Boost Gauge Troubleshoot

[Grinder34]

On the way in to work today my boost gauge got stuck at like -23 mmHg at some point. After parking I did some basic trouble shooting. I unplugged the boost sensor and the gauge dropped to -30 (the lowest). I restarted the car and at idle, with the car off, and revving all register -23 mmHg. The power-on sweep of the gauge is fine.

I was hoping to get some ideas from you guys while at work about what could've caused it, things to check/log or whatnot, for when i go home this evening.

 

[HolyCrapItsFast]

do you have a variable 0-5v source?

simulate the sensor with a 0-5v source and that will rule out the gauge or confirm a bad sensor.

 

[Grinder34]

I dont have a 5v source

 

[Batmobile_Engage]

I would think that the Power-On sweep of the gauge proves the gauge has not failed, because
you can (at least on mine) disconnect the sensor/data signals from the gauges, and with power
alone, the gauge will perform the same sweep.

I would expect a bad boost sensor or damaged wiring. Are you talking about DEFI BF gauges by any chance?

 

[Grinder34]

nope, maddad 3-in-1.

I guess I should unhook the vaccum tube and a) see if it goes to 0psi, and b) see if i can feel the tube sucking in air. if !a, bad sensor. if !b, clog somewhere?

 

[Batmobile_Engage]

^ that was going to be my next suggestion.