i have a 1993 fd the only mod is hks cat back. i got her back from the shop put the full 2000 miles before boosting and now that i can, there is an issue. 3rd gear pull from 35mph 10psi then when time comes for the second turbo to kick in she drops down to 5psi and once she gets to 6k rpms the boost bounces from 5 to 7 psi wtf is up.... any help is appreciated thanks

evan

 

what shop?

 

lucky 7 racing

 

So, you are basically getting a 10-5-5 to 7 pattern.

A quick check you can do is the following:

Remove the black pressure chamber at the front of the UIM and look at the two solenoids that are right behind it. The left is turbo precontrol, the right one is wastegate control. The harness plug with the white tape on it should go to the right one.

If they are reversed (which I have seen happen) you will get a boost pattern very similar to yours (usually 10-5-6).

 

cool, i hope thats what it is. i will check that once i get home from work tomorrow, will let u know what happends

 

i gave it a shot but no change, anything else that can cause this

 

Check the link to the turbo system in this thread
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/faq-3rd-gen-other-useful-links-68640/

I'm also troubleshooting a boost issue at transition to the 2nd turbo.

 

+1 on gracer7-rx7's recommendation

Specifically, have your installer go over the turbo control solenoids, hose routing and check valves. You can eliminate the wastegate and pre control solenoids out of the equation by installing a boost controller, like a Greddy Profec-B Spec II. You can diagnose a lot of these types of problems by T-ing into some of the vacuum lines at specific locations to check for pressure and vacuum under varying RPM and manifold pressure conditions.

Check this out: http://se3p.com/index.php?title=FD3S...s.2C_and_Tanks

 

thanks for the links hopefully i can figure it out.

 

I gave up on my solenoids working properly and just bought two halman pro rx manual boost controllers, The transistion is smoother, boost builds quicker and its overall a much simpler design, Perfect 10-8-10 pattern with both solenoids unplugged and capped.

 

what dose that setup consist of, just t-ing into vac lines and blocking off solenoids?

 

https://www.rx7club.com/3rd-gen-archives-73/my-boost-control-setup-perfect-10-8-10-pattern-178136/

Same setup I used.

 

dude thanks for the link to the right-up super good info

 

ok so im super amped i just fixed my boost issue like 5 min. ago. i went over my vac-lines one last time and i found one that had collapsed, swapped it out and bam 10-8-10. thank u guys for all the help u guys r the ****!
evan