[manuotieno]

I have a Toyota Raum with a 1500cc engine, auto transmission and 4 wheel drive. Proble is the fuel consumption... on average, urban running returns roughly 10.6 kilometers per litre. On the highway I get around 13 km per litre.
Am concerned with the consumption as it is way too high. I have changed the ignition lead wires (on the dealer's advice) and still no change. Now the same dealer is saying it may be the valve seals or de-cork gasket (whatever that is):mad: . I don't intend to pay for guesswork. Anyone out there have any clues that may be of help?:confused:

[CaptainRich]

Worn valve seals will increase oil consumption and create oil smoke when accelerating from a stop. But they will have little to do with fuel economy!
"de-cork gasket"? I need a translator for this item!

Generally speaking, how is the engine running? Have you had the fuel system treated professionaly? i.e.: proper cleaning (as in: not the useless crap that you can add to the tank)

What climate are you operating in? Colder climates will require more fuel to run with colder air.

[manuotieno]

Thanks for the response CaptainRich.

I concur with your sentiments about worn valve seals. I also did not understand how they would affect fuel consumption.

Generally speaking, the engine sounds OK, there is no smoke emitted when accelerating from a stop. However, there is some carbon residue on the exhaust pipe and I find this to be of some concern considering that the car has EFI.

As for treatment of the fuel system, apart from adding Wynns 3XA into the tank after every service, I have no clue of what this treatment entails. Would you please advice?

I operate in a tropical atmosphere (Kenya), which is generally warm at this time of the year... in fact it gets pretty hot!

On inspecting the ignition leads, I also found that the hard plastic casing that guides the lead into the spark plug well is cracked, though the insulation cover on the actual lead cable inside it is intact. Could this be the cause?

[CaptainRich]

However, there is some carbon residue on the exhaust pipe and I find this to be of some concern considering that the car has EFI.

The carbon deposits are likely due to excessively rich running. There's bound to be some but it should not be too heavy.

As for treatment of the fuel system, apart from adding Wynns 3XA into the tank after every service, I have no clue of what this treatment entails. Would you please advice?

Typically, a professional cleaning would require disabling the fuel pump and running a quality can of pressurized cleaner through the fuel injectors. The stuff that goes into the tank can help reduce the build-up of varnish that accumulates inside the injectors after the injectors are fully cleaned. If the can in the tank was strong enough to actually clean the injectors, it would be too harsh for many fuel system components.

On inspecting the ignition leads, I also found that the hard plastic casing that guides the lead into the spark plug well is cracked, though the insulation cover on the actual lead cable inside it is intact. Could this be the cause?

Unless that cracking leads to a misfire, I would think it's only cosmetic. The key here is finding why your using too much fuel. How long has this been going on? Is it a new condition or is it gradually getting worse?

[manuotieno]

The carbon deposits are not too heavy. I just get concerned when I compare with other similar cars and see that whereas my exhaust tip has a dark colour, the other cars have a brownish hue.

I have not yet heard of anyone who cleans the fuel system as you describe. Will have to keep a lookout for that.

The fuel consumption has been high ever since I imported the car (used) from Japan. It has not been getting worse. It remains constant.
However, this week I have been experimenting with changing my driving style by less use of a lead foot and it seems to have made quite a difference. I suspect this has been the cause:o . Got to learn to drive it like the mini minivan it is rather than driving it like a sports car.

Will let you know how this turns out. :)

[manafrica]

Am having the same problem with my raum year 2004... consumes 1 litre per 8kms... crazy I think there is something wrong with raums...