SpeedracerRX7

Ok for those of you that like to call the search route, don't waste your time. Here is some of what I have referenced to no avail: http://www.autosportracetech.com/RX-7/rx7stuff.htm another: https://www.rx7club.com/forum/showth...low+transition another: https://www.rx7club.com/forum/showth...low+transition

I have referenced many others as well. I have had many of these problems in the past but none of my previous solutions panned out nor any of the ones on the pages listed above.

Now down to the meat of the issue. I have a similar setup to what Damian posted here: https://www.rx7club.com/forum/showth...ost+controller The only difference is that I have a Profec B on the wastegate actuator. What happens is that the primarys spool and I get good boost but there is a moan or whistle the entire time its under boost. Where the transition is supposed to kick in I only get around .4 or so of boost all the way to red line. If I shift and jump back on it the secondary turbo kicks in and pulls hard.

I have checked and changed out a bad turbo control solenoid, the one on the LIM. I have tested the other turbo control solenoid (third back in the rats nest). Now they both worked with it cold but I can't vouch for them w/heat in them. I am getting my hands on a Mighty vac tomorrow to test the actual actuator but I can't see it being that if it actually transitions as soon as I shift.

I thought the whistling might be the CRV staying opened so I pulled it and checked it and it checks out fine. What does the solenid C in the vacuum diagram that is labeled "Switching" do? If there is anything I am missing please let me know. Thanks for your time!

P.S.--> I have one more track event before I'm switching to a Single so please help me to enjoy it w/boost.

the_saint

waiting for answers

Mahjik

iTrader: (1)

If you have secondary boost, then your CRV is fine.

Start with the Charge Control system. If this is failing, it will allow your primary boost to vent through the secondary until the CRV closes (thus giving no primary boost but good secondary).

SpeedracerRX7

Ok here is an update on my troubleshooting. My track day is this weekend so I'm kinda panicing. As I said I have primary boost and I have secondary boost but no transition under full throttle. It either takes me shifting gears at a high RPM or if I kinda lift around 4500 RPM I can get it to transition. If you look at the boost controller setup that I have posted above you can see that I have a manual boost controller on the pre-control side of the setup. I found out yesterday while bedding in my track brakes that the more I open up this valve the more I get a high pitch squeal from somewhere on the pasenger side of the engine bay starting at around 2700 RPM. I am at a loss to figure out what is leaking, venting, or whatever it is doing. As the sound gets louder the more I turn that valve it leads me to think that it is somehow dumping the prespool boost that is building in the secondary turbo and therefore when it is time for transition the car sees that none is built up and won'd do it. Any help would be greatly appreciated as I would like the car fully functioning this weekend if I could.

dgeesaman

iTrader: (7)

Do you have your mityvac yet?

dgeesaman

iTrader: (7)

Generally, when a shift fixes things, it's because the vacuum system is leaking and the shift recharges the system with vacuum. Start with the check valve, and if that's good, use the Mityvac to test each solenoid for leakage.

Dave

adam c

iTrader: (2)

If you believe the prespool line to be the problem, replace it. Putting in the old line (with the pill) should give you solid transition at 8psi. By replacing it, you will at least know if that is the problem.

I also suggest that you replace all of the check valves, unless they have been replaced recently.

SpeedracerRX7

The check valves would make sense. I hope I can find some to replace the ones I want with in time. I doubt I can but at least I have something else to check now. Anyone know of a generic (Autozone or something) check valve I can buy to replace the ones that I have?

tphan

is the sound like hissing? smell any gas afterward?

Well...my FD is doing something similar...after reading about the one way check valves and how they work for the Pressure and Vaccumm chambers and how these affect boost...I am pretty sure the Green/White checkvalve on my FD are fried...they are 50K miles old.

Just order two from Mazda dealer they are $30.05 each...ouch! Oh part no. is

N390-13-995A