boost controller????

[MARINES185]

ok, I bought a bstc from fullthrottlespeed and hooked it all up.
well, it doesn't work. the red led comes on and even with
the knob set on high the boost is still the same 16lbs but
then I get a check engine light and code 31. so I checked
the voltage at the waste gate solenoid and I have 12v on
each wire. so how can the soleniod work if it has 12v going to
it on each side? I ohmed the pink/black wire at the ecm to
the pink/black wire at the waste gate soleniod and got .3ohms
and when the key is on I get 12v on that wire, but I assumed
the other wire purple/white from the waste gate was the
ground wire controlled by the computer . maybe I need a
wiring schematic. someone please let me know whats going on.

 

[scottyb]

Double check the wiring. The diagram that they send isn't very clear and you can easily confuse the correct connections.

If the BSTC has power and you're getting a 31, then the BSTC isn't hooked up to the ECM correctly.....ECM throws a code.

If the BSTC has power , but you have no boost adjustment, either:
1. trigger is not activated, ie correct tap to TPS for most installations (red light will not come on), or
2. incorrect tap from BSTC to solenoid.

Since you are getting the light, it looks as if you may have the ECM hooked up to the BSTC where you should have the solenoid hooked up to the BSTC, and vice versa.

Hope this helps.

 

[scottyb]

I just noticed you said you don't have a diagram. Let me know and I'll scan mine for you.

 

[scottyb]

bstc diagram

 

[MARINES185]

I figured out what was wrong. I connected the white and
brown wires to the boost solenoid wire but then I reconnected
the purple/white wire back together so the controller was
putting 12v in that wire and ecm put 12v in the other wire to
the solenoid. the problem still was there though. I set the
tps trigger low and listened for the wastegate solenoid to
click. yup, it worked. so I take the car for a drive and the most
boost I can make is 10lbs even with the boost controller on
max. now the interesting part is that I have an external
wastegate that has a 1.5'' exhaust off of it. yes, I know thats
big. with an air regulator i found out that the spring is set
to open at 17lbs. the only thing i can figure is that when it opens
to much exhaust is routed away from the turbo and the waste
gate solenoid is not bleeding enough boost off. heres my idea
that worked. the purge solenoid on top of the charcoal canister,
thats the round thing on the drives side of the engine compartment) will plug into the wastegate solenoid wire harness.
this solenoid will bleed lots of boost off. now I have adjustability
with the boost controller to go from 10lbs to over 20lbs.
I'm not sure how far it will go but at 3/4 knob turn it was just
over 20lbs. this maybe an alternative to running two boost
solenoids and you could get the purge solenoid off most
GM vehicles in a junk yard.

 

[Drac0nic]

Originally posted by MARINES185
and you could get the purge solenoid off most
GM vehicles in a junk yard.

Ever tried this? How much boost do they take? hate to hijack the thread, but I was thinking about using an EGR control solenoid like they use on the TBI stuff for a boost control solenoid. Then again a real boost control solenoid for a Sy/Ty is about $10+a fortune in shipping from gmpartsdirect.com, 1997152 from syty.org's part number list.