Strange Boost Readings Tonight

[WSU99GSX]

This just started tonight, for some reason when my car is at idle the boost gauge reads alittle more then 20, before it read always about 15. Also when I used to let off the gas it would drop to 20, now it drops to 30. Also with the boost controller set like it is right now the car won't boost over 10-12, however I can't hear a scream that would lead me to think it was a large boost leak. Nothing changed tonight, and I looked and all the lines are tight and hooked up. Any ideas?

 

[WhiteTsiAwd]

Did the weather change? My vacume changes with the weather. Mostly temp. If not then double check vacume lines for cracks, and splits. Or if one is just not hooked up. However your vacume went + so I would doubt that you have any lines unhooked.

 

[WSU99GSX]

The weather hasn't changed, and that is just it, it is strange that my vac would increase...I set the boost controler all the way up, the car hits 15 then drops to about 12-13, and then falls down to 10 like the T-25 does...could it be that something tightened on its own or something stupid like that....

 

[flytalon93]

I would say first to run a boost leak test and post results.

 

[WSU99GSX]

I did read on here that sometimes the thin plastic tub that comes with the boost gauge can go bad, so I am going to replace that with a vacum hose tomorrow and see if that helps. If it was a boost leak wouldn't the vac be closer to zero? Rather then go from about 15 to 20 at idle?

 

[WSU99GSX]

Could a boost leak effect vac? This car is an automatic not sure if that changes anything, what worries me is not the idle but the fact that the vac drops to -30 during deceleration.

 

[WhiteTsiAwd]

Yes a leak would affect vac. but i dont think it would make it get +.

 

[WSU99GSX]

Got it! When I got into my car today to start working on it I noticed that my Autometer Cobalt electronic boost guage was sitting just shy of -10 vac, with the car off. It is suppost to be at 0 with the car off, so I adjusted my MBC so that this gauge says I am pushing 10 psi, where is was when this happened. I am going to order a new guage right now and then send in the old one for warrenty, not even 6 months old. Thanks guys!