help.

[highimeric]

hey i just bought my first 240sx with a sr20det red top. i drive it home four hours and it drive fine. but today when i was driving the boost gauge stays at about -15 and when i accelerate it goes up to zero. where as before it would go from 0 to 12 when i accelerated and when i let off the gas it went to -15ish the settled at zero. just form trouble shooting i think it means the turbo is not working but i dont know why or even if thats the reason. i need some help. thanks

[hpmachine]

Does it still feel like it's building boost even though the gauge says zero? Could you have a boost leak? Is it running rough or really rich?

[Hijacker]

did you check for a boost leak? or did you check to see if the wastegate actuator arm fell off the wastegate door? I've had that happen and the car just simply wouldn't boost.

A failed turbo usually gives you a bit of advance warning before it totally craps on you. And if it does just crap on you, you would know (good old sounds of metal scraping and the like)

[spikNspan]

Well first of all did it feel like it was pulling just as hard as it was before you noticed this problem? If the car drove the same then maybe the gauge is just messed up.

and also, your vacuum shouldn't settle at zero while you're idling. it has to be a vacuum problem if it isn't just the gauge.

[IanS]

did you check for a boost leak? or did you check to see if the wastegate actuator arm fell off the wastegate door? I've had that happen and the car just simply wouldn't boost.

A failed turbo usually gives you a bit of advance warning before it totally craps on you. And if it does just crap on you, you would know (good old sounds of metal scraping and the like)

[highimeric]

yea i checked for a boost leak none. what should the gauge say when the car is idling?

[highimeric]

its not really running "rough" but there was some smoke or vapor or something coming out the exhaust when i shifted. and my air fuel mixture gauge isnt even reading or theres one bar. not really sure what that means either.

[doridori23]

yea i checked for a boost leak none. what should the gauge say when the car is idling?

idling aprox 20 vacuum. If it reads 0 and the gauge is good you have a leak no question about it. What color and smell was the smoke? If it was white and instantly disipates it is water and your looking at doing a head gasket. If it does not dissipate instantly and is white your running lean and dangerously so. Is there any detonation/backfiring? How does run when in gear cruising and with moderate acceleration?

[highimeric]

my gauge was messed up. as for smoke i think it dissipated but the guy i bought it from said he just did the head gasket. it doesnt do it all the time though. and it runs really cool too no over heating. and its never backfired. it cruises fine all day long.

[Hijacker]

Holy double post that are 2 days apart batman!

delorted aditional post, but this will at least leave your thread bumped

did he replace the HG with a stock unit or a multlayered metal? the metals can tend to leak coolant

[highimeric]

my gauge was messed up. as for smoke i think it dissipated but the guy i bought it from said he just did the head gasket. it doesnt do it all the time though. and it runs really cool too no over heating. and its never backfired. it cruises fine all day long.