Actuator

After discovering that I'm only achieving 4 psi boost, I've decided to adjust the actuator. Turbo shields off, disengaged the actuator arm off the wastegate and I notice I have very little thread left to turn the actuator arm. I'll probably get a half turn but that's about it.

I've done this once before and wound the actuator inwards by a half turn - i.e. shortened the arm. Is this correct way to increase boost and not decrease it ?

Would have though if I've increased it once then why is still around 4 psi and not closer to 10

And roughly how much does a half turn equate to in psi ?

Half a turn = feck-all .All will be slightly different and it's a case of wind it in in a few turns and check .

You should have about an inch of thread left on a std actuator .Something is not right somewhere .Post a pic of what you got but sounds like the actuator is fecked .Get another .

[img][img]http://i297.photobucket.com/albums/mm226/pgoldsmith_photo/IMG_0647.jpg[/img][/img]

I've loosened off the nut and turned it as far as it will go to the right. I reckon I have one and half turns left to move the arm.

I'm now wondering if one of the hoses has a slight split and not one large enough for me to spot.

Turbo spools up nicely, but just doesn't boost that high any more.

I know it's a pain and a hose would be a lot easier fix but .......You need a new actuator You should have way more thread left than that and shouldn't be able to get it that short

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How easy is it for you to get the actuator arm on to the waste-gate peg? If it's real easy and not really working hard against the spring in the actuator canister, then it's cream crackered as Lee says. If it is hard to do so, then leave the actuator hose off the actuator, give it quick spin, watch the boost as it should shot up to the ecu boost cut; well that's if you have an unmodified ecu

Thanks, I guess after 20 years of use the spring is bound to get weak.

Well, as I have it all apart I suppose it would be best to change it before I put everything back together.
The manual mentions you can change it in situ - which is what Andrew told me. I presume the oil feed and return pipes need to be disconnected with new seals when refitted. Would the supplier of the new Actuator stock those or am I at the mercy of the Renault dealerships?

Also, the manual mentions about a special wrench to get to the oil return bolts, though they look like standard to me. Plus it goes on about topping up the turbocharger with oil after you've reconnected the lines and running on the starter for period. Is this all necessary? Or is this only applicable if you're taking the turbocharger off the car?

Are you replacing the whole turbo or just the actuator ? If the act then no need to disconnect anything apart from that ...Possibly the oil drain to get access to the actuator bracket bolts ...which if you do then you'll soon work out why they spec a special tool
Any turbo place will have the seals and actuator .You would be best to get one that bolts to the bracket or mod the old one once you have it off .Just makes life easier for future work .

How easy is it for you to get the actuator arm on to the waste-gate peg?

It's not that easy at all to reconnect, I use some grips to pivot against the oil return pipe to get it back on the waste gate. It takes a bit of effort to do so, which made me wonder if the spring is really that weak

Access to those bolts hold the Act on are not easy to see let alone get spanner on them. I'd like to know what technique people use if they don't remove the oil return - trade secret I guess

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Well if the spring is strong and holding the wastegate button firmly over the wastegate by-pass hole in the turbine housing, then if the turbo is spoiling you should be making boost. 4 psi is what you get if the actuator spring is weak or the flap is stuck open - which can't be the case as you are pulling the rod onto the peg. How far is the eye of the rod end to the peg, half a hole more?

Incidentally, when was the last time you changed your fuel filter? Need juice to make boost...

It's about 5mm from the centre of the hole to the centre of peg that it fits over. And as I said I need a pair of mole grips on the shaft to pull it over onto the peg, so it doesn't feel weak.

Fuel filter? Well, if I'm honest then not for some time. Would that really have the effect of loss of boost ?