FMIC installed, now turbo acting weird.

[eboy0]

Maybe this is quiet common, maybe not, but i'm not sure what it is. I just installed a fmic onto my 96 gsx, t-25 turbo, and now once i press on the gas, past o say 4k rpm in any gear, once i let off the gas, it like drops to 300rpm. No boost leaks found, ran the test. There is quiet a bit of a tubing for this little turbo, which is what i'm guessing is the problem. I'm running the tubing all the way through the bumper, hopefully the picture explains it. Can anyone diagnose this problem? Do i need a new turbo, or is something else causing this?

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http://img219.imageshack.us/img219/9387/p1010102bz9.jpg
I noticed that both my manual boost controller and stock one are having a delay in returning to normal? Meaning middle point.

 

[Denji]

ive yet to find someone who has more tubing with a larger core than myself. Due to an incident with my old turbo i have a t25 on my car iwth this huge intercooler. I dont have the same problem. I would investigate this and not set it aside as normal personally, only because of my setup almost certainly has more volume to fill. Have you checked the actual condition of the turbo itself?

 

[eboy0]

Worked fine before i replaced cracked stock ic + piping.

 

[No_Skillz]

If you have an MBC, why do you still have your BCS hooked up? Most people take the hoses off it and redirect to the MBC, but leave the BCS plugged in or it will throw a cel.

Also... I hope your BOV is recirculated or alot of people will be upset.

 

[eboy0]

Yes, the BOV is recirculated, it's a greddy type S bov.
Also, i dont have a MBC...?

 

[flashburn02]

I noticed that both my manual boost controller and stock one are having a delay in returning to normal? Meaning middle point.

Um? It said you tried a MBC. Regardless, pull off the tubing right off the cold side of the turbo. Be sure your turbine is spinning with no shaft play and you should be able to flick it and have it rotate smoothly.

 

[fallenauthority]

Ok, I have this problem too and im pretty sure i know what it is. The emissions tubes that run to your intake pipe, are they still connected? Or did you leave the hose from the valve cover disconnected? I did on mine cause i got a dejontool intake with no spots for the hoses and what happens is when you let off the gas from boosting and the intake returns to a vacuum state the pcv opens and is pulling in a bunch of unmetered air from your crankcase which is getting air from that disconnected line, causing the motor to almost die. Mine does it, just waiting to get a catch-can setup.

 

[CanadianTSi]

Ok, I have this problem too and im pretty sure i know what it is. The emissions tubes that run to your intake pipe, are they still connected? Or did you leave the hose from the valve cover disconnected? I did on mine cause i got a dejontool intake with no spots for the hoses and what happens is when you let off the gas from boosting and the intake returns to a vacuum state the pcv opens and is pulling in a bunch of unmetered air from your crankcase which is getting air from that disconnected line, causing the motor to almost die. Mine does it, just waiting to get a catch-can setup.

The PVC valve is connected to the Intake Manifold, so if it's pulling any air it would be meter'd air.

To the Original poster, it's not a turbo issue. Most likely just have a boost or vacuum leak somewhere.

 

[fallenauthority]

The PVC valve is connected to the Intake Manifold, so if it's pulling any air it would be meter'd air.

To the Original poster, it's not a turbo issue. Most likely just have a boost or vacuum leak somewhere.

Wrong. The pcv sucks air in from the crankcase to remove the contaminated air from the crankcase. Thus the pcv pulls air INTO the intake manifold. If the valvecover breather hole is left unhooked the pcv will be pulling air from the crankcase, which is pulling air from the atmosphere.

 

[CanadianTSi]

I know for a fact that it doesn't cause any problems.

Both my PCV Line and Valve cover breather line are open to the atmosphere.

 

[fallenauthority]

I know for a fact it does. My car was perfectly fine, until i disconnected that line and now it drops the idle stupid low when i let off completely from boost. Each car may be different and react differently, but I know for a fact mine does that because of the line being disconnected. Im just giving him a suggestion and a place to start from. Its worth a shot, and im willing to put money on the fact that if that line is disconnected and he reconnects it it will fix it.

 

[twack]

One day i blew my pcv (it was old and crappy) and i thought something big was wrong cause i had to rev it to keep the idle up or it would drop or die