Boost Needle Jump

[Regc10]

Hey guys, my S15 boosts around 0.7 than under high revs and high boost the needle starts flickering wildly. what could be wrong?

 

[meddler]

I take it you car is JDM? If so, I would look for a leaks (cracks or damage) in the piping to the boost sensor or damage to the sensor itself. It could possibly be the gauge. Do you have another gauge you can try?

 

[GUEST_JDM]

sounds like the map sensor is on its way out, that sends the signal to the guage

 

[JaseYpk]

ive noticed a lot of topics about this recently (including mine) my boost gauge is going crazy too.. the answers most people came up with were check all the boost pipes and ensure theyre not damaged, like meddler said, or that the actual gauge itself is faulty?

 

[Regc10]

Boost

hey guyz thanks for all the response. The needle fluctuates widely at high boost. i asked a mate of mine and he said that the internal waste gate leaks under too much pressure, so a external should fix the problem. The gauge itself is fine, no issues there. I have checked all the piping, they are fine.

Also just wanna know, my brother has a S15 1999 model and his standard boost is 1bar, no mods except for filter, exhaust 3 inch and ssqv bov. Mine is 2001 model but my standard boost is around 0.5 and peaks at 0.7 and then da fluctuating needle kicks in lol. I checked out this forum it said something about the boost solenoid, i dnt think he's one has been removed.

 

[Jay]

if your brothers boost is 1 bar then its not standard. the standard is your 0.6/0.7 bar. this can be achieved by a simple mechanical boost controller (i have this and set to 0.95 bar)

 

[Regc10]

to: jay

hey bro, i've seen his engine, its fully standard no mods apart from an exhaust, maybe someone took out the solenoid lol.

 

[Jay]

or the boost guage is reading incorrectly.....

 

[andeep]

If someone took the solenoid out, the boost would be actuator pressure which is 0.50 bar I think

 

[Re-VolveR]

i have this problem too. needle jumps from 0.85 to 0.9(approx.). but i think real boost is stable.
PS i have stock boost gauge.