very low/no boost, only on primary turbo

[Johnerz]

hello
 
recently fitted an apexi and took the car out for a spin and i have little to no boost only on the primary turbo.
 
the commander reads around -54 builds boost very very slowly, almost none infact until 4500 when the 2nd turbo comes in, then its fine, car goes very strong.
 
there is no sound from the dump valve up till 4500, so im assuming that there isnt any charge in the system? above 4500 dumps fine on closed throttle.
 
there is also a slight \'whining\' sound which sounds like the turbine spooling???
 
now, as this looks isolated to the primary turbo, does this sound like a leak? i took the primary intake pipe of to check for cracks and the dump valve is off for the same reason.
 
can anyone shoot some ideas out or possible solutions? im still going over the vacuum diagrams to understand it and yes i have used the search function!
 
thanks folks

[Jono FD3]

Firstly I wouldn\'t take the RPM over 4000 on the base mape, specialy if you have the basic mods: exhaust & induction or you will run lean & cause damage!!

As for the boost issues it\'s more than likely to be a solenoid of some discription as if it was a split pipe you would have the same symptoms when the second turbo is online aswell!! actualy come to think about it, you might have the prespool actuator stuck open which means you will have very little boost till 4000rpm!!!

Jono

[Johnerz]

i was under the impression that the base map is fine with those mods?  
 
the irishrotary club is organising a group map with carl coming over so it will be going to that provided i can get to the source of the problem.
 
i was just starting with the primary air intake and taking it from there.
 
i see that there is plenty of threads on testing solenoids which ill look thru but which solenoid would be best to start with? (hopefully not the ones under the uim)
 
incidently these problems werent there until i took the car to have the boost/oil temp gauges removed (broken on the boat) my rear fog wired and the dvd/gps all removed. w hen i got the apexi and removed the stock ecu and knightsports ebs 4 i found a snipped wire which was taped away.  im thniking that they may have snipped it and not realised what is was and how to fix it so said fcuk it and taped it away.  so this may have caused the problem with the solenoid?
 
thanks for your help mate.

[Jono FD3]

You want to check that the prespool actuator is opperating correctly & free befor you go pulling the UIM off to onspect the solenoids mate!! might be something as simple as a broken pipe on the prespool actuator??

Jono

[RemarkLima]

Check on the Apexi if your ECU is registering speed, mine had a snipped wire to the ECU and it\'s the speed signal, as it seems to be the quick and easy way to get over the 112mph limiter

[Johnerz]

there isnt any snipped wires at all.  the wires that were snipped were on the knightsports so that is all fine.  as jono said it may be a solenoid or actuator.  its just a pain to get at them all and follow the vacuum diagrams!  
 
hopefully i can find a way so i dont miss the mapping session over here.

[Timmy]

I hope it is not this, but the whinning noise as it trys to spool can often be a knackered tubo. Take the intake pipe off and feel for shaft play.

[Johnerz]

hope its not that mate!  when the 2nd turbo comes on it dumps fine and there is no whining, so hoping its just a solenoid problem or a leak somewhere.  question is where to start!!!