Simple questions first...

1. If i pressurise the inlet via nipple on the UIM, with the intake hoses blocked...it should hold pressure right ?????

2. There are two hoses coming off the oil filler neck, one has the PCV valve attatched, where does the other go ????


Long explaination.....for those of a technical disposition or lots of spare time. My boost pattern is 8,7,5.


My intake tract doesn't hold pressure, but i can't feel or hear any leak. The second hose off the oil filler neck was pressurising the filler neck......i'm assuming this wouldn't happen in normal operation, as the hose comes from the intake and that wouldn't normally be under pressure.
i also heard a slight leak from the throttle body inlet elbow, a new 'o' ring fixed that.

Anyway, where is all the air going, running a line from a tyre at 40 psi, i can get about 4 psi max in the inlet as soon as i shut of the air the pressure drops to zero. Am i missing somethin'......if so just call me a dumb ***, but explain why !

I am at the stage; 'mazda engineers were on acid and i should have bought a damn supra'

 

I would think that there may be a number of things that could/should leak air. One major one is that the engine has overlap, so some of the air might be going out the exhaust.

-Max

 

On 92-94 cars, there are two lines to the oil filler neck, one from the UIM going through the PCV valve, and one from the primary turbo inlet pipe. From 95 on, the PCV was eliminated (and rightly so!).

I start with boost leaks before looking into the control system -- start with the turbos and work your way to the throttle body. You should physically remove all couplers and check them, a visual inspection isn't good enough. If you don't find anything, move on to the control system -- here is a good troubleshooting site:

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

 

thanks rynberg......for reply to earlier post also.

i have physically checked all the couplers and hoses.....had all of it apart and back together with new gaskets and clamps. Figured the best way to check for leaks was artificially pressurise the system. I have been through the test procedures for many of the components (BOV, CRV, check valves) , i think i am getting to UIM removal stage.....

So basically under normal operation that second hose to the filler wouldn't see pressure (i.e it plumbs in the intake before the turbo).

If the engine has some overlap it could be going out the exhaust. If i rotate it i should find a point it will hold pressure...i will give that a go soon and try one last road test before i take it apart properly...
....or burn it.