Rb20 Guys I Need Your Help!

[1990_RB20sx]

Okay so i just bought an rb20 240 and im new to the turbo scene! Now my problem... the car runs perfect up to about 5k and then it seems to either get a fuel-cut or it seems to just drop off but only in first and second! The car is running 11 psi with no tune of fuel upgrades!! What could my problem be? Thanks for any help!!

[Carl H]

check for boost leaks...

[1990_RB20sx]

How do i go about doin that? I have this like tea kettle noise coming from the engine under full boost! Could that be a boost leak?

[mott6904]

If you go to the tech section i think there is something about how to build a diy boost leak tool.

[driftnslide1]

could be fuel cut. stock fuel pump to walbro? up fuel pressure?

[krispenev]

you're rb20 is at 11psi??? It probably has a boost leak...the rb20 needs a fuel pressure regulator at that psi...especially with the stock fuel pump...or the MAF is probably acting up...mine used to do that....sometimes the sensor would just cut out, and the computer could not regulate a/f. I suggest you set the boost to 7-8 psi until you figure it out. Sometimes, if you buy air intake cleaner (hard to get...stores dont usually sell it...its highly poisonous) and you take the air filter and maf off...and spray the sensor, it cleans it and could solve your problem until you find a new mass air flow sensor. GIve it a shot

[1990_RB20sx]

Okay thanks man!! I turned the manual boost controller all the way down and its still running 11 lbs. what could be the deal there? And do you kno where i can gewt a new MAF? And a good fuel pressure regulator for a decent price?

[Carl H]

remove the mbc and see if it does it, if not then the mbc was either installed backwards or is bad.

[Coolwhip]

the kettle noise usually is a boost leak.

Google "turbo boost leak tester" or "boost leak checker"

or a variation of those words.