Boost problems w/ tuner style

[DR. EVIL]

I've been throwing bad boost solenoid codes and have had trouble keeping a steady boost PSI. Before it would be usually around 17psi, but eventually creep up to 19psi after holding WOT for an extended period of time. I decided to hook up the turbo "tuner style". I ran a vacuum line straight from the wastegate to the outlet on the turbo.

Now when I floor it, I only get 10psi.... it will stay at 10psi for a short amount of time, then go up to 12... then higher.... I'm used to it going straight to max boost without that lag. I want to tighten the wastegate rod, but I'm afraid it will go to 15psi then creep up to 20 or something....

I have a Precision .63 exhaust housing and the TA-51, 3" THDP, and an adustable wastegate. I've been told that the TA-51 shouldn't have any problems with the hole the puck on the THDP covers....

Should I turn up the boost by tightening the wastegate? Think my wastegate may be going south? This doesn't have to do with the computer anymore so I don't know what to think

 

[DR. EVIL]

Also, I have a vacuum/boost gauge, what should my vacuum look like at idle and just rolling in drive?

 

[zam70]

car's a total piece of junk....bring it to me and i will dispose of it properly.

Could be the waste gate actuator...you're having the same problem (2 lb boost creep) with either setup. If you want, we can pull the actuator off my car and try it out on yours.

Let me know if you want to swap it. 529 9192

 

[DR. EVIL]

I'll just junk it you can have it for a big-mac and fries

It seems to be doing the same kind of creep now, but before it would boost normally up to 17psi, now it's only at 10psi.... that just could mean the rod's arm needs shortening....

I do still think that wastegate may be goin south.....

 

[sixgun86gn]

I also had this problem.Check this out....the wastegate solenoid is also wired into the brake switch.If you have a wg sol fuse that is popped,check the brake switch on the pedal.Mine did the same thing and I wiggled the brake switch and it stopped shorting the wg fuse.If you dont believe me check a GM service manual wiring diagram.

 

[DR. EVIL]

well, as long as I stick with tuner style, I'm not all that concerned if the solenoid works or not

The problem is that the humidity has been so bad last couple days that I can't tell if the boost has been kind of laggy due to the weather or something with the car....

I tightened the wastegate rod and got it up to 15psi now only took 6.5 turns to get a whole 5psi hell, maybe 3 more and I can get 17-18psi out of it

It doesn't seem to be creeping on me like it was before, just not boosting max as fast as before. When I get the boost up to 17-18psi, I'll know how it really feels. Man, I just want one nice un-humid night to test stuff out

I need to run some lines to the interior of the car and put a boost controller within arm's reach, kinda sick of getting next to the turbo and playing with my rod

 

[captrob]

Lag in boost

Going "Tuner-style"...with a line directly from the compressor to the actuator. As soon as you start to have possitive pressure(boost) the actuator starts to push the wastegate open, releasing some exhaust, and causing lag. The only way to keep the wastegate closed longer is to add spring pressure(shorten rod). Then you risk over boosting. It could be spring is a little weak, but that would not cause the creep. Sounds like the waste hole is too small and not allowing enough exhaust to bypass, causing a little extra boost.
What size is the wastegate hole? Larger than stock?
Hope this helps a little. Not an expert by any means!
CaptRob

 

[tim87tr]

Hey EVIL, you must have that PTS trans working good now, you've moved on to the next TR/$$ dilemma . I had the same problem a year ago when I installed the THDP. I just read something lately about how to port the wg hole, might find it in a search. I know that is one of the main problems from reading about it.

Or......I bought the MM BstC controller from Ramchargers ($159) on a recommendation from a board member. It works great and spools the turbo based on the TPS voltage. Works great for tuning on different octanes, or using alky, etc.