ProSport boost gauge issue?

I just hooked up my electric boost gauge and when my turbo starts to spool the gauge is still reading 10 in vac. then when my turbo is fully spooled the gauge is only reading 5psi.

Anybody have any ideas of whats going on?

Thanks, Cameron

 

[Diego]

Is this the one that has the little box with 3 wires, I have the same, yet to hook it up but I will shortly... I'll stay tuned to see if you fix it.

 

[conquesttsi]

Vaccum leak. What are you using for a source?

 

FP solenoid line

 

[conquesttsi]

Aftermarket FPR? Do you have the input to the solenoid still hooked up with the output going nowhere by any chance? If that was the case the open solenoid could cause a small vaccum leak leading to this condition but not bad enough of a leak to cause any real operational issues.

 

No stock FPR and everything seems to be hooked up fine!?

 

[conquesttsi]

Got a mechanical you can throw in just to see if it's the gauge? Otherwise I'd start looking for a vaccum leak (a small one). You might want to get out the soap and water for this one if you can't hear it.

 

[mikus]

^ ya I'd not worry so much about location as boost leaks and gauge.
- boost leak test (this should be first step for so many issues...)
- try two sources to eliminate source as variable
- hook up two gauges to eliminate gauge as variable. I always keep a tested spare mech. boost gauge for this, they're so cheap used...

 

I hooked up a mechanical boost gauge today and everything read fine.. Is time for a new sending unit?

 

[3rdstrikedsm]

Every pro sport gauge I have seen has failed in one way or another.

 

[conquesttsi]

Intresting. I use prosport gauges. I have a mechanical 30/30 boost gauge and an oil pressure gauge. I Had them in 1933 for 2 years with no issues.

I personally have never been a fan of electronic boost gauges. I guess it could be the sending unit..or the gauge, without spares to swap out it's a guessing game. Unless somone on here knows how to check them with a VOM?