Hey guys,

I just ordered 4 McMaster check valves and changed the two in front of the UIM and the one under the pressure chamber.

There's one more I have to change but I just wanted to know what it's for. The one I'm talking about is by the firewall and comes off one of last pipes on the solenoid rack. It attaches to the back of the UIM. What does this check valve control?

I'm trying to fix a TCA problem and believed that the front check valves were more important but the problem still exists, basically the TCA only glitches when KOKO. If I manually apply power to the TCS (vacuum side) it will pull in.

Another question, on KOKO what does the ECU do to make the TCA pull in. Does it control the vacuum side TCS or pressure side TCS on the rack? We used a tester to check the signal from the ECU to the vacuum TCS and it kind of pulsates but when I give it full power manually it pulls the TCA in. Do you think I have a short in my harness?

Anyways, sorry for rambling. Please help, thanks!

 

Anyone?

 

I believe that is for the solenoid that controls the acv.

 

I can't remember since i removed my Double throttle, but i think it's used for Double Throttle acuator. If it's not that one, then there is one more underneeth the manifold, not sure what it does though sorry i couldn't be of big help.

 

It IS the vaccum chamber check valve. Check out RobRobinette's web site or autosportracetech for troubleshooting problems. Thats the vaccum chamber check valve. If it is bad it will cause a leak in the vaccum system which in turn will cause the TC and CCA not to work properly when performing the KOKO test. Good luck it sounds like that might be your boost issue culprit. ACV CHECK VALVE Haha!! J/k

 

Great replies!

I'm so hoping its the vacuum chamber check valve. I know I got the pressure chamber one fixed and the other two on the front of the UIM.

If this is in fact the vacuum chamber one then I believe it should work because all the other three check valves I changed were really hard to blow through.

I'll change it and let you guys know. If this isn't the solution, what else do you think can be causing the TCA problem? Solenoids? Short in harness? Hopefully not, thanks again!

 

Have you done the vaccum hoses yet? If the hoses are old and brittle it may be a possibility that there is a leak in one of those. Also there is the solenoids. possibly a hose hooked up incorrectly? Without starting a new thtead here,... what was your boost situaion prior to the check valves getting done?

 

Well maybe I am reading this wrong but I marked what I thought he was talking about in yellow. See the attached pic.

The pic didn't turn out as good as I expected but you can look here:

http://www.scuderiaciriani.com/rx7/v...placement.html

Just follow the dark yellow hoses. Goes from the UIM to solenoid "C" and then to the acv. Maybe I am missing something but that is how it looks to me.

 

ummmm pressure sensor?

 

Ok. So it is part of the acv though?

 

arutha,

Thanks for the pic. Actually...when I follow it it goes to the Turbo Control solenoid (vacuum side). I sure hope this is it.