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

[Robbos_Toyotas]

blocked fuel filter does cause this problem. i dont know how it does it - whether it dicks with the ecu/ fpr etc?

[Z2TT]

I'd think if it was blocked the car would run very rich and use less fuel.

[JoJo]

I'd think if it was blocked the car would run very rich and use less fuel.

Hey man,
can you explain this theory better. To me, that just makes no sense......

Thanks,
J

[brett_celicacoupe]

in regards to some of the suggestions.... i think you need to evaluate how they fail/wear/age in terms of performance. i personally hate replacing shit blindly until there is an result.

ie fuel filter becomes a restriction in the worst case - outcome is that the pump steps up the pressure to maintain the same rail pressure. i dont see this being a problem. the FPR doesnt care whats happening upstream, it just regulates the pressure right at it's seat.

also you would expect to feel if something was affected on one cylinder only (ie injector/spark plug) which means its unlikely that all 8 would go at once)


you can sort of test the o2 sensors by putting a wideband in the tailpipe and watching it while cruising. usually they cycle around the stoich mark.. going under and over by a little bit. personally i would be leaning towards these.

[Z2TT]

Sorry mistake. I meant to say, if the fuel filter were blocked, wouldn't the car run very LEAN and use less fuel.

["Z" UTE]

JoJo, the problem started after the radiator change, the, I would suspect that the the guys who did the radiator change may not have bled the coolant system properly. The ECU water temp sensor is probably sitting in a bubble of air, and will not be sensing true water temp, consequently your engine will be running on cold map.

cheers Chuck.

[Z2TT]

Could well be to do with the temp sensor.

[JoJo]

JoJo, the problem started after the radiator change, the, I would suspect that the the guys who did the radiator change may not have bled the coolant system properly. The ECU water temp sensor is probably sitting in a bubble of air, and will not be sensing true water temp, consequently your engine will be running on cold map.

cheers Chuck.

Sounds like that could be right chuck, as Iam pretty sure it did start around the time of the radiator change. I have been away, but the temp sensor will be the first thing i check....

Thanks Chuck,

JoJo

[Robbos_Toyotas]

isnt the fuel filter a cheap experiment to see if it fixes it? the oxy sensor id think would only make it use more fuel when its cruising on hwy for example, as my 7mge supra did this, but i only noticed it using more fuel on hwy, the new sensor made no difference whatsoever around town, only on hwy trips. i really cant see it being anything else. Worst case scenario you replace the filter, which should be done every 50k? anyway....and hope it fixes it.

[JoJo]

isnt the fuel filter a cheap experiment to see if it fixes it? the oxy sensor id think would only make it use more fuel when its cruising on hwy for example, as my 7mge supra did this, but i only noticed it using more fuel on hwy, the new sensor made no difference whatsoever around town, only on hwy trips. i really cant see it being anything else. Worst case scenario you replace the filter, which should be done every 50k? anyway....and hope it fixes it.

Please explain why the fuel filter might make it use MORE fuel?

[pato]

o2 sensor adjusts af on cruise to give stoich and therefore increased fuel ecconomy,
by unplugging the o2 sensor (if its working that is) and driving around, essentially u would notice no difference to performance and drivablilty, u would only notice a substantial lightening of the wallet as the fuel burns like nothing else.

hence why, if the o2 sensor has gone pop, this explains your car symptoms.

i also believe that the coolant temp sensor could be playing up as well, especially if u have been having problems since having the radiator replaced ( in where the temp sensor is sometimes located, not sure about celsior tho )

[Robbos_Toyotas]

Please explain why the fuel filter might make it use MORE fuel?

mate to be completely honest i have no idea how it does it, but it does. for example, bosses bt50 was only getting 400km per tank of juice - my v6 hilux was more economical! he had the fuel filter changed (which mechanic told him was blocked) as they could find nothing wrong with the car - its only done 40,000km....now he gets around 500-550 a tank fully loaded up.
my old amg was pretty much the same....
obviously the filter wont be completely blocked, otherwise the car wouldnt run! but it definetly does make a diff.
anyway good luck with it.

[JoJo]

mate to be completely honest i have no idea how it does it, but it does. for example, bosses bt50 was only getting 400km per tank of juice - my v6 hilux was more economical! he had the fuel filter changed (which mechanic told him was blocked) as they could find nothing wrong with the car - its only done 40,000km....now he gets around 500-550 a tank fully loaded up.
my old amg was pretty much the same....
obviously the filter wont be completely blocked, otherwise the car wouldnt run! but it definetly does make a diff.
anyway good luck with it.

But wether the pump is pumping more fuel to get through, surely the fuel pressure reg would be the same pressure at the engine

[Robbos_Toyotas]

yes but the ecu may be sensing there is insufficient flow/ pressure and hence might be pushing more through the injectors to compensate to save it leaning out/?? have you run any error codes on it??

[Z2TT]

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.