I have this posted in another section but i thought Id ask a little closer to home,
I live in calgary and I bought a 93 jdm rx7 efini and it would boost to .05 bar and them bog and jolt the car pretty hard, at first it was only under heavy load, then one day i started it up and it would boost fine almost to a full bar, I pulled the car out of storage a couple weeks ago and its doing the same thing. I thought it might be fuel cut but the check engine light doesnt come on and it will allow me to rev as high as I like (I have no experiance with rotary cars, Ive owned turbo'd toyotas all my life) I cant see it being any different between brands as far as fuel cut is concerned. so my next guess was bad by-pass valves I pulled the vacuum lines off and blocked them off but it still does the same thing. I took the car to Rx7 specialist here in calgary they fixed the Y-pipe coupler and adjusted on of the intercooler couplers aswell as replaced the res mid pipe. it ran great for 2 day then started doing the same thing.. 0.5 bar of boost and it just falls on her face. rx7 specialists solustion was install a PFC and hope that fixes the problem... I honestly have no idea what it could be. so I turn to the experts on this site.. if anyone has any ideas on what it could be please let me know. I really appreciate it! as far as i know the engine is stock just a re-amemiya intercooler. other then that it looks pretty stock.

http://www.youtube.com/watch?v=f2VwY9yha1s

 

If it ran fine for 2 days after they fixed it, wouldn't you assume its the same problem :P.

Bad bypass valves? You blocked them off? huh?

thewird

 

too long, didnt read.

cool name, habibti :P

 

1. Are you still running sequentially?
Assuming you are,

2. Can you describe your boost pattern in 4th gear? Are you getting 7-7-7? (0.5 bar = 7psi).

Assuming you are, 7psi is what the car will run on only the stock wastegate without the factory boost control in operation.
So, things to check would be the lines from the actuators to the wastegate and turbo precontrol solenoids, or the solenoids themselves. They are found at the front of your upper intake under the pressure tank.

Your best friend right now is this website: http://autosportracetech.com/RX-7/Tu...leshooting.htm

 

Does the car have a boost controller?

thewird

 

that is a bit easier to read...


we need a few more questions answered before we can help you out much further..


Questions...

are you running a boost controller...
are you still running your turbos sequentially
Can you describe your boost pattern in 4th gear? Are you getting 7-7-7? (0.5 bar = 7psi).



J.

 

Got an idea. Does it work fine under partial throttle? Without going into WOT.

thewird

 

Sometimes this is the cause of sudden boost problems:

There are little clips which hold the actuator rod ends onto the actuator arm pins. The wastegate and precontrol actuator rods are visible from the top and if any of the rod ends came off the pins, you'd see them right away. Then you have the turbo control actuator (much larger) bolted to the bottom of the manifold, which is visible from the bottom of the car. The car does weird things when that clip comes off. These types of clips rust and thin out over time and sometimes fly off. Have a peek and make sure they're in place. If they're gone, order new ones from Mazda. They're very cheap and always best to have a few laying around.

 

okay sorry havent had much time to reply lately!

Yes, thats what i thought as well so i pulled the couplers off again and checked them, they are all perfect. put the intercooler piping back together and still the same issue.


Im hounestly not to sure I had very little information about the cars history when I bought it, as far as I know theres are. and what do you mean by 7-7-7?

No the car is not running a boost controller.

Under WOT I falls on its face almost instantly, when I feather into the throttle it feels like Im making much more boost then the .5 bar that the gauge is showing.

Thanks everyone I really appreciate the help!

 

If it only falls on its face when you go WOT, then the tps may be out of spec. Had a car I tuned like that once where WOT would make too much voltage and trigger some sort of kill (not like a normal fuel cut when you overboost).

thewird

 

the 7-7-7 is a pattern...

from the factory the trubo's did a boost pattern of 10-8-10 (psi)

that pattern denotes that both turbos and all related hardware was working correctly...

we are curious, when you start at say 2000rpm, and ease into the pedal, the RPM climbs, you should see the boost gauge go to 0.7bar (10psi) then it should drop down to 0.55bar (8psi) then it should go back up to 0.7 bar (10psi)

thats what is ment when someone says 10-8-10


we would like to know what your boost gauge is telling you...

best way to check... have a passenger, and ask them to watch it, so your eyes can stay on the road..


J.

 

The FD is not all that DIY friendly, be careful what you do and don't do. And especially, be sure to keep your foot out of it until all is good!

A power fc , a wideband and a tune would pay for themselves if you buy them before you pop your motor.