Well allot of times I tell myself these things wouldnt be as much fun if you didnt have to fix them every once in a while but come on...

Ok so a few times now ive been drivin and all of a sudden ill notice the tone of the car get real deep and allot louder, at which point I notice that my primary turbo is not spooling at all, I step on it & no turbo spool my boost gauge will just sit right at 0psi & as the revs climb like it was born an n/a it will open secondary turbo just perfectly...But when the pri turbo is spooling its working perfect, my transition is perfect, everything is perfect.
What would cause this?
Im thinking kinked vacuum hose but im not sure...
Anyone been here before ?

 

kinked vacuum hose or a dry-rotted one. Maybe check the wastegate actuators.

 

Check the vacuum hoses in front of the UIM

 

yea i know, I just redid with silicon hoses and sequential simplification but I think there is one hose that might be kinked a little too much, Ill have to dig around, anymore suggestions are much appreciated

 

Well I think I may have found it but its hard to say cuz it only happens sumtimes...
Anyway while I was under there I noticed I was alittle low on blinker fluid so I filled that up too...
JDub

 

Twin - did you actually find the cause for this? I'm having the exact same problem. At first, it only happened about once a month, so I wasn't too concerned. Now it happens a lot more frequently, and it is quite annoying...

I thought that I had narrowed the problem down to either the vacuum or pressure side of the TCA not operating correctly, but I'm not sure.

What did you figure out?

Thanks,
Rob

 

I have the same problem as well. I know I have a problem with the TCA already because with KOKO it doesn't pull the TCA in.

As for it fixing the problem listed above, I'm not sure but any help from you guys would be useful. Thanks!

 

did you guy fix your problem? I'm also having the same problem too, maybe we probably switch some hose around for the TCA......

 

I'm going to try using my EGR solenoid for the pressure side TCA solenoid since I disabled my EGR valve.

I think the vacuum side is okay because I could manually trigger it and it pulls in the TCA.

I'll let you guys know if this solves the problem. I'm also going to change all 4 of the plastic check valves with McMaster #47245K32.

 

mor - great ideas. Let us know how it turns out.

Quick question though: how did you manually trigger the vacuum side? I'm pretty sure that one of the 2 solenoids that controls the TCA is the culprit on my car, but I can't figure out which one by mental logic. I'd have to hook a boost guage up to both the pressure and vacuum side to actually figure it out. What a pain... maybe I'll just replace both of them and not worry about it anymore.

I don't know if it helps, but I know that all of my check valves are working properly because I replaced them a few thousand miles ago, and just recently checked them again when I was under the hood.

 

The TCA solenoid that controls vacuum is not on the rack. It's behind the wastegate/pre-control solenoid pair and if you take off the pair you could actually reach the connector on the TCA solenoid.

Then just start your car...rev it to build vacuum...then apply power and ground to the solenoid (disconnect connector first) and it should click and the TCA should pull in.

I can't reach the on on the rack (pressure side) so I'm just gonna guess it's the problem and try the EGR solenoid in its place and hopefully it'll work.

We'll see. Good luck you guys!

 

AT a time that you have no boost in the primary try raising the car and manually moving the pre-control arm with a pair of pliers. Mine was stuck in and I pulled it out and I had boost for about one or two runs. Then it stuck again. In my case I needed a new Turbo Precontrol Actuator (about $450 for the part). Good luck.

 

matwey - good idea. Unfortunately, with my car this won't work. Once the system switches to secondary boost, it doesn't switch back right away, and I'll loose primary boost. But, once I loose my primary boost, it will come back on within 2 or 3 minutes. In otherwords, I loose primary, but only temporarily before it (slowly) switches itself back to primary mode.

Basically, theres no way that I can stop the car and jack it up quick enough to crawl under the car and find the cluprit...

If I want to track this down, I'm gonna have to use my boost gauge to tap into the various pressure/vacuum lines and see whats going on...

Although, I may be able to stick a camera under the car to check things out

 

I just check under my car for the pre-control arm to move while WOT in idle, but nothing... However my TCA arm did moved.. Does this mean the mine pre-control actuator is bad? cause I thought that the arm is suppose to pull while wot???

 

Mine only happens after going WOT and full boost, but then I drive nice and easy for a few minutes and it will come back online, Ive narrowed it down to 2 vacuum hoses, they are 2 of the 4 that stick straight up and sit just to the left of the alternator, Im sure they are the precontrol solenoid avc hoses and it seems they colapse from too much pressure caused at WOT. Im going to try putting some thicker/stronger hose on those 2 pretty soon and see what happens...

 

If not that Im going to replace the solenoids connected to those hoses and see, I am near positive this is my problem