Thread: Td5 turbo boost modulator fine - what about wastegate actuator?

What type of exhaust flex does it have? The bellows type has an internal restriction of about 40% that the earlier wire mesh ones don't have. Mine revved much more smoothly with the bellows replaced with a wire one.

Edit: If the actuator doesn't open then its not the problem. It wil only be a problem if it opens prematurely, ie rod too short. Make sure that you can move the wastegate and that its not stuck partly open.

Edit: should read "rod too long"

it's a 99 so it's got the wire flex joint

hopefully the answer is the wastegate adjustment (i.e. rod too short so overboosting) or stickiness, so I'll have another play with that...

Originally Posted by feraldisco

it's a 99 so it's got the wire flex joint

hopefully the answer is the wastegate adjustment (i.e. rod too short so overboosting) or stickiness, so I'll have another play with that...

Yeah, got to get that the right way! The shorter the rod, the higher pressure req'd to open the wastegate with the possibility of having too much boost but only if the ecu objects and cuts fuel (which makes the engine jerky, not underpowered). Rod too long and the wastegate will open prematurely, thus not allowing the engine to produce the normal amount of torque.

wastegate was a bit sticky, but even after freeing this up there was no difference in performance. Have been playing around with wastegate rod length - even though Tombie reckons to go no more than half a turn at a time, I assume there's no way you can stuff the motor doing larger adjustments - presumably if the rod is too short, the ECU will handle any overboost problem and if too long, you'll just be down on torque?

BTW, I'm curious to know if I'm in the right ballpark re rod length - I started off with 11 exposed threads between locknut and actuator? I realise it's not a very scientific way to compare, but I don't have a boost gauge! I recall a rule of thumb of adjusting until wastegate is fully closed with engine off - does that require shortening the rod until it gets too tight to move the adjustment nut further?

Finally - how much difference should I expect with a disconnected MAF - there was a slight difference in the way the vehicle ran but not huge, so maybe the MAF is faulty after all?

Despite what you have been told, I think the MAF is to blame. The best method is to try a known working example. Also, the oil in harness issue can also effect the signal from MAF and AAT in the airbox lid by insulating the signal from either of these. The MAF may not be recording a fault, but the figures from it should read from 550 to 650 Kg/Hr at flat throttle, and at idle at least 55 to 65 kg/hr. These figures are obtainable with machinery like Rovacom etc, but I am not certain that Testbook will actually give real time readouts? Can someone who has used it tell me?
So, if you are seeing only 400 or so Kg/Hr airflow at flat throttle, there is the problem.

JC

I was hoping that wasn't the case as they're about $3-400? But yes, the simplest way to test would be to do a swap with a known working example - any volunteers with Td5 Discos in ACT region? Otherwise I'll have to go back to a LR specialist in Sydney who can do the correct testing.

One of the reasons I've never really suspected the MAF is because cleaning it previously made a noticeable difference to smoothness, so I assumed it was working, but maybe not as well as it should be...