-7 to 0 boost o gauge?

[apirateslife]

I have a question, my boost only goes from -7 to 0 when I'm running my z. I can hear the turbos winding, and I've had her at high rpms in 3rd, but the highest she gets on my boost gauge (stock speedometer) is 0, and when she is neutral, she only goes to -7. I can feel a small amount of boost, but she has oil blowing past her, as smoke blows out my tailpipes after i let off the gas when shes boosting. Would the -7 and 0 readings be from bad seals which i'm pretty sure I have, or from something else?

[evildky]

first I'd get a propper gauge, and make sure it's hooked to a good port ont he manifold, then look for any cracked or broker vac lines, then takk a good hard look at the idle air hoses, check the coupler form the turbo to the J pipe, and make sure the J pipe gasket to the TB is good and nto cracked,might be a good idea to go ahead and change the PCV valve, and have a good look at the your itnake manifold gasket

[Bleach]

You're talking about a factory 280ZX turbo, right?

I'm not sure what to make of that stock gauge. My Autometer gauge reads -19 at idle and almost 7psi boost.I'm not sure how the factory one goes from only -7 to +7

A manual gauge (like Autometer) will give you a more accurate reading. If your turbo really is not boosting then something inside of it totally broke. If you had a boost leak you would have some major misfires as soon as the manifold reaches positive pressure.Lots of oil going in will still boost, it'll just not burn as clean and you may find it runs rough.

[darrencooper23]

i have almost the same problem my car z31 boosts to 2 or 3 psi and i can feel a little boost but thats it i know it goes higher cause when i first got the car it boosted like crazy. i dont have the oil or tail pipe issue tho any one know why this is happening?

[evildky]

check your fuel pressure, mine died a long time agao and as boost rises, or as vac reduces raising fuel pressure and somethign that extra strain on a failing pump is snough to make it cut off