boost gauge problems after u.c.

[540James]

anyone have any idea why my boost gauge is vibrating intensly while accelerating? i just put in the unichip and unichip boost controller, maybe a vac leak somewhere? or is the boost controller? or the way i set the boost controller up? thanks

 

[540James]

i had my friend start it up while i listened in the engine bay, the buzzing noise is coming out of the boost controller solenoid(blue part of the unichip b.c.) and its making the buzzing noise in my boost gauge as well. did i hook it up wrong or its it a bad solenoid? thanks

btw, i replaced all vac lines and checked for kinks, all good and its still doing it

 

[EnjoyMinuteMaid]

what kind of a boost gauge is it?

 

[540James]

mechanical auto meter boost/vac

 

[540James]

man, i must say, this is the most booming, informative forum ive ever been to, so much discussion and help

 

[osu1steve]

I've seen that before on my gauge ... running a Greddy Profec BII and reading off an Auto Meter gauge. As far as i know, you are seeing pulses from the solenoid. It's rapidly pulsing the control value to target a certain pressure drop across the flow circuit, and you're seeing fluctuation in the signal. You're not supposed to be able to see the signal if it's working properly. I solved this problem by reducing the gain on the EBC. Hope that helps (and hope the info is as accurate as I believe it to be!).

 

[ccMSP]

You may need to purchase a "T" with a restrictor in it, similar to the one in the link below.

Restrictor "T"

 

[540James]

what will a restrictor do?

 

[osu1steve]

Well, it'll create flow resistance. So in theory it would increase the pressure drop across the fitting for the same flow rate, or for the same pressure drop, it'll decrease the flow rate. I guess it makes sense that it'll decrease flow rate so you won't see the fluctuation in the signal, but if you kink it off too much, the lag in the reading won't represent real-time. Hopefully they've properly sized a sharp-edge orifice resistance like what they're using so you'll see full boost when you hit it, and not a full second later.

Is there a gain setting on the boost controller on the UniChip? If so, you might try cutting that down a bit.