yellowman

I've been getting mixed messages....Do I need to have the boost solenoid plugged in or unplugged after installing a MBC?

I've been getting a code 243 which is an overboost code, but my guage shows a steady 19psi, w/o spiking. hmmmm

I'm also getting a knock sensor code. po325. I checked my wiring on my SAFC II and it seems alright. hmmmmm

Thanks for any replies!

mikesevo8

You must leave the stock solenoid plugged in, the electrical connector that is, with the stock ECU.
Even with a MBC, the ECU still "thinks" it is controlling the boost.
With the solenoid unplugged, the ECU senses the open circuit, and throws the code.
A non-working (closed) solenoid will create an overboost condition; no place to bleed off the excess pressure.
Just plug the elec connector back in and tie wrap it (if the solenoid is loose) to something convenient so it doesn't rattle around.

yellowman

Thanks for the info!

advancEvo27

iTrader: (3)

you should try getting a vishnu cannonball to take off boost limiter $200 at vishnu

yellowman

What does that do? What is the boost limiter? I'm already boosting at 20psi and it holds pretty good.

GOKOU

iTrader: (2)

I have it plugged in and capped. Not sure if capping iis required.

dryad001

iTrader: (27)

Yup I keep getting the 243 code with the solonoid plugged in.

EvO6-RS2

iTrader: (12)

leave solenoid plugged in...then cap vacum nipples...I just ran one piece of vacum line from one nipple to the other, no problems.

osunick

iTrader: (8)

Actually the evo's solenoid is connected completely differently from an MBC/EBC. Therefore, a closed solenoid results in 16psi max boost, not an overboost condition. Basically the compressor nipple is connected to the wastegate with a T fitting that goes to the solenoid. When the solenoid is open, pressure is released to the intake. When it's closed, the pressure backs up to the wastegate and it opens.