4agze Problem at low rpm boost

[DavisJD]

Trying to work out what the problem is before i go back to the mechanics.
Thought it was an ECU problem but after talking through it with the mechanic on the phone and checking settings it seems its not.

So heres the setup;
4agze, fmic (lots of piping), wolf 3d ems

Heres the problem;
Car hunts on idle a little more than what it did before problem started.
Runs fine when u have high vaccum pressure (30-50) however if you put your foot into the accelarator, bringing on boost or low vaccum (0-20) the engine will not fire at all and makes a strange sound, almost like a belt rubbing, until you back off the accelarator bringing back high vacuum pressure again and then the engine starts firing again.
However if you slowly bring it up to speed with light accelarator work to keep vaccum high, once the engine gets to about 3000-3500 you can plant your foot and hit full boost and car runs fine until ur at lower rpm again when the same problem shows.

Have checked the belts and they all seem fine.

Same thing happends wether your sitting in neutral or in any gear.

Anybody have any ideas on what i could look at?
Should i post this up at toymods as well?

Any help would be appreciated

Thanks

[shift_rook]

I think you have answered you own question in your post , is there a air leak producting you strange sound ? or is it a s/c seizing at low rpm on the way out .

[DavisJD]

i dont think its an air leak, as performance is still the same once you get the revs up.
As for the supercharger seizing at low rpm, sounds like it could be that, are they known to start doing that when there stuffed?

[shift_rook]

Air leakage if small will be so hard to hear at revs , and yes there are known for that

[SprinterTRD]

Could it be that the SC belt is slipping? Not sure how your engine is setup with the efi system. but this could cause a lean out and cause what you are describing.

[DavisJD]

I could see it been any of these three things, il hav eanother good look at the car tomoz when its light again. Tightend up the SC belt though and didnt fix anything.
thanks for the help