v6 power fade

[stresshead]

i have an annoying power fade on a vectra gsi v6.
when cold the engine produces oodles of power right through the rev range, but when its hot the power seems to dip at around 2500 rpm and kicks in again at around 3000rpm. this is quite a recent developement. has anyone got any ideas as to what is causing this anomoly?.

[danhay]

I had a similar problem on a Cavalier V6 that I had. It turned out that a plastic part of the induction system had split and was leaking air in downstream of the airflow sensor. The result was that it was running lean. When it's cold, there's extra fuel put in so it wasn't a problem until it got warm.

So check your induction system for loose fitting parts or cracks?

The other alternative is that a sensor in the Fuel Injection system is faulty and that could be a lot harder to trace?

[pdV6]

danhay said:

a plastic part of the induction system had split and was leaking air in downstream of the airflow sensor. The result was that it was running lean. When it's cold, there's extra fuel put in so it wasn't a problem until it got warm.

Could also be the airflow meter itself