Wastegate Actuator

[wallyman]

So i have been having an issue with fuel cut. I have fixed all my boost leaks. Replaced plugs and wires. I did a couple WOT pulls and im seeing 16 psi of boost before fuel cut. My only mod is a 3" exhaust. Im thinking waste gate actuator but im not sure. When i did my boost leak test i could move the actuator at 11-12 psi, but i dont know if its moving quick enough. I think the acutator might be too slow causeing my boost to creep up to 16 psi. Has anybody had a problem similar to this?

 

[kenamond]

So i have been having an issue with fuel cut. I have fixed all my boost leaks. Replaced plugs and wires. I did a couple WOT pulls and im seeing 16 psi of boost before fuel cut. My only mod is a 3" exhaust. Im thinking waste gate actuator but im not sure. When i did my boost leak test i could move the actuator at 11-12 psi, but i dont know if its moving quick enough. I think the acutator might be too slow causeing my boost to creep up to 16 psi. Has anybody had a problem similar to this?

I'm a 2g guy, so this might not apply to a 1g, but the 2g has a boost control solenoid which tells the wastegate when to open (at 10-12psi on a 2g). Perhaps yours is bad and is not sending pressure to the wastegate solenoid. Did you pull the vaccuum line off the compressor housing when you changed your exhaust (don't see why you would)? If so, did you put it back on correctly?

I'm not sure, but it might be creep as well, though I don't recall reading any threads about problems with the stock 1g turbo and creep. This usually becomes a problem when folks upgrade their exhaust and is a common problem with the EVOIII Big 16g. You can check for creep by disconnecting the wastegate actuator arm from the lever on the turbine housing. First, check that you can turn the lever freely by hand (with engine cool, please ) to make sure the flapper opens freely inside the housing. Then do a full-throttle pull this way. If you get more than a few psi boost, you have creep. If you get 17psi and hit fuel cut, you have bad creep. Your profile doesn't list an aftermarket boost gauge, but I don't know how you know you have 17psi boost without one. If you have one, update your profile, please. If you don't, you need one.

Hope this helps. Keep us posted.

 

[Akauf587]

Check the connections ont he BCS, i had the same problem so i just went out and got a MBC and that sorted it all out. Also check the vacuum lines are connected correctly.

 

[WillyC]

Forget the new BCS for now. It sounds like boost creep is most definitely your problem. Run your vacuum line directly from the pressure source into the wastegate actuator...no BCS. Now you said on boost tests it would open at 11-12psi so there's no reason it shouldn't when you drive the car. If your boost level goes up past the 11-12 point its definitely boost creep. Some options to fix it are: port the wastegate side of the o2 housing or make it a dump to atmosphere setup (if its not already), and the major fix would be to buy a 34mm wastegate flapper, cut your old one off, port the wastegate hole so its just smaller than the 34mm flapper and install the new 34mm flapper on the wastegate arm. Should be around $30 for a flapper and the old one can be removed with a cut-off wheel; new one installed with a hammer.

 

[CanadianTSi]

16psi shouldn't Fuel Cut.

Are you sure you fixed all your boost leaks?

Or you could always just turn down the boost.

 

[wallyman]

16psi shouldn't Fuel Cut.

Are you sure you fixed all your boost leaks?

Or you could always just turn down the boost.

Im pretty sure fuel cut can occur at 15psi, ill have to check.

 

[wallyman]

Forget the new BCS for now. It sounds like boost creep is most definitely your problem. Run your vacuum line directly from the pressure source into the wastegate actuator...no BCS. Now you said on boost tests it would open at 11-12psi so there's no reason it shouldn't when you drive the car. If your boost level goes up past the 11-12 point its definitely boost creep. Some options to fix it are: port the wastegate side of the o2 housing or make it a dump to atmosphere setup (if its not already), and the major fix would be to buy a 34mm wastegate flapper, cut your old one off, port the wastegate hole so its just smaller than the 34mm flapper and install the new 34mm flapper on the wastegate arm. Should be around $30 for a flapper and the old one can be removed with a cut-off wheel; new one installed with a hammer.

I had the overboosting issue before i installed the exhaust. Adding the exhaust could have made it worse.

 

[wallyman]

I'm a 2g guy, so this might not apply to a 1g, but the 2g has a boost control solenoid which tells the wastegate when to open (at 10-12psi on a 2g). Perhaps yours is bad and is not sending pressure to the wastegate solenoid. Did you pull the vaccuum line off the compressor housing when you changed your exhaust (don't see why you would)? If so, did you put it back on correctly?

I'm not sure, but it might be creep as well, though I don't recall reading any threads about problems with the stock 1g turbo and creep. This usually becomes a problem when folks upgrade their exhaust and is a common problem with the EVOIII Big 16g. You can check for creep by disconnecting the wastegate actuator arm from the lever on the turbine housing. First, check that you can turn the lever freely by hand (with engine cool, please ) to make sure the flapper opens freely inside the housing. Then do a full-throttle pull this way. If you get more than a few psi boost, you have creep. If you get 17psi and hit fuel cut, you have bad creep. Your profile doesn't list an aftermarket boost gauge, but I don't know how you know you have 17psi boost without one. If you have one, update your profile, please. If you don't, you need one.

Hope this helps. Keep us posted.

Well i have the factory data logger and i checked my boost solenoid. I could here it click over. That doesnt neccessarily mean it's working.

Yes i have an autometer boost gauge and egt.

 

[wallyman]

Thanks for your help guys. Im going to try and see if the acutator opens at 11 or 12 by bypassing the BCS. If that doesnt fix it im going to find a way to manually hold the actuator open to see if i have a boost creep issue.

 

[CanadianTSi]

Thanks for your help guys. Im going to try and see if the acutator opens at 11 or 12 by bypassing the BCS. If that doesnt fix it im going to find a way to manually hold the actuator open to see if i have a boost creep issue.

The actuator should open at around 9psi, run a pressure source straight to the wastegate actuator to test this.

 

[kenamond]

So you had this problem before the exhaust, and you were 100% stock at that point?

If that's the case, I agree with what WillyC said; connect a line from your compressor housing nipple to the wastegate actuator, but I'd also verify that the wastegate flapper turns freely by hand if you disconnect the actuator arm. Also, make sure the arm isn't hitting your lower heat shield.

With your boost line set up the way WillyC suggested and with a wastegate solenoid which opens at 11psi, you shouldn't see much over that on your boost gauge during a test run. If you do, I have no idea what's going on; you shouldn't be creeping on the stock setup.

If you still creep with the vac line run this way, I'd still try a pull with the arm disconnected from the wastegate flapper lever. If you see more than a few psi on that run and your flapper opens freely by hand, it's pretty much gotta be creep.