ok so this started 2 days ago and it has me stumped so i am wondering if anyone could help me out. in first gear when i stomp on it i can gradually watch my vac lower but never go into boost. in second i'll stomp on it and i'll get 2 psi max at about 5500 rpm. today i did a visual check on all my sillicone couplers and they all appear to be in good shape and no leaks, i disconnected the wastegate and drove down my road still the same case, and i also took off the air filter and the turbo (rebuilt 400 mi. ago) is spinning just as smooth as ever.
#97398, "RE: help!!! no boost!" In response to Reply # 4 Sep-21-06 01:32 PM by thedawg
If you have the HRC SMIC, the elbow coupler right under the fusebox likes to blow off, and it looks just fine. Take out the plastic fender liner, and crank it in good.
To do a boost leak test, just take off the hard intake pipe, wrap the base of a full beer can with a bit of duct tape, and clamp it in place of the intake pipe. Pull the vacuum line off the wastegate actuator. Connect an air compressor (turn the regulator down to 10psi!!!) to the vacuum line. The little nozzle just about every shop has for cleaning up can be used here, just remove the rubber tip. http://www.expeditionexchange.com/powertank/DSC05528.jp g
If it's not a boost leak (it probably is) disconnect the wastegate actuator, pull it off the pin on the turbo. Then swing the pin back and forth to see if the wastegate arm is functional and closes properly. If it feels really light and easy to move, you may have to pull off the HRC downpipe and visually look at the wastegate flapper to make sure it's closing all the way.
If it's not the flapper, it could be a bad actuator, or your vacuum source to the actuator could be bad. Try connecting a brand new, short 6"ish vacuum hose directly from the turbo outlet nipple to the actuator.
#97419, "RE: help!!! no boost!" In response to Reply # 5
ok this morning i had a chance to check things out closer. i went up and down my intercooler piping to the front mount and back, no leaks. i checked the wastegate and its is working 100% and the flapper is opening and closing just fine. so now i am thinking about how last week i had problems with my dis-2 causing really bad backfiring problems. do you think it could have destroyed a turbine fin and it just broke off with in the last 2 days and now the turbo wont spool because of it? i didnt have a chance to un-clamp the v-band and drop the down pipe, i'll hafta do that tonight when i have time.
#97479, "RE: help!!! no boost!" In response to Reply # 7
Ok guys, i had the time this weekend to figure it out. When i was experiencing the really bad backfiring from my dis-2 acting up it destroyed the guts of my maxflow cat and caused so much back pressure that the turbo would not spool. What i did is i dropped the cat and made my self a 3" test pipe and it spools quicker than ever!