ian10

my car has a hesitation at around or up 2500rpm then it's ok.
i've changed the maf and lambda sensor.
anyone got a clue what this could be,
could this be something to do with close loop/open loop fueling ?
thanks..............

dynamix

iTrader: (3)

Have you got a VTA dump valve on it?

If so, swap back to the original dump valve.

When did the hesitations start?

Any info on your car/mods would really help....

ogo

My 2001 runs rough/hesitates at around 2500 as well. Its got a Prodrive pack fitted. Power comes in all of a sudden as well at around 4500. I am not sure if its all ok. I would prefer a more linear power delivery.

BlooSooby

I've just had a new EJ257 short block rebuild and I'm suffering the same problem. I get hesitation between 2000 and 3000rpm but all is good once on boost.

We've changed both the lambda sensors, the MAF sensor and the MAP sensor as well as the injectors but it still does it.

I've run out of ideas other than poor mapping but any mention of poor mapping are met with derision from the builder as he thinks the ECUtek mapper is completely infallible.

dynamix

iTrader: (3)

Hi Bloo - we have spoken before on this about the hesitation on your car and you were going to get it checked.