My 2nd turbo boost problem, part2........

[Sean1933]

as the WG VSV ha been cut and plugged, doesnt this mean that the WG does not see ANY pressure? how can this be right?

 

i have not done anything with the EGBV, i assumed that this was obselete when running in TTC?

 

This still does not help me get to the bottom of why the boost is not staying the same on tubby 2 when in normal sequential mode...

[Tricky-Ricky]

as the WG VSV ha been cut and plugged, doesnt this mean that the WG does not see ANY pressure? how can this be right?

 

OK what you have to remember is that there are TWO feeds to the waste gate and EGBV actuators so even though you have blocked the VSV the waste gate actuator is still seeing manifold pressure!

 

i have not done anything with the EGBV, i assumed that this was obselete when running in TTC?

 

In order to operate in TTC mode you need to bypass the EGCV VSV so that will make a big difference!

 

This still does not help me get to the bottom of why the boost is not staying the same on tubby 2 when in normal sequential mode...

 

Like i said in the other post i think you need to put in a restictor ring in order to have a constant, but having said that some rings need to be fettled to get the desired boost.

[Mike M]

The waste gate actuator has a pressure feed off the turbo pipework (big red Dot) then it's connected to the VSV which you say is cut and blocked both ways. That means the wastegate is seeing boost pressure and operating on it's own.

 

[Mike M]

TBH it sounds like a faulty vsv on the IACV or EGCV either one not opening fully will restrict tubby 2.

The EGBV will cause tubby 2 not to come on line till after 5k revs and make the engine feel very wrong and unwilling to rev.

I'd have that wastgate connected as it should then diagnose the seq system.

Seeing as it was fine in TTC, this has so far proved the IACV & EGCV actuators, pressure tank and hose connections.