Jump to content
The mkiv Supra Owners Club

Boost issue. Please help.


Guest jtt97

Recommended Posts

Guest jtt97

whats up? I've had a boost issue for awhile, been trying to solve. 97 TT BPU 6 spd. Blitz sbc--id electronic boost controller. I used to hit 18 pounds boost no problem. Now it wouln't go above 15 pounds.

 

Boost controller settings:

 

boost- 65%

gain- 14

AC/WG - AC

Auto/Man - Manual

 

1)Checked all VSV's.

2)EBV VSV was bad. now replaced. Still only 15 pounds

3)checked all actuators.

4)EBV actuator should open at 14.2 psi takes almost 30 psi before it will open.

5)wastegate actuator opens at 17.4 but seems really stiff and slow to open.

6)I did the TTC mod (blackwell electric switch)now only can get 10 pounds of boost at 4000rpm.

7) back to sequential mode now 15 pounds.

 

What could be the problem still? EBV actuator? wastegate actuator? pressure tank maybe? I was not able to test that out yet.

 

I'm at a loss at this point any advise please help.

 

Thanks.

Link to comment
Share on other sites

Guest jtt97

I have an HKS SS welded to aluminum inner cooler pipes. I left the stock BOV installed just removed the vacuume line that goes to it so that it would not be opening and re routed that line to the HKS bov. Should I remove the stock BOV and cap off both sides?

Link to comment
Share on other sites

Guest jtt97

I will definetelly remove the stock BOV just to eliminate 1 potential problem. I'm not sure how a boost leak at the BOV would cause switching to TTC mode would drop the boost from 15 down to 10 pounds.

 

I'm also thinking about just replacing all the vacuume lines just to rule any kind of leak out. This is cheap so it 'll be the first thing I do.

 

I'm also wondering if any of the vacumme lines are reversed on any of the VSV or actuators. All the lines are correctly routed to the proper units but maybe reversed. Could this cause the problem I'm having?

 

Thanks for your help so far. wish me luck.

Link to comment
Share on other sites

Guest jtt97

Well, this has finally been resolved car is boosting great. Hit 19 pounds no problem. Had to actually turn the boost controller down and the car feels like a new car again.

 

The problem ended up being the factory bov. I had put on an HKS welded to the intercooler pipes and left the factory on in place just removed the vacuume line to it. I removed it and the hoses were so brittle they cracked and torn apart so that was probably where some boost was seeping out. Capped the two pipes that went to the factory BOV and everything is great. Thanks for your help. I wasn't even looking at that as the problem. It would have taken me alot long to figure that out.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. You might also be interested in our Guidelines, Privacy Policy and Terms of Use.