weetbix13

Hi everyone, last night, for the first time since my finished rebuild i 'found' the second turbo... we did a test cause it felt so slow.

0 - 60mph in 7.5 long, arduous seconds shifting at 5,250rpm or so.
that was so depressing, and there was no sign of the secondary so we decided to do a boost pattern check run in 2nd gear.

5,500rpm - there it was! raced to fuel cut (i had a friend watching the boost gauge noting the pattern but he was shocked by the secondary and looked away)... gutted to hit fuel cut... and clutch smoking like a $2 hooker after making $100 in a night from a **** poor launch and worn plate... but stoked to find the secondary.

now, can anyone help me convince the secondary to come to the party earlier?
boost pattern is controlled by two bleed valves and is:
10 - declining to 7- ##%$$ (at 5,500rpm)

i have searched and the common thread is the turbo-precontrol. i have this on a bleed valve system and the solenoid completely bypassed, if i bleed this more, that'll bring the spool in earlier right? but doing that would increase my primary and put me out of the ballpark on primary charge unless i maybe turned my wastegate bleed down right?
(MBC masters chime in with relative settings, perhaps i need to tune my precontrol bleed DOWN?)

could also be a clogged cat, the car smells odd (rich + mystery) on warm up which may be the cat not being truely effective... air pump clutch tries to engage during idle but the pulley isn't visably turning which could contribute to a clogged cat.

i'm not at altitude... so that doesn't figure in.
thank christ for RA3mm seals... second time my car has overboosted and is still seeming rock solid... i'll use these again.

also, car idles rough after boost runs, not sure if it is related but good to have all the info in one place. also, i'm sure i could hear a reasonable 'wooshing' just below 0psi boost/vacuum.

any thoughts? things to check?

weetbix13

come on guys! the post isn't that long!

dgeesaman

iTrader: (7)

Cat: unbolt it from the car, shake it and look for loose stuff inside. The air pump I believe should not be active at idle, but I could be wrong. The details of the secondary air injection are listed in the mazda factory service manual, section F.

I think you should leave your precontrol alone. Open it too much, and you'll get a dangerous boost spike when the secondary is working. Too little, and you'll just get a little more delay until the secondary is fully online. The precontrol is not required to getting the secondary on-line.

Did you attempt a run with the charge relief valve unplugged from the air filters to make it more audible? If it makes any noise above 4500rpm during throttle, that would be the problem.

Those are the easy things to check.

Solenoids: Run a KOKO test. (www.fd3s.net/boost_test.html). I suspect your turbo control door may not be opening.

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Then here is the operation checklist developed by the Mazda Training Center in Pleasanton, CS:

93-95 RX-7
BEFORE AND AFTER SERVICE OPERATING INSPECTION

STEPS SHOULD BE DONE IN ORDER. FAILURE OF ANY STEP REQUIRES FURTHER
INSPECTION BEFORE CONTINUING.

THESE READINGS INDICATE NORMAL OPERATION
(Readings may vary with altitude and temperature)

1. CHECK FOR PCM CODES AND REPAIR AND CLEAR BEFORE ANY OTHER
PROCEDURE .

2. VERIFY ENGINE IS AT OPERATING TEMPERATURE
- REMOVE DOUBLE THROTTLE VACUUM LINE AT ACTUATOR
- AT OPERATING TEMPERATURE NO VACUUM SHOULD BE PRESENT WITH
ENGINE IDLING.

3. CHECK ENGINE VACUUM AT IDLE
- REMOVE RUBBER CAP ON EXTENSION MANIFOLD
- INSTALL VACUUM/PRESSURE GAUGE ON EXTENSION MANIFOLD
- VACUUM READING SHOULD BE ABOVE 15" W/AC OFF

4. CHECK NO LOAD OPERATION Of TURBO
- BRIEFLY ACCELERATE ENGINE TO WOT IN NEUTRAL
+4 PSI SHOULD BE OBTAINED
- WATCH THE PRECONTROL ROD FOR MOVEMENT


5. CHECK VACUUM TANK'S STORAGE ABILITY W/ENGINE OFF
- PULL OFF VACUUM HOSE AT CHARGE RELIEF ACTUATOR
- SHOULD HEAR AIR ENTERING HOSE VACUUM
- START ENGINE - BRIEFLY ACCELERATE ENGINE TO WOT IN
NEUTRAL AGAIN
- ENGINE OFF - KOKO 6 TIMES
- WATCH CHARGE CONTROL ACTUATOR WORK EACH TIME
- WATCH TURBO CONTROL ACTUATOR WORK EACH TIME

6. CHECK PRESSURE TANK'S PRESSURE STORAGE ABILITY W/ENGINE OFF
- PULL OFF FRONT HOSE OF PRESSURE TANK
- SHOULD HEAR AIR LEAVING TANK (PRESSURE)

7. ROAD TEST WITH VACUUM/PRESSURE GAUGE INSTALLED
- DRIVE TO THIRD GEAR WITH NORMAL ACCELERATION
- ACCELERATE FROM 35 MPH AT WOT UNTIL PASSING 4500 RPM
- A SLIGHT AND SMOOTH INCREASE IN POWER SHOULD BE FELT AT
APPROXIMATELY 4500 RPM. THIS WILL BE ABOUT 65 MPH.

PRIMARY - GAUGE NEEDLE SHOULD BE ABOVE 10PSI UP TO 4500 RPM

SECONDARY - NEEDLE WILL DROP TO ABOUT 8.0 PSI JUST AFTER 4500
RPM
STARTS - NEEDLE WILL THEN BEGIN RISING TOWARDS MAXIMUM BOOST
DEPENDING ON LENGTH OF TIME THROTTLE IS HELD.
- RELEASE THROTTLE

WOT = wide open throttle
KOKO = Key On Key Off

REVISED FEBRUARY 11. 1996

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