Buddy brought over his 2004 Evo 8 to my shop. Car is been sitting for about 3 years untouched. last it ran it had a boost issue, was taken apart some and just left becuase he moved out of state.

Car is back together and starts and runs. Still has no boost.

What should i look into? Havent messed with these turbo cars in along time.

Tested the BOV, opens at 17in/hg vac so that is working correctly. per ALLDATA testing the wastegate it says with 16in/hg vac that it should open about 1mm and i got no movement from the wastegate. when releasing the pressure i heard something inside the diaphram make a noise. i dont feel any play in the arm/wastegate flapper area.

could the wastegate be stuck open?

car is bone stock aside from a clutch and a AMS manual boost controller.

i beleive they hooked that up correctly. looking at the controller with dial facing up, they have turbo nipple reference going into the bottom of the controller and out the side nipple of the controller to the wastegate. does that sound correct?

going to boost leak test tomorrow but doesnt seem like any leaks. car keeps vac normally.

 

This sounds like it's hooked up correctly.

 

Have you checked the turbo itself out? Does it spin freely? Is there any axial shaft play?

 

Does the car have a functional boost gauge? I think that base wastegate pressure should be about 11 PSI. Even with the wastegate's puck fully open you should see at least 7 to 8 PSI.

 

car has a brand new boost gauge in it.

turbo spun freely, and no shaftplay.

car drove perfectly fine but no boost. No sound of a leak, all piping is tight as we put it back in ourselves.

 

check all ur coupler's and intercooler for leaks, just do a process of elimination. Something is stopping the air or losing the air.

Could be wastegate stuck open check that

cheers

rob

 

Tell you what I would do. First disconnect the MBC and plug off al the open hose ends and unused nipples. Run a length of 4mm hose directly from the compressor discharge nipple to the nipple on the WGA.

Now, loosen the backup nut that secures the turnbuckle onto the end of the threaded actuator rod and pop off the cotter pin holding the turnbuckle onto the WG's pivot arm.

Try raising boost by rotating the turnbuckle in clockwise. First, adjust the turnbuckle to where the hole slides on and off the WG's pivot arm freely. Now rotate it in counterclockwise to where the pin covers half the area of the hole. At this level of preload you'll have to pull fairly hard to get the turnbuckle back onto the WG pivot arm.

 

Ill try that tomorrow and post back. When we got the car the WGA was off. We instaleld it and when I put the arm onto the pin it was lined up perfect to bolt into the compressor housing, didn't have to pull or anything to line it up. So not sure if that means at that state the flapper would be open or not.

 

Naughty, naughty! You should always bolt the WGA bracket to the compressor housing FIRST. Once the WGA is bolted to the housing, only then you may proceed to adjust the length of the actuator rod so that the hole on the turnbuckle's flat surface slides freely onto the pivot arm pin. Once the turbo/WGA assembly is setup as described, then you can start to adjust WG preload. It may be that the rod was setup too long and keeping the flapper valve open, or causing bind.

 

EDITTED due to repeat post.

 

pressure tested the boost/pressure side and everything holds great.

so looks like im moving to the WG

 

Finally found it!

everyone thought hte turbo was shot. so we got a boroscope camera up in the exhuast, all looked fine, started it again, and buddy noticed the exhaust sounded funny. pulled the DP and fired it up and got 7psi at idle reving.

plugged cat. WTF! at least our buddy already ordered turboback and its on the way.

 

Khuuul! Glad that you found it.