Boost issues

[pitesy]

Hi,

so I am having boost issues lately. Three things changed since the car was normal: rebuilt turbo install, FMIC install, recirc bov removed.
In 2nd max boost is 6 psi, struggles to achieve this amount. In 3rd and 4th climbs up to 7-8psi, but only around 6000rpm. In 5th couldn't achieve more than 6 psi. (4.3 diff)

Other things:
- Fuel comsumption is normal.
- Bangs like mad during gear change (maybe because running no bov?).
- The cooler pipes and joints were tested for leaks only with brake cleaner, couldn't hear RPM change.
- Idle is steady.
- The car pulls okay, but is a lot weaker than before.
- Stock boost solenoid, stock ECU.

I have two guesses:
Either boost leak, or the actuator has seen better days, or was badly set up by the turbo overhaul company (arm fallen off maybe?)

Any ideas where I should start looking? The pipework on the FMIC is crap (egay cooler), just ordered the PBM high mount cooler, I wish I bought that first... Didn't have time to go under the car, to busy with work sadly... But hopefully I'll be able to check a few things tomorrow.

Any ideas, help, input is more than welcome!

Thanks a lot in advance!

Best regards
István

[S14DB]

Carb cleaner or starting fluid only works on vac leaks. You can still get boost leaks that don't open up till under boost.

Make a boost leak tester by going to the hardware store and getting a rubber plumbing cap the size of the turbo intake. Drill a hole in it then install an air tool fitting in the end. Hook it up-to a compressor/air tank at double you PSI(no more than 30). listen for leaks and use soapy water spray to hunt them down.
Google "diy boost leak tester" for examples.


To test the wastegate pull the vac line to it and insert a hand pump(or air tank at actuation PSI) nipple into it. Pump it up and it should start moving as you get close to actuation PSI.

[pitesy]

Thanks S14DB! Will do both the above mentioned definitely as soon as I have some time.

Does anyone have opinions on ebay boost leak tester kits? To ba fair I don't really have a lot of time due my job, and there aren't many stores around here to make my own one... I know they might be a bit overpriced for what they are, but how would you rate them?

For example:
Turbo Boost Leak Tester Pro - Pressure test any car for boost leaks | eBay (http://www.ebay.co.uk/itm/Turbo-Boost-Leak-Tester-Pro-Pressure-test-any-car-for-boost-leaks-/300932538608?pt=UK_Diagnostic_Tools_Equipment&hash=item4610fa20f0)

Thanks in advance!

[S14DB]

Thanks S14DB! Will do both the above mentioned definitely as soon as I have some time.

Does anyone have opinions on ebay boost leak tester kits? To ba fair I don't really have a lot of time due my job, and there aren't many stores around here to make my own one... I know they might be a bit overpriced for what they are, but how would you rate them?

For example:
Turbo Boost Leak Tester Pro - Pressure test any car for boost leaks | eBay (http://www.ebay.co.uk/itm/Turbo-Boost-Leak-Tester-Pro-Pressure-test-any-car-for-boost-leaks-/300932538608?pt=UK_Diagnostic_Tools_Equipment&hash=item4610fa20f0)

Thanks in advance!
Oh I just noticed you are in Hungary. But that is a good design as it is a clone of one of the OG kits.
Boostpro.net : Products - Boost Leak Testers (http://www.boostpro.net/prodtester.html)

It would be hard to recommend produced ones as I don't know who would ship to you.

[fliprayzin240sx]

Make your own boost leak tester. All you need is some 3" coupler, a few clamps, a 3" pvc pipe cap, a wheel valve stem.

[S14DB]

Make your own boost leak tester. All you need is some 3" coupler, a few clamps, a 3" pvc pipe cap, a wheel valve stem.

Re-read the thread... :Ownedd:

[pitesy]

Thanks a lot for the ideas and the links for the testers!

However I have a smaller update regarding the issue.

Read somewhere that you can test the actuator by removing the actuation pipe, but you have to be extra careful, because this way there is unlimited boost.
Tried it, picks up mega fast and around 3500 it wanted to go very quickly above 10psi, and I had to release the throttle in a second or so, because it wanted to spike immediately and didn't want to damage anything (I wasn't near to fuel cut, so nothing stupid happened :))

So I assume if there was a bad boost leak, it would still struggle to achieve normal boost levels even with "unlimited boost" actuation.

The stock boost controller was clicking earlier a lot under load, now it's completely silent. So I assume that either the actuator or the boost controller needs to be changed.

Please someone back me up, correct me! :)

Thanks in advance!

[Mikester]

Sounds like a bad actuator.