Poor Fuel Consumption

[Rob Clack]

After I had my Avensis T-Spirit serviced, I found my fuel consumption was very much worse. Normally, I'd expect to get about 500 miles on a tankful, but last Saturday I'd only done 400 miles when I had to refill. I'd also noticed that the engine sounded louder than before, what my wife called 'rortier', and that it was harder to start. The engine would fire, then die, and could take several attempts, even when hot. I took it back to the service station and they found that the air filter cover had not been properly refitted.

Now on a petrol engine with a carburettor, I could see how the poorly-fitted air filter cover might cause those symptoms, but I'm not familiar enough with fuel injected diesel engines to know whether that would be enough to cause my fuel consumption to worsen by 20%. Can anyone advise me?

[Fluffmeister]

Where is the MAF on the 2.2's?

On Vag cars I have seen similar in the past when people had removed the airbox cover or debaffeld the airbox on certain PD130 models. It could be that if the MAF (MAss Airflow Meter) is confused into thinking that it's colder than it really is, it could cause more fuel to be injected and worsen consumption. It could be that the MAF is dirty and again supplying the ECU with incorrect measurements, and the ECU dumps in more fuel.

That was a problem you could see realtivley often on some VAG cars.

You could disconnect the MAF and see if fuel consumption is still pants on a short run, there is a decent video explaining how it works here

There could be many other factors, but if it's an airbox cover, and maybe the filter got dislodged I would put money on the MAF.

Cheers

Fluff'

PS, Welcome to the forums.