I just got my turbo swap running in my 90 GTU.
& could use a little help.

( S5 Jspec, all emissions removed, full TII drivetrain, No A/C or P/S,
N374 ECU, N/A engine wire harness,
N370 AFM & boost pressure sensor,
S4 TII coils, new NGK plugs & wires,
Knight sports FCD, walbro 255 fuel pump,
FD3S alternator, Dual belt pully,
ss autocrap FMIC w/ 2.5" pipe, greddy RS BOV 40mm, HKS wastegate actuator (8-14psi adjustable), TID mod, stock turbo, Thunderfab 80mm downpipe to Racing beat Turbo Catback, )
I'll be hooking up my SAFC & wideband after work today.

Ok, the car is running fairly smooth with no smoke.
But It won't idle unless I set the screw to keep it at 2000rpm.

I'm getting compressor surge every time I shift.
& It won't boost past 6psi while driving.

In a moment of noobism while trying to adjust my BOV without reading the instructions first, I tightened the crap outa the set nut,
instead of loosening the set nut & adjusting the screw..
completly stripping the theads as I went.

now the BOV won't let off any pressure at all,..

What now?, is it stuck?
I thought If I just tap the hole & put a bigger bolt in, it'll work?
but no,..
it won't release pressure even with the screw taken all the way out.
i'm still getting compressor surge.

Is the Greddy RS too "hard" for my application ?
or did I just f- it up beyond repair..


-Chris

 

Oh yeah,.;.
If my emissions are removed & the coolant lines to the throttle body capped,
Do I have to get rid of the thermowax?.. could that be why I can't Idle low?

 

My BOV seems to be working I guess,
but I'm still getting compressor surge.
when I let off the gas, it sounds like air trying to go back out the AFM.
and there's a ch,ch,ch, noise that comes from the turbo.

Here's a short of my car idleing high,
http://media.putfile.com/idleinghigh3
If I set the idle any lower it would die.
I tried unhooking the fast idler cam, but that didn't seem to do anything.
Should I just go ahead & do the trottle body mod, since I allready have the coolant to the TB blocked off?

Do I have the adjustable wastegate set too high?
I tried to set it to release at 12psi.. could that be my problem?
..but I'm not hitting any more than 6 or 7 psi..

I'll adjust it down to 10 & see what happens.
-any other suggestions would be appreciated.

 

It looks really nice so far.
I don't know how well the N374 ECU will handle spark timing

Yes- I'd go ahead with the TB mod. It simplifies things.
Is your idle let down dash pot already removed?
I got the ch-ch-ch in the AFM when I took the dash pot off.
I assumed it was the AFM plunger bouncing.
It went away when I finished the CAI. I am using the stock cold air snorkle and I think its slight restriction rebalanced the intake.

 

Thanks man,
its the Jspec motor & Jspec ECU, what'll happen to the spark timing?


I havn't removed the dashpot, & I just realized that what I thought was the fast idle cam was something else that I unhooked.
I'll go ahead & do the TB mod & hope that solves it.


My TID pipe is a short 2.5" 45,
would I be better off with 3"
or would that really make a difference?
Isn't the AFM bouncing because there's pressure bouncing back through the turbo?
It seems like I hear that ch,ch,ch, noise at the AFM, but I don't ever hear my BOV.

 

since my last post I've done the TB mod,
switched to a 3" TID,
hooked up an MBC,
adjusted my wastegate & BOV.
took out walbro 255, & installed TII fuel pump.


I'm now able to hit 12psi.
& it runs good while driving, except it dies while braking & almost dies during shifts.

It still won't idle, unless I adjust the stop screw to hold it at 2200rpm.
..any lower it dies.


I don't think I have any boost leaks since I have no problem boosting.,
And, If I turn the Idle stop screw down before starting the car, It will hold a lower Idle solid for about the first 10 seconds it runs, then it will dip & die.. Unless I keep bumping the trottle.


seems like an electrical problem,? the way it'll hold a good idle at startup & then die off,

I'm using the modified NA harness.
If I did hook something up wrong, what would cause these symptoms?

I'm also using S4 TII coil & ignitors, & this is an S5 car,.. could this be causing my problem?

 

Also, I should mention,
My TPS is adjusted.


And, Is there any way I can set the timing, if I can't get it to idle?

 

u sure u don't have any crazy vacuume leaks? u might wanna pressure test the system...

try putting the stock TMIC back on for a little while to make sure everything is ok...


usuallly no idle is a TID or vacuume leak problem...

u said u had a wideband... u can see how rich/lean u are below 2200 rpm... (i'm guessing very rich)

 

Havn't had time to hook up the wideband yet.
hopefully I'll get that done tomorrow.

I'll check for vac leaks again, but don't you think its unusual that, When I start the car,
it runs good for about 10 seconds,.. before the idle starts to drop off & die.

Could a vac leak make it act like that?

 

what condition is your TID in?

any cracks/ holes/ leaks etc? even a small hole can make the metering all off...
in my S4 the little tiny hole below if I leave this unplugged the car will try to idle and eventually die...

if the TID pipe is not super secure all the way on the mouth of the turbo with no leaks.. it'll idle a little then die

 

My TID's OK, but I did find a leak in my IC pipe couplers,
I double clamped it & the car will idle at 750 now,
but it still want's to die on decel & in between shifts.
I've adjusted my TPS several times.
should I put the BAC back on?,..
will that even make a difference?
I have no PW/PS/AC or radio.