kevincnc

Just when I thought everythng was great.. AFR is still good (11.7 at 10 PSI,) and I was getting 15 PSI boost yesterday, now it only gets 10 with the Profec Type S turned all the way up. AFR at idle is only about 13 now also. Vacuum leak? My tial wastegate is only a few years old.

Another thing that I though was strange is that I could only get 15 PSI after recently installing the new 3" exhaust with my Vitesse Stage 2 turbo. I don't think I have an exhaust leak, but maybe that's it?

refresh951

How do you have the WG plumbed? Dual Port? Single Port? How do you have the solenoid plumbed? I had a Profec and it was not straight forward to program.

kevincnc

Dual Port. The Type S isn't programmable, it just has a high and low ****, and a button to switch between the two. Neither one gets it over 10 PSI now. I didn't mess with the WG plumbing when I did the exhaust, and it was working great until today. Everything else seems normal, I'm stumped

The only thing I can figure is that the WG is stuck partially open. Any ideas that don't require me to remove it would be great! It's been so long I really don't even remember how it all works. I feel like a novice again.

fejjj

Check all your IC, TB and Turbo connections. You may be loosing boost there especially if you are still using stock rubber couplers.

refresh951

10 psi would generally mean you are just running spring pressure.

kevincnc

Thanks guys, I don't see any leaks, and the lines at the WG look good. Looking back at an old thread when I installed it makes me think the valve isn't working since it should fail safe- https://rennlist.com/forums/924-931-...ictures-7.html

I guess I'll make sure it's getting power first, but I'm not looking forward to removing the intake again to get to the valve if it's bad. Waaa.

kevincnc

Okay I unplugged the solenoid right at the Profec connector last night, and could clearly hear the valve clicking when I gave it 12 volts. The Profec lights up when the key is on, but it's not sending power to the valve. Is that right? I didn't try it with the car actually running. Shouldn't it be on until boost reaches the setpoint, and then cycle off/on to regulate the boost?

I don't know what the next troubleshooting step should be.

Maybe the valve is stuck, but the coil is still good?

Should I just put power to the solenoid manually and (carefully) see if I get over 10 PSI?

kevincnc

I powered the valve manually, drove it, and still only get 10 PSI. Other than the low boost, everything feels and sounds perfect. Any suggestions would be great, even if they are to remove the intake and check the valve, or remove the wastegate and check it. Any other easier solutions woud be awesome.
Kevin

refresh951

I would read this and get a clear picture of how an EBC works:

http://blogperrinperformance.com/boo...lained-part-2/

I would hook up a MBC and see if you can control boost. My guess is that the issue is with plumbing or the EBC and not the wastegate.

kevincnc

Thanks Shawn. It has worked well for years, it's just been so long since i did it, I forgot how it's plumbed. Unfortunately I put the solenoid under the intake, so can't remove any lines to check things out easily. I have an MBC or two that I can hook up, just don't want to remove the intake if I don't have to. I guess this is a good time for a refresher and I'll have to hook up something temporary.

Rob in Oz

Shawn

Thanks for the link - a nice clear explanation of the various boost control methods.

Rob

Teddy952

I've had similar issues recently controlling boost. I was only seeing 10psi and as Refresh pointed out, that is the spring pressure on my Tial WG. I didn't want to start searching for exhaust or vacuum leaks before verifying that the WG worked at all. I changed the hose routing so that only the boost pressure was plumbed into the top port of my WG. I left the side port open to atmosphere.

Please be aware that this configuration will not allow the WG to open and you WILL over boost the engine if you are not careful. This was done as a quick test to verify that the WG will hold pressure over 10psi. I kept a close eye on the boost gauge while I went for a short drive. Once the gauge went to 11 or 12psi I knew the WG was fine and that the plumbing or solenoid were next on the list to check.

gpr8er

Had the same issue. Turned out that the solenoid valve was bad. I didn't have a brass filter on the open port and ruined it. Replaced it with a MAC valve for cheap!

kevincnc

That was going to be my next try.

Could you still hear the valve clickinmg even though it didn't switch? I have a vent on the open port on the valve.

Thanks for the help.

Kevin

kevincnc

Okay the valve is fine, and I can easily blow into the top of the wastegate. That would mean the diaphram is bad, and it's pretty easily replaceable, correct? I can't find any info on replacing it.