Varboy

I have reason to believe my actuator is screwed.

I am going to plum up the compressor boost signal directly to the actuator and measure the resulting boost, but in the meantime, should the actuator arm be able to move simply using my hand?

exvaux

iTrader: (1)

with a bit of force you should be able to move the actuator arm,could on mine.But mine is being rebuilt just now so not sure if that was related so im maybe not the best person to answer

saiklon

I can't move mine if holding it in my hand but can move it very easily if gripping it with pliers.

Slowboy Racing

I guess its down to how strong you are ? But you should feel a good resistance trying to open by hand.

What leads you to think the actuator is not operating correctly ?

Varboy

^^^It's just a suspicion at the moment.

To cut a long story short, I've reduced boost solenoid duty cycle on my AVCR unit down to 30% but I'm still achieving about 1.7 bar on 2nd on a TD05 (target is 1.45bar). I've checked all hoses, all seems to be ok (though I'm going to replace the hoses as a precaution).
So it's the solenoid (have cleaned this), could the be MAP sensor (but this reading hence it displaying the boost reading), the AVCR unit itself, or finally the actuator.

I'm trying to be systematic in my approach. It seems at the moment that there is absolutely no boost control coming from the wastegate itself, as boost rises so quickly and does not stop until the ECU activates fuel cut.

Slowboy Racing

If its only happening in second gear check the start duty setting for second and reduce if needed.

saiklon

Why don't you try connecting the compressor output directly to the wastegate as you had suggested? That will tell you whether or not your actuator is fine.

Varboy

It's happening in all gears except first, I just used 2nd as an illustration as it's usually quite difficult to hit huge boost in lower gears due to the comparitively lower load.

Varboy

Yes, when I get around to it, but if I can diagnose the problem without screwing around under the bonnet in this cold weather, then I will.

mcphilimey

this might help or may not, im not running a electronic boost controller but im having problems with my TD05 exceedind target boost pressure. I've used a compression tester for chainsaw's etc to pressurise the actuator and see if it was leaking. the arm moved fine and it held pressure. I tried fitting a manual boost controller and set it right down so it allowed very low pressure to start acting on the actuator, this reduced the rate at which the boost climbs i.e would not pass target boost until 6000rpm.
I have been told that it is very likely to be a boost leak from one of the control pipes coming of the turbo to the solenoid or from the soleniod to the actuator.
I'll keep you posted with what i find out

Varboy

cheers mate.

I've ordered new pipes from Subaru, which should arrive tomorrow. I'm going to swap these very pipes over to see if it helps.

mcphilimey

just put a peice of new silcone hose from my turbo nipple to the actuator and been for a drive. The car will only boost to about 0.5 bar as the turbo come in, but as the revs rise the boost starts to increase with the revs. does this suggest the actuator is faulty?

Varboy

The actuator operates the wastegate, as air pressure (increased boost) builds it will begin to activate the actuator and the wastegate will crack open. The pressure is set for the turbo (which in your case is 0.5 bar, that sounds normal).

However, I don't think you should be achieving much more boost that that as the wastegate is now open. (overboosting due to poor wastegate flow is a slightly different issue here ie boost creep).

My thought would be that the wastegate is not opening fully, which would of course point to a faulty actuator or the wastegate sticking slightly (which would again be due to a FUBARd actuator)

mcphilimey

when scoobyclinic put it on there rolling road they said it had a boost leak and that could cause this problem. i took the actuator rod off the wastegate and it's free. although i did notice that the wastegate had more travel left than the actuator rod was moving it.