I have a 94 rx7 with greddy dp, high flow cat, catback, K&N airfilter. When I boost in second gear I get a solid 10-8 and then once I hit around 4.5k I get either 0 boost or 0-4 psi...It does this for 2nd, 3rd, and 4th once I get around 5k no boost...Just recently did a hose job, I checked over all the hoses this past weekend and they are all connected and no visible leaks however I don't have a vac/pressure tester (which I should probably get) I figured it would be a boost leak with the second turbo, but I can't find anything...could it possibly be the charge relief valve stuck open? I tried to take that thing off but it was stuck to the hose and I didn't feel like breaking it...any input would be appreciated.

 

Tough one. Suggest you go to the 3rd gen FAQ thread
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/faq-3rd-gen-other-useful-links-68640/
and go down to the T section (for turbo) where you'll find this link (and a few others):
http://www.autosportracetech.com/RX-...leshooting.htm

That should help you w/ troubleshooting and give you a plan to follow. The cause could be various things and you'll need to test.

 

I'd try a boost leak test. It's very easy to do and making a tester is simple.

 

Alright thanks, I had already found that link I was just wondering if anyone knew a common problem with the symptons I described. I'm assuming since the first turbo is boosting correctly I can just skip to the Secondary Turbocharger Leaks troubleshooting section.

 

Alright I used a hand vacuum pump and narrowed it down to the solenoid valve turbo precontrol, i'm assuming...one test the troubleshooting guide said to do was start your car and the actuator rod on the Charge Control Actuator will be pulled in, then they say to Stop the engine and remove the hose from Chamber A and the actuator rod will be out....however when my car idles, the rod is in...but when i turn my car off the rod comes out before I take the hose off...so i'm assuming the solenoid is stuck open.

When i tried to pull vacuum from the line going to the actuator, with the car off I couldn't.

So my question is, is there a solenoid i can swap with the turbo precontrol solenoid for a safe test?

 

Problem fixed...solution Charge control solenoid was sticking.

p.s. hand vacuum pump makes troubleshooting extremely easy...