Serious Boost problems (Overboosting), please help!!!!

[jrpmp69]

I recently installed a boost gauge on my 2g eclipse and noticed that the stock bov would only hold 12psi of boost, so i installed a 1g bov, now whenever i try to speed up really fast my boost gauge reads as much as 20psi, which i dont think is right. After noticing that the stock boost controller was pushing too much boost i went and bought a TurboXS HPBC and istalled it and set it to minimum boost and tried the car out and it was still pushing between 15-20psi, i completely removed the stock boost controller when i installed the TurboXS, i really need help in solving this boost problem, someone please help me.

 

[leet]

Check to see if your wastegate is working properly.

 

[jrpmp69]

How do i check my wastegate? Could it be the bov that may not be working properly also?

 

[slodsm]

Does it shoot up to 2o and then level off lower at like 14 or so or climb to 20 and stay there? Sounds more like a boost spike to me because you have such a quick spooling turbo but a stock o2 housing

 

[jrpmp69]

When spedding up, the more i press the gas the higher the boost level goes up, the turbo is stock, i have a 1g bov and a 5zigen 2.5" exhaust, and also a TurboXS HPBC set to 6psi to test it out.

 

[leet]

To test your wastegate, get an air compressor and set it for 15PSI. Attach it to the wastegate and pressurize it. If the wastegate is in working order, it should open up. Just do NOT use HIGH PRESSURE AIR for this.

 

[jrpmp69]

I just took my car for another test drive and the boost wnt all the way up to 15psi and i let go of the gas, when the boost pressure got around 6-7psi the needle on the boost gauge would stutter a litle and then continue. Also now my check engine light came on. i hope i dont screw up my car.

 

[slodsm]

Originally posted by jrpmp69
When spedding up, the more i press the gas the higher the boost level goes up, the turbo is stock, i have a 1g bov and a 5zigen 2.5" exhaust, and also a TurboXS HPBC set to 6psi to test it out.

There is your problem bro, the boost controller you have will not set to 6 psi, what it will do is screwed all the way tight, the factory waste gate controls the boost at I guess 10 or 12, whatever it is on a stock 2g, 2 turns out is 1 psi above stock and every 1 turn after is another psi. What you have effectively done is raise your boost 6psi above the factory wastegate setting. Screw it all the way in and start over.

 

[de_shadows]

i currently having the same problem with my 98 gst. i installed a mbc and a boost gauge, but couldn't get my boost to hold @15psi. the more i floor the higher the psi climb, (up to 25 psi). the mbc was purchased from dejontools; (MBC-2a) Lo-Hi Dual Controller
Switch between stock boost and your set boost ).

on the other hand when i switch to stock boost mode, it does hold @ 11 psi..

after market: intake, and 1g bov.
stock: exhaust, intercooler pipes and everything esle.