Zd30di gu - no boost

Hey guys,

currently experiencing boost issues with the old girl and hoping someone might know something obvious im missing.

Basic Zd30di, tillix valve, turbosmart map spacer/2 fitting. Now randomly the other day i realized i was only running 10ish psi of my regular 15, i pulled over and fiddled with the needle valve with no luck, so i drove to work and thought nothing of it. Get in the car that afternoon and i could only get 5/6psi.... fiddled with the tillix some more and now im pinned at 2psi. No weird noises, no strange behavior, no check engine lights, just runs like a bag of balls, makes 2psi at the best of times and EGTs go through the roof. Things i've tried so far:

Maf clean
Map clean/reseat
Checked all intercooler piping
checked all vaccuum lines
Run without needle valve
ECU reset (battery disconnection)
lubed up the VNT arm on the turbo (moved freely but you can definitely feel the pressure behind the spring!)

another thing worth noting, when id usually disconnect a vacuum line from the turbosmart spacer, you could feel a strong pressure "pulse", when i do that now the pressure is essentially non-existent. Running out of ideas fast! Anyone experienced similar or have any suggestions?

Hey
Really sounds like a vacuum issue.
Try taking the vac hose off the actuator on the turbo and see if it moves at all , it should pull up when connected and when adjusting the needle you should be able to make the arm drop
Cheers and good luck


Proud BTrol Owner
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in the interest of future members with similar issues (nothing worse then finding a relevant thread about an issue with no resolution noted) i found the problem shortly after this post!

Had another look after reassuring myself I wasn't going nuts and it sounded like a vacuum issue and I found the fitting under the top mount had become brittle and decided to snap in half, missed it the first few looks as the damage was covered by the heat protection shroud, quick line change and we are back to full boost! Next job will be replacing all the vacuum lines under the top mount, these poor lines are subjected to some harsh conditions and simply just become brittle so easier to fix it before it becomes an issue!

Attachment 77180

Well blimey, same issue with mine today, out of nowhere loss of power during acceleration, boost almost non-existent prior to 3000rpm, exhaust making a loud booming sound during driving and noticed engine bay was very hot, no smoke noticed.
Searching posts for an hour and happy I found this one, as I did just about all the things JoelyMoley did except for check the hoses and bang there it was a split hose. Never expected it as the hoses are fairly new.
My boost and acceleration are back, quiet exhaust, very happy.

Attachment 78073

Wouldn't find this solution on Face Ache would you? Your respond would be. Just send it!

That vac pipe to the actuator looks like it had a lot of pressure on it due to apparent bend in the hose. Reduce its length so connects to the actuator diaphragm housing as straight on as you can get.
.

you can buy boost adaptors that fit under the OE boost sensor one makes life easy if fitting a boost gauge.
Replace all boost hose with some EFT 4mm rubber hose cheap as chips, an oily intercooler
will mean its leaking , buy a new fully tigged one from Diesel Smart 33% bigger

If its an early GU zd30 check that the vacuum tank isn't cracked