overboost problem > ECU CUTS BOOST FOR SPLIT SECOND

[wkdkris]

ok so my z20leh is overboosting to high for the ECU, the ecu cuts boost for a second, then when it allows it to re-boost, it holds at the correct pressure of 0.7bar (13psi ish)

what would cause the boost to go so high??(1.5bar 22psi ish)
there is a horrible noise/vibration when it overboosts and its actualy slower then when it just boosts to a normal level (rarely and its much much quieter and smoother)

possible the wastegate is been blown open (it would explain the noise and boosting far to high) but how comes after the cut back, it corrects its self and runs fine through every gear?

im not sure if it peaks out at 1.5bar or if thats the highest it gets before the ecu backs everything off.

it has a new dump valve, boost solenoid on order

any suggestions????? if aboves to confusing..... why would it be overboosting????

[wkdkris]

bump

[Rs1]

Its not blowing the gate open.
Has this happened since fitting the new dv?
If all is good in terms of pipework, dv, bcs then it could be bad actuator adjustment. If you have it wound up it will try to boost but then the ecu will try its best to control it to save the motor. The ecu is quite good tbh as actuator adjustment doesnt nessesarily give increased held figures that everybody wants/tries to do but more so just increase the spike on first appliaction of WOT.
If you cant suss it i'm pretty sure Chris Reay could take a look and get running spot on...... for a small fee

[wkdkris]

ive been trying to get chris reay he has my number but i never got a call.......

No its always done it, i tried the changing the dump valve as it sometimes opens when cruising at 70 and makes the car run crap. But nothing changed. I have no idea how its setup as i never done it, but i havent touched any of it. Theres a slight hissing around the top hat, not sure if its normal, its to quiet. So im going to take that off and use abit gasket seal to see if theres any difference and I have the new front BCS in my hand now to go and fit.

I get what your saying about the actuator too, when i've done the above im going to test drive it and if its no better il try slacking off the actuator. Im guessing the worst that can happen in that case is low boost or non at all if over done?

Thanks

[Rs1]

Do you know who done the conversion?

[wkdkris]

vinny, the lad i bought it from

[Rs1]

Ah ok, yeah Chris doesnt like to muck about with other peoples conversions as 9 times out of 10 they arent done right and he would end up wasting alot of time correcting it.....which could then cost you x amount.
If you do get absolutly stuck i could give him a nudge like

[wkdkris]

to be fair to the lad, the conversion is very tidy! nothing has been spared, its an 09 engine so was pretty much lifted out and in as a lump with new everything..... Ive done the front BCS, its much smoother and does drive better but hasnt solved the spiking boost problem. I would apri if you could give him a nudge ive had this issue for a while now and ive progressed from loss of boost to understanding why... but not what the cause is! + i could spend x amount fannying on with it tbh lol

Cheers

[Rs1]

No probs, will give him a nudge.