little mark

I just picked up a 94 all stock except cat back.

The secondary boost sometimes wont spool up.Sometimes it does,sometimes it doesnt.The first spool is fine once it hits that certain RPM for the second it goes to 2-5PSI.When I first drove it this morning it worked boosted to 10psi through the whole rpm band but after about 10 mins it started with the drop off.But it did still spool to 10 a couple of times.Is something sticking maybe or clogged?
Any ideas? keep in mind please tell me in detail what to look at on the motor.Im clueless right now

Thanks for Any help

dubulup

sounds like cracked vacuum lines or tired solenoids.

To troubleshoot the system is a full weekend worth of down time. First thing I would do the black box in front of the Upper Intake Manifold. You might need to remove the crossover pipe in front of it.

Look under that black box and to see if you have any broken or disconnected vacuum lines...look everywhere. If you find nothing, you might have to remove the UIM and replace all the vacuum lines...this is where the fun begins.

little mark

All the lines were replace at PFS with silcone lines.But I'll start looking at the box your talking about.Thanks...Any other thoughts?

Mahjik

iTrader: (1)

http://www.autosportracetech.com/RX-...leshooting.htm

little mark

Thank you

dgeesaman

iTrader: (7)

You can do pinpoint tests without tearing things all apart. It sounds like a solenoid problem, and usually it's the turbo control solenoids. But that doesn't make it the answer. Basically, you put a boost gauge on the line between the actuator and solenoid using a tee fitting, and take it for a test drive. The sticking solenoid won't transmit vacuum/pressure at the proper time. Since you've had the hose job done already, this might be the most efficient approach.

silverTRD

iTrader: (37)

irs very possible that it is the primary turbo inlet, it works untill the car is hot and then the rubber is more prone to leaking. when both turbos come online its a lot more volume than just the primary turbo, so that may be something to look at. check out fd3s.net it has a good troubleshooting page as well