speeddemon7

Ok so today was nice out and me and a buddy went out to try and find out why the car is limited to 6.9 psi max while also allowing the second turbo to come online.While checking things with a mity vac we found something somewhat unusuall.
We tested the wastegate actuator and the actuator hel vacuum and moved the inner workings accordingly.
Tried the same thing with the pre controll actuator and the thing doesnt hold vacuum.Is this normal? Also a very important question
When the car is off which way are the rods supposed to be? in or out for the wastegate,pre controll and also the tca. How will or should this change when the car is started? for exampl say the tca is out and then goes in when the car is started.

speeddemon7

new development.well maybe.
I jacked up the car to check out the turbo control actuator.The rod was pulled out and the rod was connected to the gate.So it wasnt an issue.
I then asked my buddy to start the car so I could see what the tca does when the car is running.
First the tca rod pulled in all the way then released.
On subsequent start ups the rod didnt even move all the way in.Barely moved a quarter of the way then settle back its idle position.
My question is whether the tca rod is supposed to be closed when the car is running at idle.If so I believe i have found my problem.

speeddemon7

anyone know the position of the tca door when the rod is out or pulled in? this info woud help me out a bunch.thanx.

LAracer

Have you tried this site for the info you need:

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

speeddemon7

thats the first place I looked.LOL
As far as everything else goes.Ive managed to find a bit more info in the fsm.
Im not quite sure whether the wastegate and pre spol actuators are supposed to act the same when testing the diaphragm.But if they are then the wastegate actuator is good while the pre spool is leaking and not holding vacuum.
Im still unsure whether the tca is bad yet.I need to run a few more tests to confirm or deny this.
Another question is this.Would a bad pree spool actuator cause me to be limited to 6.9 psi in the entire powerband? once again it fells like the second turbo is coming online even though it says that you need 8 psi for the actuators to work correctly.
I could really use some expert advice on this matter.

edv

Pill Issue? Your pre-control actuator works on vacuum AND boost pressure, regulated by the pill in the +ve pressure line from the primary compressor, no? If the actuator is pooping out, could it be a problem with the pill? Maybe.

speeddemon7

I checked to make sure the pill was there.Its in there but what I didnt know is that the pre spool works off of pressure and vacuum.
How can I test it then? The fsm says to use a vacuum pump and apply vacuum on one tit while closing off the other.Did this for both the wastegate and pre spool actuators.The wastegate worked the pre spool didnt even actuate.

edv

Funny, I tested mine with pressure instead of vacuum. I don't have a mity-vac...just a brake bleeder kit for vacuum testing. I think the FSM says to test these actuators with pressure and not vacuum, because the vacuum would bleed out through the pill, no? or is the pill like a check valve(ie one-way) I don't think so.
I went and got a foot pump with a gauge (for pumping up a low tire LOL) and used it to test WG and TPC actuators. Careful you don't push too much pressure tho. FSM says to limit pressure to ~7 or 8 psi if I recall. Both held.
Hope you don't need a new TPC actuator. I do not think they are cheap.

technonovice

There is a lot of good info there, but I have found at least one error there.

edv

I think that the thread starter will be asking you to elaborate on this assertion.

dgeesaman

iTrader: (7)

The TCA is 'in' with the TC door shut. It is important to have a little preload in the door - if you pop off the e-clip the TCA rod should pull in another 1/2 width of the pin (about 1/8"). I don't remember specifically how the KOKO sequence looks, but at idle it should be in. It will only be open when the secondary is on line.

The wastegate / precontrol should hold either pressure or vacuum (they are the same exact thing, relatively speaking) and pass the FSM test procedure. I don't remember the exact test setup, but I'm pretty sure you need to plug into both nipples on these actuators when testing. The same thing goes with these for the amount of preload with the e-clip removed.

I'm thinking hard and can't figure out how a bad precontrol diaphragm could limit boost on the secondary. It's essentially a valve between the exhaust and secondary turbo, and would only starve the turbos of inflow when the primary is working alone. But definitely start there if you see it isn't holding pressure.

Also, make sure the system can indefinitely hold pressure and vacuum. The KOKO test is a quick and dirty method (multiple KOKOs will test the capacity of vacuum and pressure), but directly using a pressure gauge it's easy to see if each reservoir in the pneumatic circuit is holding. And one more thing: make sure your BOV and CRV aren't switched - I believe the CRV cuts out around 7-8 psi, where the BOV cuts at 10.

The good news is TCAs in good used condition are everywhere. I have one in fact $40 shipped!). Dealer price is $600, gotta love that.

We haven't covered solenoids yet though they are the next level of troubleshooting.

Dave

speeddemon7

I looked over the fsm again and you are correct pressure not vacuum is needed to test the pre spool and wastegate actuators.I will check again using pressure to see if anything changes.
Also upon start up the tca rod moves all the way in and then pops back out.Doing this multiple times results in the rod not moving all the way in anymore.It moves maybe a quarter of the way in.Not sure what this is an indicator of but It may signify a leak.
ps: all the solenoids have a year or less on them.Theyre for all intensive purposes new.Or at least fairly new.The check valves however are not except for one of them.So this may be one of the culprits.Although being limited to 6.9 psi no matter what is very troubling.Something is broken since its a consistant thing.

speeddemon7

anyone else have a clue as to what could be happening?

streldoc

iTrader: (1)

You may have a split in the tubing going to intercooler or intake. Hard to find somtimes.

speeddemon7

all my intake and intercooler pipes are aluminum.Theres 3 intercooler couplers that connect all of them.I checked them out and none have a split in them.So thats out of the question.Im also running the efini which eliminated a very failure prone coupler from the equation as well.

edv

If all of the obvious stuff has been tested and checked, then another test you might want to try is with those 2 solenoids. Diconnect the vac lines, swap them, reconnect the vac lines, and see if you still have the same problem.
The reason I suggest this is because those 2 solenoids...TPC and WG...are not simple on-off solenoids. If I recall, they are duty-cycled by the ECU and one of 'em might have breathing problems (emphysema? hehe). I've not heard of this prob, though.
I would hate to think that the ECU is sending a bum signal...that would suck...but I've never heard of that either.
Just another check on the list of possibilities.

speeddemon7

the wastegate solenoid is no longer needed as the boost controller is taking over that factor.Only the pre control is needed now.

technonovice

IIRC the description of how to test the CRV is stated incorrectly. I admit my TCS skills are rusty, but I think the CRV is pressure controlled and not vac controlled.

The point being that you still have to use your noggin despite all the great work so many other have done.