How many miles on the turbos? Maybe they are shot.

 

The turbos have about 50k miles. They aren't smoking, leaking oil, or making any kind of bad noise. Other than that, is checking for shaft play the only way to see if they're blown?

I was going to leave the 2 green solenoids unplugged completely, but I don't think it would really help diagnose anything since that won't let the car boost above 6-7 psi, and mine isn't dropping below that anyway

I have one question about the CRV that wasn't explained in the troubleshooting guide, when you apply vac. to port-A (small nipple) to open the bigger ports, is the vac. supposed to leak out of port-A, or is it supposed to hold?

 

Awwww.... had my fingers crossed! It's nice when it's a simple fix.

 

Well make you one of this and rule out a boost leak

http://www.supramania.com/forums/sho...st-Leak-Tester

 

I haven't seen you mention that you tested the solenoids. Have you?

Dgeesman has a good pictorial in the FAQ.

 

I have some stock twins still in good condition, I can sell you. Just throwing that out there

 

Yeah I did do that, I mentioned it in the 1st post. The first thing I did was go simple sequential and checked and replaced all the solenoids

 

Vacuum should hold the CRV open without leaking off..it doesn't take much to hold it open, 8"with a mityvac ..when you pull off the vac, you will hear it snap shut
Are you asking about the CRV (blowoff for the secondary) or the charge control valve?



rph

 

The CRV (blowoff valve), reason is I have several that I was re-testing. When I applied vacuum to the small nipple with the mityvac, they would all slowly lose or leak the vacuum I applied until the valve closed itself again.

 

One thing I just thought of, but I don't think it really matters. About the caps that go on the solenoids that don't have a hose connected to one end. I'm assuming those are just filters so nothing gets into the solenoid? Or is it an actual closed cap so air/pressure doesn't escape?

I'm asking because I did notice that one of those caps had a crack along the side, so I don't know if that really affects anything?

 

Correct, they're filters.

 

Is your double throttle control working? Could the check valve be turned around or could it not be seeing operating temperature at the solenoid and be staying closed?

Just a thought...

rph

 

remove your y-pipe and make sure the o-ring is not damaged/torn/pinched etc....

 

The double throttle system was removed from the car so I don't have any of that stuff in there.

I'll check that out

 

Alright this morning I took stuff apart to re-check the turbos. And from my knowledge, they couldn't be in better conditions. The blades spin freely, the shaft has zero play when pulling it back and forth, and the play from side to side is so minimal it took me several hard tugs to even notice it. And like I mentioned before, no noise, no smoking, no oil leaking.

So I think it's safe to say the turbo's themselves are not the issue

I also checked Y-pipe and charge pipe to make sure the rubber o-ring is good and everything seemed fine.

What I'm gonna try to do next is make a pressure leak tester thing like mentioned above and see how that goes.

 

Update:

Yesterday I decided to just take the vacuum system apart and start over again. I found that the solenoids that I had tested thoroughly when I put them in the first time, went from good to bad very quickly and haven't been working properly. I only had 1 properly working solenoid, the others all had something wrong when energized, either leaked, got stuck, or didn't power on/off at all.

So now I'm gonna try and get some good ones and install them and see what happens from there

 

I just took out all my solenoids and was going to throw them away. If you want the one you need, pay for shipping and I will send them to you.

 

PM'd you

In the mean time I need to put everything back together, which do you guys think would be the more important to put the better working solenoid in, the charge control, or the charge relief?

Idk which one would be more of a cause to the secondary boost leak I'm having

 

Update: **Much thanks again to hondasr4kids for the solenoids, very appreciated!

Got around to replacing all the bad solenoids so everything there is working to spec

Took apart the y-pipe/charge pipe made sure O-ring wasn't damaged and CC plate was moving smoothly

Made sure gaskets from y-pipe to turbo weren't damaged or loose.

The car's still dumping boost the same way, idk what's next, so frustrating!

 

Yesss!! I got full boost!! Finally since the first time owning the car!!

The bad part is I had to go non-sequential to do it, I feel like a let down :-( . I just did the temp. poor mans version for troubleshooting. So, now I want my fully working sequentials back, lol.

I don't know if this is possible but this is what I was thinking of doing. I was going to plug back in one by one each of the sequential controllers until it didn't work again, will that actually work to pinpoint the problem?

Or do you guys have any further suggestions of what it could be?

 

Update, I seemed to have finally found the problem. I started by plugging back in each valve/controller one by one and testing the car afterwards to see what happened.

First put back the pre-control and the car boosted fine. Then plugged back in the CRV, worked fine. Then I plugged back in the CCA, and voila, no more than 4-5 lbs of boost.

The annoying part is that the CCA tests perfectly fine when you apply vacuum to it as the testing procedures say to do. What I also did was test the CCA with the vacuum port unplugged, but I left the other hose that connects to the y-pipe from port-B in place, and it also did not make any boost this way. So what my thought is that the inner spring is damaged and is closing the CCA from both port-A & B and not allowing it to open.

Next I'm going to plug back in the TCA and hopefully it still boosts fine. Then off to find a replacement CCA so that will hopefully be the end of it.

 

ZeroG, I was wonder if a new CCA fixed your issue?

I am having a very similar issue.

First, relevant mods:

-93 FD, stock seq twins in place
-PFC tuned
-GReddy intakes
-Pettit CCII SMIC and GReddy elbow
-Pettit 3" dp, RX7Store resonated catless midpipe, Blitz NUR-Spec catback (no cats)
-Snow Stage2 water/meth 350cc/min at full tilt
-Dual Hallman Pro RX MBC's to control pre-control and wastegate as per Damien's write up (PFC does not control boost)

The symptoms my car has: Primary boost good (10psi) then at 4500rpm boost falls to about 4psi and I can hear an audible boost leak. I have driven the car thoroughly and confirmed this is not an isolated incident.

The car had been driving great, boosting 10-10-14psi as setup with my Hallman Pro RX MBCs fine for miles and miles. Driving home from work one day I get into in 2nd gear and I hear a faint "POP!" and then boost falls to 4psi and I can hear the leak.

I got the FD in the garage and started poking around. The hose to the CRV was cracked. I replaced it and went for a drive- no dice.

This is what I have done thus far to diagnose my issue:

-Removed and tested CRV and confirmed functionality. Also swapped in a known good CRV from a friend's car and no difference.
-Removed and tested CCA and confirmed functionality.
-Removed and inspected y-pipe including rubber o-ring sealing the two halves. Retorqued the nuts holding the y-pipe onto the turbo compressors.
-Removed and inspected pressure tank, submerged in water and it 25psi for 5 minutes, no air bubbles.
-Tested check valve going to pressure tank and it checks good.

Basically I've done everything short of taking the UIM off and testing each individual solenoid. Reason being I would probably need to do a whole hose job since they are kind of hold. I did a quick visual inspection of all hoses and they appear good.

Any ideas on where to start would be much appreciated!

 

^Any input on what I should start checking or what could be my potential issue here with my secondary?

Thanks!

 

Bump! Same issue here! Do I have to go non seq or someone solved that?