Rev 3 turbo bad fuel comsumption

[Mr2Madlad]

Hi all

I have a 1994 rev 3 Turbo which runs well.

Recently I have been really getting through petrol like 40 miles to 1/4 a tank drinking it.

There are no leaks in the fuel lines.

I've replaced the plugs, dizzy and arm, checked all hoses in vacuum no splits or leaks, also put on a new fuel filter as old one was 20 years old !

I have recently fitted a new Lambda sensor (due to drinking fuel issue) as the original one I found had open circuit heater (the lambda is a 4 wire 2 heater and 2 the zirconia sensor) this has made no difference in consumption.

All parts OEM Toyota.

took battery off and left off for a few days put back on taken for a drive, got it hot taken battery off again (while hot) reconnected and then driven it hard, made no difference.

No ECU error codes at all.

I do tend to run the car on the standard shell petrol and have owned the car for 10 years but over the last 6 months the consumption is crazy bad.

The only thing I notice is the car stick out a lot of soot and smells strongly of petrol again its not leaking any from lines or injector rail etc, so think its coming from the exhaust gas.

The engine is well maintained uses virtually no oil, has regular oil and filter changes every year (only covers 3000 miles in the summer as its my summer car) and compression test all 4 cylinders are pretty much identical.

Car has covered 98k miles, seems to run ok to me does 15 mile long drive Twice a day (weekdays to work and back) of which at least 12 is motorway and I have on purposely stuck to a decent speed to see if I can improve it but even at 55 - 60 5th gear mph its drinking it

Anyone know what is going on ?

[MR2 Rich]

I don't know if it would make much difference to fuel consumption but Mr2 turbo's need Vpower or Tesco 99 not your standard unleaded.

[CalMac]

Assuming you're going off the fuel warning light, that's 45 litres (55 litre is full capacity, 10L reserve) you're getting 16mpg. That's about what I get tbh with c.300hp, always short journeys and traffic (it may be the way I drive though )

Someone else may have some ideas but it sounds like you've covered all the basic steps to improve your consumption Is your turbo ok? Maybe check for play, as if the seals are gone then that would mean an inefficient turbo and black smoke.. Also, air filter? Maybe even try one of the engine de-gunking solutions?

[Shaoxter]

160 miles to the tank, that's not that bad... I normally get 150 to 200 miles.
But my driving is mainly city driving and hooning not cruising at 60mph

[bobhatton]

I do tend to run the car on the standard shell petrol

The engine is designed to use 100+ octane fuel found in Japan.
Even using the best fuel we have in the UK the engine is running under the control of the knock sensor. Once the ECU sees knock it will retard timing and richen up the mixture to save the engine.

Try some higher octane fuel for a time and see if it is any better.

[SonicSW20]

Have you actually measured the fuel consumption? The gauge is not accurate.

Fill it to the top, reset your mile counter (or begin logging journeys with your phone). Use at least half the tank (more the better), and fill it up to the top again. Note down how much you fill it with, and the miles you have covered. From there you can work out your MPG accurately. It's probably not as bad as you think.

[Mr2Madlad]

Hi

Turbo ok, not leaking oil, no blue smoke, spins fine and only very minor up down movement which the oil will take up when its running, no whine.

Oil like honey virtually clear so engine internals are very clean (did take sump off a while back due to leaking gasket and cleaned it up, not much waxy stuff in there at all at the time)

Used to get about 250 miles from a tank, I live pretty close to motorway so its motorway miles and I have been really efficient with my driving to see what I can achieve and its way down at the moment, some things wrong, very wrong, will get to the bottom of it.

I am looking to take out the injector rail and prime it to see if an injector is weeping / leaking under pressure (as exhaust stinks of petrol) at the weekend and maybe send the injectors to be ultrasonically cleaned as they have never been off in 22 years and most properly have varnish and crud build-up, would be good to know they are ok and giving a nice spray.

Gonna get timing checked once injectors are verified to be safe.

Air filter is a HKS mushroom and I clean it pretty much every week when in use.

Will update this weekend if I find leaking injector.

Thanks

[mr2garageswindon]

I'd be checking or replacing for the cost involved the coolant temp sensor. When they fail they don't put a warning light on as it is only measuring the coolant temp in order to put more fuel in when the engine coolant temp is cold. when they fail they usually allow the ecu to think the temp is cold all the time therefor over fueling. They are only about £20 from mr2 ben or anyone else. The gauge will show normal temp but the ecu reads from a different sensor ( the green one) Thats the first thing I'd look at when using more fuel than previously.
Jon.

[Mr2Madlad]

Hi all again

After a pain full half hour this evening I now have 4 injectors sitting on my coffee table to be sent for professional cleaning.

A trip to Toyota tomorrow to get a fresh set of rubber rings etc is on the cards as well, good job I have the GT86 ells I'll be car less (o:

No 2 injector was leaking quite a bit, (rail off but connected to petrol line and return, turned key to run fuel pump to pressurise) it was almost a constant stream, not sure if it was the injector internal valve or the rubber seal at the bottom of the fuel rail that seals the injector to the rail (as its a side feed in the rev 3) but that rubber was in about 8 bits when removed, the others are pretty shot too, gone rock hard and brittle.

Anyway injectors look pretty scumed up with a yellow type layer all over the ends that does come off with finger nail and black stuff too so think they deserve a clean.

Will upload a couple of photos when I figure out how to do that.

not too bad of a job, just getting the return pipe off the FPR was a pig as with that on the rail would not come past wiring loom, got it off (after a fight with the darn pile clip ahhh) and rail lifted right out.

Hopefully it will now be sorted, would advise anyone ells with similar age Mr T while working in / on this area to at least fit new rubber "O" rings while your there to save time and trouble later.

Cheers