AAZ Turbo

[Mark S]

Excuse my ignorance but can anyone tell me when the AAZ turbo kicks in? Is it pretty much blowing the whole time or does it respond to certain conditions? Does the rubber hose from the top of the injection pump to the turbo area have anything to do with actuating it?

Many thanks.

[VirginAtlantic]

When did you have your turbo serviced last? Perhaps it's time to send it off and see how it runs on a test bed? Sounds to me like your waste gate is potentially jammed.

[VirginAtlantic]

Oh and just check I guess you've already checked the obvious split pipes and poorly sealed connections to and from the turbo. You don't want a simple thing like this to cause you to lose boost.

[Mark S]

Thanks for the replies. I should have clarified that I am actually using a JX turbo on an AAZ with an AAZ pump. I have been running this setup reliably for 13 years so it's not a recent lash-up. The turbo was new/recond when fitted and has done around 35K miles. I don't suspect anything wrong with it but it's worth checking.

Going back to the original question: how is the turbo actuated and what does the hose from the top of the pump to the turbo do/affect?

[MGP]

The turbo is spun using the exhaust gasses being pushed through the turbine, it's actuated by a valve in the exhaust turbine housing that allows exhaust gasses to bypass the turbine.
The hose that goes to the top of the pump is to send a pressure signal to the lda diaphragm, the lda is the part of the pump which adds extra fuel when the turbo is on boost, however the standard lda pin for the aaz is a straight cut pin as opposed to a pin with a ramp cut into it this is because the turbo on an aaz is there more for emissions control than power.
Fitting an lda pin from an sb or ra engine known as a gtd lda pin will give a noticeable increase in power.

Sent from my SM-G920F using Tapatalk

[Mark S]

This is great info, absolutely loving it. I had not heard of an LDA up to now but just did a little test. I took the pipe off the LDA and put a little plastic doggy-doo bag over the end while revving the engine. The bag inflated so there must be positive pressure in the manifold and the turbo is clearly giving some boost otherwise there would be a slight vacuum. Whether it is enough boost I suppose can only be determined by attaching a boost meter.

Then I attached a rubber tube to the LDA connection atop the pump, and blew into it as hard as poss. I could detect no change to the note of the engine but I wasn't sure if I was supposed to. Maybe I wasn't blowing hard enough or the change might be more subtle. But I've just had some work done on the pump so it is possible they cocked up the LDA, which might explain a loss in performance I noticed on the way home.

Changing the pin on the LDA: is a GTD pin easy to come by, is it a DIY or a workshop job, and does this mod require the fitting of an intercooler?

Many thanks.