Alright for those who dont know i had primary boost issues with my car running 7-4-5 for my boost. then after a lot of digging and checking, and rechecking, and then rechecking again, all the lines came back good, didnt check under UIM though...it turned out the pills were missing from the TPC and the WA vaccum line..but now my boost looks like this 10-5-5....I think that it might be the double throttle controls or check valve on it.....


Reason i think it might be this: when the car is running the rod used to be in, now its out and not holding at all...i took of the line and pushed in the rod manually, put my finger over the nipple...it hold perfectly....so i hooked the hose back up to the double throttle. i pressed the rod in manually again...i hear a hissssssss....so a leak !! i check again its under the pressure chamber, there is a vaccum line with a black round end attached to it. it is located by the empty pipe.

Now is this supposed to let air in and out, i noticed it had a filter on it to keep out oil, my guess... but could it be something else? possibly my double throttle check valve??? and if that is it, do you believe this would limit the boost 5 psi on transition? or could it be something else????

i would hook up a mitty vac but i just lost my job and am poor and just trying to bring my car back to life...is there maybe another way to test at all? Or if anyone has any suggestions im open for them...


Mods are as follows: hks catback exhaust...thats it...

 

ill explain a little about the double throttle mate,,, basically when the car is cold the ECU directs vacume from the inlet manifold by a solenoid to the double throttle actuator (this closes the second throttle plates (rod pulled in,,, suked in) this stops boost from going over a certain value,, think its 6psi),, once the car is warm the solenoid is switched off and the vacume is released through the air filter on the solenoid,,, and so the rod on the double throttle actuator is let out (throttle plates open)
basically ,,, the rod should be out all the time to get full boost,, rod is only in when cold to give low boost on warm up,
i pretty certain this isnt your low boost problem.

 

Alright so, apparently thats not it...I believe its the CCA...i just did the test on that and it works when i put my finger over the nipple, with the rod pushed in manually. Yet, when i turned the car off it was already out....i had the DTC and CCA mixed up somehow in my mind...I believe i will just have to put a new solenoid in there and see if this cures it....hopefully it does ill keep u updated!

 

just bumping so i can find it tomorrow and maybe someone to throw some insight my way

 

To save you a lot of time. Drop your exhaust system & try running around the block to check the boost from a free flowing pipe.

Its common for the CATs to melt down & the standard rear muffler to collapse internally blocking flow. The result is a loss of boost for no apparent reason.

All CATs & rear mufflers are the same design from 92 onwards

 

Charge control actuator is controlled by vacume through the charge control solenoid in a very similar way to the double throttle. (the vacume is taken from the vacume storage tank)
you need to make sure this tank hold vacume,,,start your engine let it run 30 seconds, then turn off,,,,now leave car 15 mins and then pull hose off vacume chamber,, you should hear the rush of air entering the tank,
Do u understand how the charge control actuator works,,,?
when car is off charge control rod should be out,,,when you switch the car to the on position the rod should pull in (using the vacume stored in the chamber)..

The charge control actuator blocks the air pipe between turbos 1 and 2,,,, at 4250 rpm the actuator should open joining the 2 turbo air pressures together.
dont think this is your problem,,, you would not get 10psi on first turbo if actuator was open all the time (you would be lucky if you could get 2psi),,,, only way i could think this would mess up your boost is if it was sticking shut and not opening at 4250rpm,, (this could cause a boost pressure drop),, i have a very similar problem to you,,i have a low 2nd turbo boost,,,,im still working on mine,,, let me know how you get on

 

DMRH,,, is suspecting a blocked CAT,,, he could be right,,,a blocked cat would only show up on high exaust gas flows,,,such as the high RPM range

 

i have a diagram i adjusted to learn this stuff i will try post it later,,,,its a too big file,,,need to resize

 

Here's the vacuum diagram: http://www.davidgeesaman.com/rx7/93v...lor.edited.jpg

As for the source of the 10-5-5, it could be the charge control actuator, but I would tend to lean in the direction of the turbo control actuator.

In either case, you should rent a mityvac from Autozone. The rental is not the nicest model (the gauge only reads in vacuum), so if you need to run a pressure test you'll need to tee in a separate pressure gauge to measure it, but it is free. Start by hooking it up at the CCA line, and verify that it holds vacuum indefinitely. (If it doesn't, test the check valves with the Mityvac, and if they pass, dig into the nest and find the leak). You can also hook it up to the CCA itself and apply pressure/vacuum to verify the actuator moves at the proper net pressure without leaking.

If all that checks out ok, tee into one of the lines at the top plastic (pressure) tank and verify that the pressure holds at 12psi indefinitely. Like before, if it leaks, look for bad check valves and/or loose hoses.

Those are the basics for the turbo control system - once you verify those are working as they should, we can do some more Mityvac tests to narrow down the source of the problem.

Dave

 

alright sounds good im gonna stop by autozone today and see if i cant rent there mityvac or see if someone around here has the 4050...thanks for the help so far everyone, ill keep this updated as i go along today hopefully the problem comes right out and shows me wouldnt that be nice

 

Alright this is almost narrowed down to where my car should be ready to go by tonight, i just need some help...i remember searching before and seeing a post about the cca sticking and how to test the solenoids...i cant seem to find that anymore..if someone has a link to that i would appreciate it..

Alright heres whats happening now...just replaced the pre cat with a dp....took it out and have the crv and abv vented to atmos...now if i dont give the car full throttle sometimes i can hear i believe the crv venting no matter the rpm...

While under boost i can hear a leak in the car in the cabin area for some reason...not sure what it is..its by the driver side bottom area...anyone ever experienced this at at?

Now i tested the cca and it failed when i tried to unplug the line from Chamber A i beleive...the rod was already out...could it possibly be the solenoid for this sticking causing my boost to flucuate...as stated before in that post i remember him saying that if he went from below 3000rpm he was fine...if he slowed down once boosting he would have trouble getting back up to 10 psi...i seem to be having the same problem...i have recently replaced the vacuum chamber...pressure chamber is fine...one way check valve for the pressure chamber, vacuum chamber and i believe the secondary air bypass along with another a green and black one...along replaced the airbox with intake....now i know the primary is working great i feel it pull like a mother....

does anyone have some insight at to what it might be if infact it is the cca solenoid or the cca itself? i dont believe it could be the turbo precontrol...

well thank you guys in advance..ive heard a lot so far from doing all of this myself..and just need a little more guidance on this issue..

 

You might as well have tacked this onto your previous thread, so I merged them. Next time look up your old thread and resume it.

Test the CCA as you did with the double throttle: pop off a hose, push in the rod, and plug the nipple with your finger. If it releases, the CCA has an internal leak. If the suction caused by holding the nipple covered keeps it from moving, the actuator itself is good.

And you verified that after running the car, both the vacuum chamber and pressure chamber hiss when you pull a hose from them?

Looking at the vacuum diagram, the green/yellow dot line going to the CCA comes from the output of the CC solenoid. To investigate this further, you need either a Mityvac or to get under the UIM to swap out this solenoid. I recommend the Mityvac since then you can get some used solenoids for a few bucks each and test them.

Dave

 

yeah i have tested it this way...with the nipple it holds when my finger is over it and the rod moves slighty like it is supposed to but then stays...were talking a few mm of movement..i know the vacuum chamber and pressure chamber both hiss when removing the hoses from them...ive tested on that before and recently...so pretty much just replace the cca solenoid and 11 9 11 here i come ????hopefully

this is the only thing i can think of that might be causing this..correct me if im wrong

no boost creep as of yet it holds firm at 11 when it does boost properly...right now its about 11-6-6 i believe

:edit:::: does it sound like the CRV could be leaking as well? i can get the solenoids for free so thats no problem...but i believe its normal for the crv to vent until under boost correct?

 

The CRV should only vent below 4500rpm. If it's not, it's either the hoses, CRV itself, or solenoid.

Since you say you can get known good solenoids for free, simply pull the UIM and replace them. To be sure, replace both Turbo Control solenoids too. But only if they are known to be good. Swap the CRV too if you can get one.

Dave

 

alright the vacuum and pressure one for the tpc, and the cca solenoid.. and the crv i might have a little trouble getting without paying for...i can hear it stop venting so i believe it should be good...ill go ahead and take the uim off and have some fun in there lol..

 

Alright everyone i got the solenoids replaced no broken solenoids when removing the rats nest...only thing i could not get back together was the connectors behind the uim, one is pointing down and the other up...they are on the uim itself...cant seem to get them to go on for some reason so i will try after work tomorrow and let you know if this solves my boost problem...thanks again everyone...

 

alright so i took the car out and i still have the same problem as before? boosting is the same 11 6 6....i replaced the cca solenoid and the tc + tpc solenoid in the rats nest...ne one have any other suggestions as to what it may be? i would check the crv but would this persist in my loss of 5 Psi? during primary second transition....i would think that it would be the turbo control, could that itself just be bad? too many diff things...even though i replaced the solenoids the cca test still failed i can hold the rod in when my finger over the nipple...yet when the line is plugged back in it just goes right out? could the line itself be bad? i didnt see any holes at all....but like i said before when im in the cabin of the car driving i can hear a loud PISSSSSS noise.....not sure where its coming from but it sounds like its in the cabin itself...only under high boost does it do this..im going to go swap my abv and crv around and see if it still consists so i can eliminate one more thing from my list..