Not Hitting Target Boost on EVO 4.

[TIM EVOIV]

Hi guys,

Having to begin looking at why this EVO 4 will no longer hit target boost.

Stock TurboCharger
Apexi Power FC (mapped by DP)
Apexi AVC-R
EVO 7 Injectors.
Walbro 255lphr Pump.
Aftermarket Actuator (Recently fitted)

The car was previously mapped to Mode A: 1.0bar , Mode B: 1.25bar.

The week or so after mapping, Mode B received overboost spikes of up to 1.33bar.

Now we can't get the car to boost past 1.16bar no matter what we do with fiddling with the AVC-R....Set even to 1.30Bar, Duty at 90%.
(F/B set at 3 throughout - not been changed since 1.33bar experience, rpm based boost/duty settings not active - same across the range)

The Actuator was previously replaced (before mapping etc) so is persumed to be working correctly

We've looked for possible vac leaks, reset the boost pipe connections and looked for boost leaks from I/C, nothing seems to be leaking.

It'll hit 1.0bar quite quickly and hold it on Setting A....but it won't boost past 1.16bar.

No Smoke from turbo...

Any ideas??

Have checked the Pressure Sensor for the AVC-R...
Will replace the vaccuum lines for the Actuator and Compressor Outlet to the AVC-R Solenoid soon...
And will strip down to turbo and examine shaft play and compressor wheel condition.

But any other ideas?

[petbeemer]

have you checked the actuator on the turbo m8,make sure its fully closing?

As per what Pete has said - I had the exact same problem on my 6 not so long ago with the AVCR having to run at 90% duty just to get 1.3BAR !!

It was a dodgy actuator that caused the problem.

[TIM EVOIV]

i remeber you did say about that pete when you did my clutch and i had the M6 brake down ....

since then i got the few bits sorted and it worked fine.

i have changed the plugs but that shouldnt efect it .

it is a new actuator fitted by RSE about 2 months ago so it cant be that or are you meaning the spring/rod on the turbo end ?!

[petbeemer]

Originally Posted by TIM EVOIV

i remeber you did say about that pete when you did my clutch and i had the M6 brake down ....

since then i got the few bits sorted and it worked fine.

i have changed the plugs but that shouldnt efect it .

it is a new actuator fitted by RSE about 2 months ago so it cant be that or are you meaning the spring/rod on the turbo end ?!

correct m8 and if you remember we could hear something tapping inside the turbo elbow,drop your downpipe and have a peer inside