my mate has recently rebuilt his engine after it spun a big end, everything is sweet but at about 2000 revs it hesitates very slightly then when comes on boost makes a trumpet sound and loses power, theres no fault codes coming up and we've checked for leaks ect. its got lightened flywheel, pulley set, full exhaust and prodrive ecu. any ideas???????

 

Plugs, plug leads to eliminate first.
Trumpet noise could be anythingair or turbo related, connections to intercooler etc.

 

we've done plugs and leads and coil pack checked all boost pipes for leaks etc.

 

Short of driving the car and experiencing it I don't know what it might be.
Where are you located?

 

Trumpet noise could also be attributed to all the Xmas dinners???

 

located in lincoln mate.

 

So I guess you are 90 odd miles from me and I don't know anybody in Lincoln I can recommend you to. It really needs somebody that knows what they are doing to drive your car.

 

its not my car its my mates, mines still in bits in garage lol. i think he gona borrow a coil pack to try to eliminate that and go from there.

 

We had a guy here from Doncaster yesterday for a set of plugs and map adjustment. Plugs did not cure the missfire and we ended up fitting a new set of leads and coil pack.
V5 M/Y 99 car so around 12 years old.
The owner commented on how smooth and willing the car was and it did feel transformed to me. I think his coil pack was showing its age and was pretty weak and under load two of the plug leads were arcing.
Do not fit aftermarket plug leads. Stick with the Subaru items.