Just got a boost gauge rigged into my 93. I knew for a fact i had a boost problem, and i confirmed it tonite. Did the test, boost held at 5psi steady from 35 in 3rd till redline, then hard shift to 4th and boost dropped to 2psi and stayed there. would build 5psi if i let off and got back on it. Same pattern regardless of gear. At idle, pulling 18in hg. Any ideas?`

car is stock besides 3" dp and 3" catback

 

Any ideas? Yeah, you have some boost leaks. Get out there and start going through the system, starting with the path from the turbos to the throttle body. You have to actually remove the couplers and carefully check them for splits.

Your second problem (2 psi, let off, 5 psi) indicates a problem with the vacuum chamber or the lines leading to/from it. There is a check valve in one of those lines that likes to go bad.

Start troubleshooting: http://www.autosportracetech.com/RX-7/rx7stuff.htm

 

ok sounds good. i already recieved all 4 new check valves and all the silicone hoses are on there way. ill check the couplers tomorrow and order those if need be.

 

But boost leaks can also cause these kind of symptoms. I suggest you proceed by first chasing out all the boost leaks, then if you still get inconsistent boost look at the check valve.

But if you're like me and you want to be thorough, you can test the check valves too while you're in there.

Dave

 

Good point, Dave. Definitely needs to find the primary leak before proceding with steps 2-37.

 

so it definatly seems like a leak and not a bad solenoid? like i said, i have all new check valves and the silicone line will be here monday. maybe when i do the lines, ill just change all the couplers to silicone with t clamps

 

The primary needs to make like 8 or more lbs before it will even begin the switch to the secondary. Check all your couplers, dont just look at them, pull them off and bend them some to see any signs of cracking. First look at the coupler at the end of the Y-pipe, if thats not it then check the ones around the intercooler. This should be a pretty easy fix, no need to mess with the turbo control system first.