I have a b18 turbo with external wastegate. Controlled by a Mac 3port and s300hondata.

suddenly my car started over boosting and hitting boost cut. So I thought it was a faulty solonoid. Picked a new one up and went for a spin and it was fine. Next day overboost.

iv checked my solonoid and Iv got 12v to it and also the pwm is fine as I’ve done the test that hondata suggest and it works.

so I though it’s got to be my wastegate. Took the hose of the top of waste gate and with a 15psi spring I’m still hitting boostcut at 27psi. So I took waste gate of and inspected. All seems fine. Put my compressor onto my waste gate at 10psi to bottom port and it opened right up no issues. So I know that’s good.

so I’m abit at a loose end. Why am I overboost I g when everything seems to be working🤷🏼‍♂️

 

Found the issue I think. I took my wastegate of. Took it apart and then rebuilt it. Nothing seemed to be wrong with it. But doing this has seemed to fix the problem.

 

what wastegate do you have?

 

Turbo smart compgate40.

 

gotcha. Don’t know much about that unit.