Hi, I have this issue with my primary turbo. Sometimes I will boost with no problems to 10 psi, (all test runs done in third gear) then after the 3rd or 4th test run the exhaust tone changes and I only get about 5 psi max.

I let go off the throttle and try again still 5psi and exhaust tone is totally different seem louder.

I’m thinking my turbo control solenoid is the problem, what do you guys think?

Thx a lot

Stock FD downpipe, viton check valves, silicone hoses,sequential turbo.

 

any ideas...

 

Try looking at this site first:

http://www.fd3s.net/boost_problems.html
and
http://www.autosportracetech.com/RX-7/rx7stuff.htm


I have a very similar problem. Intermittently the primary turbo does not spool assoc with change in exhaust tone. I am in the process of tracking down the problem and and have found so far that when it does into this "mode" the turbo control actuator is half retracted when it should not. You can see this part under the car without jacking it up. will be checking TC solenoid and check valves next. Noticed ur in the DC area too whereabouts?

 

yep today I changed all the check valves with viton ones, didn't fixed anything still get inconsistent with primary boost sometimes. I read that TC actuator don't usually go bad so it might be the Turbo Control solenoid. Next thing I will do is test the TC solenoid, It will take awhile to get in there tho. I'm around arlington a bridge away from DC.
Tell me what you find.

THX

 

I check my Turbo control solenoid today, gave it some power and it didnt even click.
I replaced it with a used one i had, now i still get 6 psi on PRIMARY sometimes, and my transition is low 10-6-11 so replacing the solenoid didnt help, i checked the solenoid rack all properly routed,check pressure chamber holds 10+psi, along with vacuum chamber holds vac. replaced all check valves with Dale clark ones, no boost leaks. I Will be replacing tomorrow the pre-control and wastegate solenoids.

Any else got something I should look out for.

 

Well today I switched pre-control and wastegate solenoids, still no fix. After putting the car back together (solenoid rack and UIM,etc) I noticed a loud blowing wind like noise when secondary comes online, but my boost is 11 psi after transition. I wonder why its loud I can hear it in the cabin really loud blowing sound but no boost loss weird. Any thoughts?

 

Have you checked the main hose leading to your BOV, as well as the small hoses leading from the primary turbo to your CCV and BOV actuators? Just because you're still boosting 11 psi after transition doesn't mean you don't have a leak. The system will compensate for the leak if it's not that big, meaning your turbos will just work harder.

 

Main hose leading to my BOV is ok as well as Y pipe to BOV (new hoses). Small hose all routed properly BOV as well as CCV. "Just because you're still boosting 11 psi after transition doesn't mean you don't have a leak." Which system will it make it compensate? What about my 10-6-11 any ideas?

 

Your stock turbo system can't tell the difference whether there is a leak or not. It just tries to keep the boost pressure at the preset psi setting. If the leak is small, it just forces the turbos to work harder to obtain that pressure.

At this point, I would start checking the operation of your pre-control actuator, since you're getting inconsistent primary boost.

 

If you still have your pre-cat, which your thread indicates you do, the catalyst in the pre-cat may have broken loose and is shifting around. This could block up the exhaust and definitely affect the ability of the primary turbo to spool-up properly on repeat boosts. Even if it has not broken loose, do as everyone should do, get rid of that pre-cat.

 

I meant stock FD, downpipe(pettit). Ok I will get 4 new turbo solenoids and check again then I will check pre-control actuator. I will update when I get the parts(few weeks) Thanks Alot.

 

But I am having the EXACT problem... Was the cause ever found?

I have no secondary boost before. And went into shop and replaced one of the solenoids. And now I am occasionally getting primary boost but no more after if I transitioned to secondary after a run. After driving for a long while, primary boost may come back. And its driving me insane.. seems like my car is haunted.