viper_u27

hello everybody
ive had this boost pattern ever since i bought my car a couple months back. ive done some searching, but cannot find a real match. boosting pattern is always the same and there was also oil found in the intercooler. the downpipe gets a lot hotter than it should, enough that it changes color. this leads to believe that maybe my main cat is clogged??? that would explain the turbo's being overworked and have oil spitting into my ic piping. anyhow, im thinking of just going non-sequential and forgetting about all this boosting problem mumbo jumbo (single is out of my financial ability at the moment). but just wanted to know what you guys think or if anyone has had this kind of pattern before.
thanks!

rotarynemesis

I did with my old car and it turns out that there was a bolt stuck in the secondary turbo and that it was there from when mazda replaced my engine. Just look for a good set of used twins in the forsale section.

And you should only modify a healthy car. Get it running right and then decide where to go with it. Going non seq will not fix the boost problem if the turbos are bad.

busy13b

iTrader: (5)

here are two possible causes:

The c/e-clip that holds the "turbo precontrol" actuator rod may have broken, allowing the actuator rod to slip off and not function at all. You can easily access the actuator from underneath the car - it's the one closest to your face If you get under there and find out you DO need a new one, make sure you actually get the mazda replacement - i dicked aroud trying to get a hardware store e or c-clip to fit and only ended up with bloody nuckles and a garage full of profanity

The mazda p/n is: 9957-50-400


Another possible cause is a failing turbo control "solenoid valve" - in other words, the fragile thingy that is attached to your air control valve. It is possible that one of the vaccum hoses has popped off, or one of the nipples has actually broken off.


See both items/areas here:

http://www.wvinter.net/~flanham/wlan...urbosystem.jpg



Just curiously, do you have the factory pre-cat or an aftermarket downpipe on the car??

Madmax670

can you describe your boost pattern a little more thoroughly, it is hard to help without more information, go out and drive it, do you always get boost in every gear, try shifting from high rpm's and see if you still get no boost, i am also currently fighting boost problems, try to be more specific

jaj1

Take a look at this site for some turbo troubleshooting info and procedures.

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

Nghtstlkr7

i had the exact same problem shortly after buying my car. 8-4-3 and falling to zero by redline. this was every gear and downshifting only produced a "hit the wall" effect where id lose a massive amount of power. turns out that my main cat was clogged. i got under the car the otherday and unbolted it from the downpipe leaving a half-inch gap. got my 11-9-11 back.
my suggestion is add that procedure to your diagnostics before you go nuts tearing things apart. also check all your couplers and 1inch hoses for loose clamps, tears and anything that maybe out of the ordinary.
start simple and work your way up

viper_u27

thanks everyone for their input. sounds like Nghtstlkr7 had exactly the same problem, doing the same boost pattern in every run. lets see if i can figure her out...

edv

If your pattern goes to ZERO right after transition, then another possibility is the Charge Relief Valve stuck open and venting ALL boost to the atmosphere as soon as the charge control actuator opens the butterfly in the Y-pipe.
The usual culprit for this is the Charge Relief Solenoid...either it's bad or a hose has popped off.

I am suffering the same problem right now, and I'll be testing that solenoid today.

Fixing these problems is very easy. It's FINDING the problem which is not so easy.

viper_u27

ok, the whole day ive been trying to see where this boost leak is happening...

checked the main cat and there are absolutely no clogs at all. i lit a flashlight in there and i see only clear mesh. i also tried driving with a gap between the down pipe and cat (wow was that loud!), but still the same boost pattern.

i also checked selenoid valve and pre-turbo control actuator...no luck

im thinking ill check the charge relief valve, and if nothing happens ill give it a silicone hose job. if this fails as well, im guessing its the turbos.

any more suggestions???

scotty305

iTrader: (2)

reset your ECU if you haven't already?

-s-

Madmax670

i have the same boost pattern and i also get little to no boost when shifting at high rpm's, my boost gets to about 8psi and at 4500k, it falls to under 5.

viper_u27

madmax, have you had any luck solving the problem yet???

Madmax670

replacing all of the check valves helped, but im still working on getting it perfect

viper_u27

i was so happy the other day that i found a hose that was popped off (the secondary air bypass that goes through the side of the y-pipe just before it connects with the pressure regulator), only to find that my problem still persists. im learning now what people mean when they say they have a love/hate relationship with their sevens. thanks for feedback guys, im still going at it.

Madmax670

viper, if u ever solve the problem please post it, im always looking for a solution to this boost monster