Celsior seems to be using more fuel suddenly.....

[Robbos_Toyotas]

Hi Robbos

ECU Sensing not enough fuel? Is there a fuel pressure sensor on the 1uz, wouldn't think so, correct me if I'm wrong.
I too would like to know how a clogged fuel filter could cause more fuel being used.

mate i couldnt tell you to be honest...id have to go down and look at mine. I am not saying it "IS" the problem here but ive seen and experienced this before. Even my old ma70 7mge's fuel economy improved when i put a new fuel filter in. however id honestly like to know how it does make it use more....i only thought itd be electronic, hence i asked if hed run error codes...because error codes will normally eliminate a lot of things - codes tell you if ur o2 sensor is knackered....
Blake

[Z2TT]

Yeah,

After searching over the net I've found other people have had improved fuel economy after changing the fuel filter, but I don't understand, how?

["Z" UTE]

Z2TT, there is a very simple explanation for improved fuel economy after fitting a new filter.

The fuel pump located in the fuel tank has to push past dirty elements in the old filter, reducing in pressure as it does so. This reduced pressure has an adverse effect at the injector nozzles, in that the fuel does not atomize properly. When poorly atomised fuel is burnt, less energy is produced, than when properly atomised fuel is burnt.

So changing the filter restores the fuel pressure, the fuel atomizes properly, more readily releasing the fuels energy in the combustion process.

cheers Chuck.

[brett_celicacoupe]

Z2TT, there is a very simple explanation for improved fuel economy after fitting a new filter.

The fuel pump located in the fuel tank has to push past dirty elements in the old filter, reducing in pressure as it does so. This reduced pressure has an adverse effect at the injector nozzles, in that the fuel does not atomize properly. When poorly atomised fuel is burnt, less energy is produced, than when properly atomised fuel is burnt.

So changing the filter restores the fuel pressure, the fuel atomizes properly, more readily releasing the fuels energy in the combustion process.

cheers Chuck.

sorry im still not convinced

the fuel pressure regulates the pressure at it's piston. it doesnt care or know whats happening upstream. all it can do is regulate the pressure acting on it. it just keeps closing it's valve until adequate pressure is reached.

your saying the fuel pressure is regulated before the filter.




on this topic though, im about to drive my celsior about 3500km so im looking for some things to do to maximise fuel econ.

["Z" UTE]

Whoa, the fuel pressure regulator, is simply designed to bypass fuel, relieving excess pressure. If the fuel filter is restricting flow, and pressure, the fuel pressure regulator will not get a chance to do its thing.

cheers Chuck.

[Z2TT]

Good explanation, This could be why so many people have reported better fuel economy after changing fuel filters.

At $18, might aswell change mine.

[JoJo]

Ok, I finally got around to changing the ECU coolant temp sensor today.
When i went to take the old one out, it was already disintegrated. It came out in 2 pieces.
Anyway, I put in the new one, put it all back together, and now I am very happy.

It is amazing the difference it makes in performance, much more responsive and I got heaps of power back. And after a drive, it used about HALF (seriously) as much fuel as it would have before for the same distance.

thanks guys for steering me in the right direction

[Z2TT]

Ok, I finally got around to changing the ECU coolant temp sensor today.
When i went to take the old one out, it was already disintegrated. It came out in 2 pieces.
Anyway, I put in the new one, put it all back together, and now I am very happy.

It is amazing the difference it makes in performance, much more responsive and I got heaps of power back. And after a drive, it used about HALF (seriously) as much fuel as it would have before for the same distance.

thanks guys for steering me in the right direction

A++, Good job.

I assume that the engine was always running rich (even when hot) because of a bad coolant sensor?

[JoJo]

yeah, that was the case. Because the sensor was so brittle, I think it was already broken before I touched it. So, it wasn't actually working at all, fooling the computer into thinking it was always cold (ie; more fuel).

I don't know why Toyota didn't incorperate this into the diagnostic system. For one sensor to have such a huge impact on performance and fuel economy, you'd think they would have...

["Z" UTE]

Jo Jo, did you use a Toyota sensor, or aftermaket?, if aftermarket what brand and part number please. My spare 1UZ is minus the same sensor.

cheers Chuck.

[JoJo]

Chuck, It's an aftermarket sensor.
It's a Tridon sensor, part # TCS-032. Repco $79, supercheap $43 and autopro $54. They can all get them for you but they have to order them in. But Tuggeranong Autopro had one (maybe have more) in stock so I just got that.

regards,
JoJo

[AndyTTR]

Great to see you got it sorted! Changed my one last week, it was pretty brittle but not snapped like yours!

I bought a genuine Toyota one, cost $65 iirc. p/n 89422-20010

[Z2TT]

I should test mine, what voltages should I get when cold and fully warm?
Same for all toyotas?

[JoJo]

Is this what your after?

[Z2TT]

Thanks, so I assume 90c Should be what it is when it's warm. So should be about 0.2 to 0.3 Kiloohms.