Herblenny

iTrader: (13)

O.k.. I need some one who's very knowledgeable to help me with my problem..

This problem is kind of weird..

List of mods related to turbos..

Greddy 2row, efini-y, simplified seq. turbo set up w/ blocking plates, Apexi bov, stock CRV, Blitz intakes, PFC, AVC-R... FULL EXH.

My problem:
When I first start driving my car, primary hits perfect.. I could drive all day just using primary.. BUT!!! Soon as I hit secondary turbo, My turbo goes into non-seq. mode..

At this point, My primary will only hit max of 3-4lb of boost.. And after 4200 RPM, it will hit 13-14LBs..

This is driving me crazy.. Once again.. Only after i hit secondary boost.. long as I don't hit it, my primary is fine.. This happens off and on.. and lately it happens all the time..

After day or two, I get boost in primary.. but when i hit secondary, its goes into non-seq mode and all the boost comes on at 4200..

SO, so far, i checked all the lines, 4 solenoids, AVC-R, IC piping and couplers,

And today, after it went into the non-seq mode, I lifted the car and check the actuators..

My question is:
1. do any turbo experts out there know what I should check for??
2. The turbo control actuator.. when the engine is off, is the rod coming off of the actuator supposed to be IN or OUT??
3. Do Turbo Control Solenoids go bad when heat is applied?? but this happens when I first crank the car and hit secondary??
4. with simplified set up, would any other solenoids could cause this problem??


Any help to resolve this issue would be greatly appreciated!

Thanks!

PHIL

rockshox

iTrader: (3)

i would check to make sure the check valves are working correctly and the tanks are holding pressure/vacuum.

spurvo

So it sounds like you are having slow transition, and then when it does transition, you are getting boost spike. If your charge releif valve was closing late, this would bleed boost to the intake at transition until it closed, then when it closed stuff the overspun primary and secondary boost into the intake, giving a nice fat spike. So I would first check to see your charge releif valve was working properly (opens at the right amount of vacuum, and opens smoothly, not sticky, and closes smoothly). Next I would check to see the charge control solenoid is opening to the vacuum source when it's supposed to, and closing when it's supposed to. I think you can tee in a vacuum gauge to the charge releif valve and watch to see how it responds. Lastly, you should make sure your vacuum chamber is retaining vacuum. Have you seen the FD turbo troubleshooting website? They have a proceedure where you turn the ignition on and off (don't actually start the car) and watch the turbo control solenoid. It should move in and out each time for ten times. If it doesnt, you aren't retaining vacuum. Remember that the vacuum is necessary in the chamber to open the charge releif valve under boost, as of course there is no manifold vacuum just then

Anyway, that's my suggestion. It could also be a slow turbo control valve which typically is a result of not having both the vacuum and pressure chambers properly working, as both are needed to actuate that valve fast enough at transition.

This was a long repetition of rockshox's idea to check the check valves. Also, I'm no expert in the twin control, but this guy's site IS!

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

Hope all goes better! Watch those spikes!!

Rotarded

Greetings Phil,

1. I am NOT and expert but, I believe you are on the right track with the solenoids and actuators.
2. The Turbo Control actuator rod will be in when you turn the key on and the vacuum chamber has vacuum which pulls the rod in ,key off the rod goes out. This is one of the ways you you check the vacuum chamber. The KOKO (key on/key off) 6 times should move both the charge control and turbo control actuator rods.
3. Yes they do. I had a TC solenoid that worked perfectly when cold (ambient temp), but would only work correctly intermitantly when the engine was at operating temps.
4. Dont' have a freaking clue, never have seen or worked with the simplified set-up.

Mike

P.S. If you still have my cell # (from the Revolution), give me a call. It's a roll of the dice whether you'll catch me at the RX7Store.

Herblenny

iTrader: (13)

Thanks guys..

Well, these are the things I have check over past couple of months..

I know that all the check valves are good..

I initially thought it was the CRV.. but I don't think it is.. because I get full boost at 4200.. and I get .85 bar..

I thought maybe the actuator that controls the flap (Charge control) for secondary, but that works fine..

And I don't think its my Vac. Chamber, since other actuators works fine and also, I have clear silicone hoses to see if I have any oil going thru the line.. and I don't see any oil residue.

Only thing I see is that might be is the turbo control actuator at the bottom of twin turbo..

By what Mike said, the actuator rod should be out when the engine is off.. I checked it yesterday and it was in..

Can someone elaborate what might cause this?? is this mean vacuum is still present in the line and that I could un-do the line and shoule pop out?? I tried to pull the rod and I felt resistance to pull it out.. So, I'm assuming this might be the problem.. That is the one reason I asked in the beginning.. I wasn't sure if this was supposed to be pulled in..

Also, can someone tell me how turbo control works.. I wanted to make sure if my understanding of it is correct.

Thank you!

PHILIP SOHN

Herblenny

iTrader: (13)

Oh, I have checked this site many times..

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

911GT2

Ok, so let me summarize just to make sure I understand whats going on.
-Your Charge Control Actuator (allows secondary pressure to be added to primary) works fine, and gets correct pressure to both sides.
-Your Turbo Control Actuator rod is in (flapper door is open) when the car is off, and it should be out. (flapper door closed)
-The Charge Relief valve (vents secondary pressure until 4500 rpm) works properly.

If your lines to the TCA have the correct pressure/vacuum in them and it works when cold, I'd think its probably the Turbo Control Solenoid, or pre-control solenoid. Have you tried switching the two electrical connectors behind the pressure chamber? If your pre-control isn't working, switching the two would make your wastegate solenoid control the TCA, which might alleviate the problem. It'd be temporary, but at least you'd know what the problem was.

Herblenny

iTrader: (13)

911GT2,

I have AVC-R.. I thought it was my AVC-R at first.. but I think its fine.. the avcr replaces the two solenoids behind pressure chamber (solenoid I and J).

I think i'm going to try to replace the solenoid E, turbo control underneath the upper manifold..

and I guess it could be the pressure side of Turbo Control.... Because I don't think pressure is going to the Turbo control actuator.. i'll check into it..

Thanks!

911GT2

Oh, I didn't know the AVC-R replaced those solenoids. Hmm.

Let us know how the TCA pressure side test goes.

Herblenny

iTrader: (13)

I checked the pressure chamber.. since its easy to check.. and it was fine.. I think its my solenoids to control the actuator.. I'm going to change out the solenoid tomorrow..
My guess is that the pressure side of the turbo control solenoid is not opening to send pressure to the turbo actuator.. Since the vacuum still remain in the system, I think that's why the actuator rod is pulled in.. instead of out.. Also, I pulled the pressure side of the actuator and I didn't hear any air coming out..

Herblenny

iTrader: (13)

here is the link to the simplification diagram

http://www.rx7turboturbo.com/robrobi...simplified.jpg

TTBullet

herblenny,
so, how did it go? i'm having same issue.

Herblenny

iTrader: (13)

I'm in Cincinnati, OH for work.. I'll probably work on my car this weekend..

TTBullet

herblenny,

any luck?

Herblenny

iTrader: (13)

I haven't done anything yet.. I'm changing my oil tonight..

I'll check into it this weekend.. I think i might of switched the lines.. its possible.. i'm going to check the solenoids and stuff..

if it still does it, I'm swaping turbos.. I have couple of stock twins.. with better exhaust manifold..

Herblenny

iTrader: (13)

TTbullet,

Well, yesterday morning. I finally had a chance to take my car apart and find out what might of caused my seq to non-seq problem..

after checking all the solenoids, and vacuum and pressure lines..

I found out that i have switched the lines off of the turbo control solenoid ( the one solenoid that looks different from all other.. I have simplified seq system.. but if you have stock set up, its next to ACV).

I had to get my rats nest out and follow it thru with the diagram..

Soon as I switched back.. my car ran like a champ..

Hope this helps.. if not, let me know.. man I never thought I would have this many turbo issues.. but now I feel like an expert..