Wastegate Actuator Problems

[ascenion24]

Car in question is a R33 GTS-T only mods are a front mount, CAI and a larger exhaust from the cat back (so I dont think it would really affect the back pressure)

So my car has been boosting to around 12psi no matter what setting I put the boost controller on... I removed the apexi boost controller and put a new hose with new hose clamps straight from the wastegate actuator to the intake piping. Car should be running 7 or 8 psi now like stock.

Anyways it still overboosts, I can hit 12psi in any gear if I plant it, im sure it would go more but the car starts to miss or backfire and starts acting all jerky.

Does anyone else have any ideas of anything else to check before I replace the wastegate solenoid?

[R31 POWER]

The vacuum nipple coming off the actuator, is it straight or on an angle?

[ascenion24]

Its an L shape. Comes off the side of the wastegate heading to the side of the car then it bends heading towards the front.

kind of looks like this one http://www.nissanparts.cc/catalog/nissan/R...SM%20NPLOGO.jpg

Edited March 9, 2010 by ascenion24

[R31 POWER]

Sounds like a RB25det one. I was thinking maybe it had a RB20 one fitted, hence the 11/12psi. Dunno man.

[ascenion24]

I cant for the life of me find a replacement actuator, all the generic ones have a straight pushrod and it wont clear the turbo outlet...

anyone got ideas?

Does the standard actuator pull apart so I can replace just the spring or do I have to replace the whole assembly?

Edited March 10, 2010 by ascenion24

[ascenion24]

I cant for the life of me find a replacement actuator, all the generic ones have a straight pushrod and it wont clear the turbo intake...

anyone got ideas?

Does the standard actuator pull apart so I can replace just the spring or do I have to replace the whole assembly?

Edited March 10, 2010 by ascenion24

[GTScotT]

test the actuator before you go any further.

has it always done this? or did it once upon a time work normal?

[ascenion24]

Has always done this since Ive had the car, which has been only a couple of weeks. I thought it was the boost controller not working properly so I removed the boost controller and it still over boosts.

I can move the actuator rod with a pair of pliers, But I dont know the limits of how much it should be able to move, it could be getting jammed and I dont even know.

Actually Ill move it by hand and measure the throw, then ill put compressed air to it and measure the throw. If the throw is less with the air then the actuator is stuffed. If the throw is the same then something is stopping the wastegate from opening completely and will probably need turbo out to inspect.

Am I on the right track here?

[ascenion24]

hmmm... just ran a test.

Hooked the air comp up to the wastegate and the rod moved the same amount that I can move it by hand. (If I grab the rod with pliers I cant move it I have to grab the connection at the turbo and twist, should it be easier to move?)

So it seems as if the swing valve is getting stuck, but its a stock system so I cant see anything being in the way.

I'm not sure what to do here, the test wasn't exactly scientific so not sure if I can rely on it.

What should I do?

Edited March 10, 2010 by ascenion24

[mosquitocoils]

Personally I'd try taking the c-clip off the actuator arm at the end where it kind of bolts onto the gate, then see if you can turn the little flap easily enough by hand, it should just be loose as anything.

Just to rule anything out at that spot.

[ascenion24]

Will give it a try tonight, how much should the wastegate move from closed position?

I drew a quick diagram to help explain, the diagram shows the lever in the closed position, should it be able to rotate only 45 to the vertical? or upto 90 degrees? etc...

Thanks.

[mosquitocoils]

Hey mate, going from memory I think it's more like this, but I could be wrong..... I didn't take much notice last time I had it off

Whether it's 90* or 135* I'm not sure, but it's definately in that area

Edited March 11, 2010 by mosquitocoils

[jjskyline79]

Sounds silly but have you checked to see if the Restrictor is still in this pipe????

If not get the tappered end of a bic biro and stick it in there that should stop it over boosting

Edited March 11, 2010 by jjskyline79

[ascenion24]

Restrictor what?

I've replaced the pipe with a new piece of fuel pipe to make sure there were no leaks.

So without the restrictor it would overboost?

Ill check the old pipe.

Also do you need the restrictor when using an aftermarket boost controller? When I had the apexi hooked up it was still over boosting.

Edited March 14, 2010 by ascenion24

[ascenion24]

Solved with another wastegate actuator

[32vspec2gtr]

If you want to run the higher boost, try gapping your plugs closer together. The standard coils can't deliver enough spark when there is higher boost so blows out the spark. If you reduce it to 8 mill gap if i remember correctly this should give you enough to run the higher boost.

Not the problem but hey