Boost Gauge Fog

[andrewjscott]

Well, I'm having a bit of an oil burning problem, used to be all the time, but replaced the PCV and now its only on start up. Well I took the car out for a hard run and something weird happened....my boost gauge fogged up. What is up with that? My Boost gauge is tapped into my Fuel Pressure solenoid.

 

[dmndstrsfrevr80]

Boost gauge is connected to the fuel pressure solenoid? Do you mean the fuel pressure regulator? Pop off the line to your boost gauge at the vacuum port of your fpr. If fuel pisses out of it, it means the diaphragm on your fpr is blown and needs to be replaced...If it's a factory item, I would recommend buying an adjustable fpr. I didn't check to see what you have for upgrades, but if you have bigger injectors, Walbro, etc., it may be in your best interest to scoop one up for better tuning to prevent fuel cut, detonation, and to increase boost once the fuel system is improved. It will also have a vacuum port to reconnect your boost gauge and your "fogging" problem will be solved!

 

[andrewjscott]

no fuel upgrades yet, but definatly in the future. I'll look tomorrow to see if the FPR is no good. If not, i'll definatly look at an AFPR.

 

[andrewjscott]

Okay, no fuel poured out of the FPR vacuum nipple. So what caused my boost guage to fog up. It also had like a weird crystalization on it (almost like frost). I havn't seen it come back yet, but i've got my digital camera if it does. So what else could this be?

 

[Defiant]

I suspect the Bourdon tube's cracked, and you're generating a cloud in the gauge by pressurizing it and evacuating it. Old grammar school demonstration with a bicycle pump and a bell jar.
Be shopping for a new gauge.

 

[andrewjscott]

Never really thought about the gauge being defective. But wouldn't a crack in the Bourdon tube's cause my boost or vacuum reading to read much lower than it actually is? Cuz i'm still boosting to 15 PSI, like I always have, and still have 19 inHG at idle and 25 on decel.