DVSseven

IM GETTING A WEIRD FLUCTUATION/WHISTLING NOISE HEARD UPON TRANSITION AND THE SECONDARY WILL NOT COME ONLINE UNLESS I QUICKLY RELEASE THROTTLE AND QUICKLY TIP BACK IN. ALSO SOMETIMES AFTER THIS HAPPENS WHEN DOING A WOT RUN THE EXHAUST NOTE CHANGES THE CAR WILL NOT BUILD BOOST MOMENTARILY, LIKE SOMETHING IS STICKING. AFTER I LET IT IDLE FOR A MOMENT IT WILL RETURN TO NORMAL, I BELIEVE POSSIBLY THE BUTTERFLY VALVE INSIDE THE Y-PIPE. JUST WONDERING IF ANYONE HAS ANY INSIGHT.

p.s. POSSIBLY FOR SALE

JAMIE....

DVSseven

C'mon Guys Please Help...

dgeesaman

iTrader: (7)

Run a KOKO test and see if that valve is cycling like it should be. If you do it after the car was run recently you don't need to do the step where you rev in neutral, since the vac and pressure tanks should already be charged.

It's at the bottom of this page:
http://www.fd3s.net/boost_test.html

Does this mean you have the car running? (last night you were troubleshooting the smoking thing)

Dave

DVSseven

Yes Its Running And I Believe With My Fingers Crossed That I Fixed My Performance Problem As Well. And It Also Does Not Smoke Either, Not Sure What The Problem Was. Only Thing That Was Lose Was The Vaccum Line For The Double Throttle Actuator. I Did A Few Transitional Runs And At Transition It Fluctuates And Whistles. I Have To "blip" The Throttle At Transiton In Order To Engage Secondary Turbo, If I Do Not It Just Continues To Fluctuate.

DVSseven

Im Not Able To Do The Koko Test Due To No Help To Watch The Actuators While I Perform The Test.

DVSseven

Another Reason To Sell The Car! No-one Ever Available To Assist In Repairs... Or If You Do Get It To Them They Cant Figure It Out, Like Pettit.

DaveW

Whistling could be a bad check valve (pressure or vacuum tank) or a leak in a hose in the turbo-actuator lines.

DVSseven

Dave, Got Any Pic's Of Turbo Actuator Lines?

DaveW

No pics, but the turbo actuator is just to the right of the oil pan (covered by some shields to keep exh heat off). Do you have the vacuum hose & boost control diagrams? If not, here they are...

DVSseven

So Basically I Need To Follow The Lines And Inspect Them For Leaks, Due To Being Torn, Ripped Etc...?

DVSseven

I Had Dale Clark Replace The Check Valves With New Ones That He Sells, So I Doubt That It Is A Prob. With Those. This Was Probably Only 4 Months Ago...

DaveW

Yeah - If you still use the stock solenoids, I'd suspect a line in the circuit from the pressure tank thru the solenoid to the actuator, or the solenoid, itself.

EDIT: A leak that could cause this could also be in the tube going to the pressure tank...

My reasoning: The turbo actuator needs both pressure and vacuum to fully actuate. As boost builds, a split in the line could open, partially closing the turbo actuator. The line would close, boost would build in the pressure tank, and the scenario would repeat. Lifting off the throttle would recharge the vacuum tank, momentarily overcoming the problem caused by the low pressure on the pressure side.

dgeesaman

iTrader: (7)

Yep, I'll bet the whistling sound is as simple as a forgotten or mis-connected vacuum hose. No matter how well I think I know them, I still cross them up or forget to connect a few.

If you have a mityvac, it's pretty easy to tee in by the pressure or vacuum chamber, pump in air, and see if it holds or leaks. That should help you track it down.

Oh, and since you have reason to believe the turbo problem and the leaking hose are related, check out this diagram:
http://www.davidgeesaman.com/rx7/93v...sequential.jpg

Only the ones in color are part of the turbo control system. So focus on making sure these are all correct.

Dave

DaveW

After more thinking, a boost-coupler split could also cause this whistling and fluctuation - same reasoning as above. I still think the control circuit tubing, etc., is more likely, but it wouldn't hurt to check the couplers.

DVSseven

Yeah, Ive Looked At The Couplers. I Do That Any Time I Open The Hood Because I Had That Problem In The Past.

Dave, Are You Talking About The Black Pressure Chamber In Front Of The Wg Control And Turbo Precontrol?

DVSseven

Where Would You Guys Start?

Conv.WS6

personally I would start with the vac hose diagram and make sure everything is going in the right place. If you don't have silicone hoses already it would be a great time to do the replacement. If after all that is done, and you have inspected all the check valves and replaced them I would test all the actuators, and the see if the vac tank is leaking. hope that helps. goodluck.

DVSseven

In The Control System That Is....

DaveW

Yes - the pressure chamber you can see on the engine just in front of the UIM and the 2 solenoids you mentioned.

DVSseven

Ok Thanks!

Conv. Ws6, The Actuators You Are Talking About Are The Ones On The Turbo's Themselves Correct? If So, Is There A Way To Check Those Working Alone Cuz Its Just Me Here....

dgeesaman

iTrader: (7)

It's tedious, but you can do the KOKO test by yourself.

(with the vacuum and pressure systems fully charged), key on. Get out of car, look to see the position the valves are in. Key off. Look again. Key on, look again. Each time you key on or off, the turbo control valve and the charge control valve should extend or retract. These are the valves most likely to be responsible for secondary transition issues.

(The wastegate and precontrol actuators never move in this process - they rely on direct pressure from the compressor)

Dave

DVSseven

Dgeesman, Could You Tell Me At What Position They Should Be In With Ko Or Ko? Key On-what Position? Key Off-what Position? Sorry To Be A Bother, And Thanks....

Jamie

dgeesaman

iTrader: (7)

Don't forget to do this with the pressure and vacuum tanks charged (the neutral rev step in the KOKO procedure).

Key on:
- Charge Control solenoid is energized, and sends vacuum to the CC actuator. Vacuum pulls actuator rod in (valve closed)
- Turbo Control solenoids are energized, vacuum and pressure are diverted to the TC Actuator. Vacuum/Pressure pulls actuator rod in (valve open)

Key off:
- CC solenoid is deenergized, air flows in from y-pipe thru the solenoid to the actuator, releasing the actuator. Rod goes out.
- TC Solenoids deenergize, pressure or vacuum is released through the solenoids. Actuator rod goes out.

Dave

DVSseven

Dgeesman, Would You Possibly Have Pic's Of Exactly Which Valves Im To Be Looking At?

Thanks, Jamie

dgeesaman

iTrader: (7)

The Charge Control Actuator is the golf ball-sized one in the middle of the y-pipe. The Turbo Control actuator is the beercan-sized one beside the oil pan. You can really only see the position of the rods - of course, the valve is hidden inside the system.

Dave