wouldn't have been the problem, just revealing the old problem.

As to the problem with idle speed and fuel consumption.....I often find that I use more fuel in cold weather and the ECU keeps the idle speed higher too. So there may be nothing wrong. But, the things to check are 1) the coolant temp sensor, 2) the state of the AFM sensing element, and 3) whether the oxy sensor is working. These are the 3 usual suspects for high fuel consumption.

[SargeRX8]

Yeah you've gotta double check that the globe is working properly. Swap the halogen globe with say the handbrake globe and pull the brake up and ensure the light turns on.