Broken Actuator?
 

I was boosting 4PSI so when i tightend the actuator to increase boost, the turbo takes forever Now im getting about 5PSI at 5K RPM. When i turn it back down the boost goes back to 4 but the wastegate rattles like hell. Is there any fix for this or do I just need a new one. Any place that sells Actuators? BTW I didnt turn the rod when i was tightening it, just the bolt.
Thanks, 7

Do you happen to have an air compressor? You can run some psi into it and see how it reacts. You should be spooling faster when you tighten the rod. When do you hit 4psi with it set back?

I'm still up for driving up after work and giving it a look over, or can you happen to come out on Saturday to the CDC Manassas event this weekend? Sorry I didn't show up at Fuddruckers on Sunday I went home and slept, the sun killed me.

Its normaly spools at 3500 RPM. If you could look it over that would be cool. Im trying to tune my BOV and i cant do it without any boost!

The $14.95 boost controller in this thread: http://forums.miataturbo.net/showthr...ost+controller may haelp with boost stability.

From your other symptoms suggest first checking the CAT. General symptoms would include slow/poor boost build, sluggish performance, and tendancy to overheat. If unsure how to run a vacuum test, suggest a few dead blows on the CAT and listening for any rattling. Not uncommon for the matrix inside to break into chunks, wedge in sideways and plug up exhaust flow.

Well I just spent the last 2 Hrs tuning and such on the road. From the stock poition of the bolt It was turned 3 full rotations tighter. This was as tight as it could go. It was makinbg 5PSI of boost at 5500 RPM. I then Loosened the actuator one full rotation. This would create 4PSI at 4K RPM. I then loosend it half a rotation more and it was boosting 3.5PSI at 3500 RPM and the wastegate rattle came back. I decided to leave it on the 4PSI setting for now until I can get a new actuator or look into the boost contoller option. Im now trying to tune the BOV and I need to loosen it but im not sure how loose I can go without breaking the diaphram inside. I have a GReddy type RS. Does nyone know if something would stop the it from looseing too much or if it will just break? how do i know when its on the loosest setting?
Thanks,
7

I dont think its the CAT because I just changed the exhaust not more then 2000 miles ago and the CAT was clean then. It couldnt have just broken the moment i decided to turn up the boost.

I have the Greddy Type-S BOV and I removed one of the springs on the inside and I was running it at full soft with the screw adjustment acutally removed. It sould still give me flutter under light loads blowing off. Since I've gone recirc. I've had no flutter. I think they are almost the same design, so the farther out you have the adjustment screw the softer the valve.

If I can meet up I can throw my mbc on it to see if your boost rises faster and holds better, which it should. I may be able to dirve up tonight. PM your cell.

I need to work tonight but tomorrow would be great. Ill send you my #

Cool, we can meet tomorrow for sure. We'll see how it reacts with my MBC.

One way to check your actuator:

Do this cold, unless you have restaurant fingers:)
Remove the vac hose to the actuator
Remove the wastegate clip and unfasten the end
"Gently" (it may take some force) push the rod into the actuator housing.
Place your finger over the vac nipple
release the rod pressure
remove your finger,
if the can held vac you'll hear a small sucking noise.--Good
No vac - Bad

This doesn't check the spring, but ensures that your diaphram is intact, takes thirty seconds to perform and is free...

You should be able to use any actuator that can be adjusted to you desired boost. One off a T3 would work, but you might have to fab up a bracket?
IIRC I saw a pic one (Honda?) using a dog chain, and a spring, mounted it to the actuator on the engine block, damnest ingenuity ever...

Hi,
I tried this actuator check tonight as I have not been able to control the boost on my T25. I found that I could not push the rod in to the actuator housing at all. I could pull it out, against the spring. I'm a newbie when it comes to wastegates, and am wondering what my symptoms mean?
Thanks
J