Ok ,I replaced all the vacuum hoses to see if it will fix the second turbo problem and found some hoses in the wrong place, so I put them back by the book . Happy thinking that was the problem but it didn't fix it. Now the car idles high when it gets hot and still no sisn of secondary boost at 4500 rpm. PLEASE HELP....

 

unsure about high idle but if your hoses are all hooked up properly other than the turbo being toasted, you have bad solenoid(s) i had same problem , check your boost solenoids more than likely that is your problem

 

You won't get secondary boost until primary reaches at leat 8 psi.

You need a boost gauge. You can even use a $20 vacuum/pressure test gauge with about 6ft of vacuum/winshield washer hose.

You need to do a 40-70 run in 3rd gear. Cruise steady at 35 mph in 3rd . Floor it and have someone watch the boost and note the boost pattern. Be as thorough as possible.

You should get:
rpm psi
3,000 10
4,500 8 (as 2d turbo comes on)
4,500+ 10 (recovers almost immediately)
6,000+ 8 (and holds to redline)

Let me know what your numbers are.

Have you checked the usual boost leak culprits?
Y-pipe
Y-pipe coupling
1" diameter hoses
Primary Turbo Inlet
Couplers To/From Intercooler

You may have multiple issues.

1. Give a FULL report on your boost behavior based on the "chart" above. How it builds, drops... everything.

2. Do you have a vacuum/pressure test gauge? If not see if you can find one to borrow. They cost less than $20, but hey thats still $20. We will use this later.

3. We need to get the primary working. The Secondary Turbocharger requires the Primary Turbocharger to generate more than 8 psi to operate actuators that control the Secondary Turbocharger. So we will need to get the primary boost where it needs to be.

These are the easy ones to check:
Y-Pipe connector hose, (coupling)

* This is a very common failure part. This short hose, (coupling) will split and vent boosted air in copious amounts. The trick with this one is that when just looking at the part on the car it will look just fine. You need to remove the 90 degree plastic duct on top and completely remove the rubber coupling, then examine the rubber coupling by gently stretching it to see if there are any splits. Typically costs about $47 at dealer.

Check ~1" diameter hoses for leakage

* If you can rotate these hoses while attached, then the clamps are too loose. Get properly sized screw-clamps if the stock ones are not up to the job. New hoses will also help, but usually tightening the hose clamps is enough. A sign that there is air leakage is the presence of oily dirt on the aluminum casting around the hoses. New hose-clamps will set you back about $10 maximum for good ones. Note, clean up the oily dirt around the aluminum so that you will be able to see if these hoses start to leak again, (carburetor-cleaner works great).

Primary Turbo Inlet

* Typically collapses under high volume air through air cleaner into Primary Turbocharger. When the engine bay is hot the rubber is more prone to collapsing. Typical symptoms are having good boost at lower RPMs and then a loss of boost at higher RPMs, this is aggravated when engine warms-up softening the rubber allowing for easier and more complete collapse of the hose. Typically costs about $90 at dealer.

To/From Intercooler

* Same symptoms as the Y-Pipe coupler. When under boost, the hose-clamps prevent the hose from expanding due to the air pressure inside the hose. Do not under-estimate the force of 10 psi or more on 3" diameter hoses, what looks OK with engine not running may not work under boost conditions.

Giving me the full results requested above should help narrow the problems down. If it is a loud whoosh coming from the passenger side it cloud be a cracked Y-pipe.

technonovice@yahoo.com

 

my boost reads 10 @3500 then goes down slow to 5 till redline. I also tested the solenoids and they were good.

 

hey jalers. im having the same exact problem. i just ordered a set of the hose techniques so i will see how that goes. i will also be testing every solenoid and check valve to see if one of those may be the culprit. if after doing all this, nothing happens i will be taking mine back to ricks rotary. these cars are so nice, but i feel like its a freakin POS when its not running right.
kris

 

jalers-
What are your mods? If you still have the pre-cat, that could be clogged and could also be the main cat. Your symptoms are indicative of clogged cats.

There is a test you can do. If you still have your cats post it and I'll reply with the test when I have more time.

 

I STILL HAVE MY PRECAT AND I DON'T THINK I HAVE A MID CAT. SO WHAT ARE THE TEST TO DO FOR THESE?

 

BUMP

 

Jalers,

You have the precat but no midcat? Usually, it is the other way around. People usually mod the precat (w/ a downpipe) before replacing the main cat with a midpipe. Those symptoms you describe are consistent with a restriction in exhaust flow (clogged precat or maincat)

 

technonovice - you sound like you've troubleshoot more than one boost problem in your life...

k

 

jalers-

In assume you've checked for the leaks described above.

Also keep in mind that testing the solenoids in the garage or drive is not the same as when they are under the duress of the extreme temps during a drive. Teeing into lines will help you a lot more than pulling the whole solenoid rack and testing it cold.

Have you verified your pressure tank, vacuum tank and check valves yet? This really should done first or else the results in further testing may not be reliable.

To test the vacuum tank:
Tee into the vac tank with the vac gauge at either the vac tank itself, or the hose that goes to the solenoid rack. Same effect.
Run gauge into the cockpit.
Start car, go for a drive. You should see vacuum build up once the car starts and HOLD.
Then, the actual test is to find a hill and go up it in a higher gear where you won't gain much speed but will stay on boost for at least 10seconds.
Vacuum should remain high. If it drops, the first thing to check/replace is the check valve that feeds the vacuum system. Next would be hoses and looking underneath the plenum. Lastly would be a faulty charge
control/relief solenoid.

Another test to find out what is going on with your car is to tee your boost gauge into two locations:
1) The line that feeds the pressure tank, and tee into it before the check-valve: see boost build, drop at 3500rpms, build again and hold
2) The line behind the 1" charge relief 90 deg bend, which is the second turbo's activity: see nothing, boost builds at 3500 rpms, and holds. You should see numbers close to these below:

3rd gear - WOT

2000 RPM - 0PSI
3000 RPM - 0PSI
3500 RPM - 0PSI
4000 - 4500 RPM - Roll up to 8 PSI +-1PSI
4500 + RPM 10PSI

What is happening: Page F-84 in the manual

0-4000 RPM -
Precontrol controlled by ECU,
CRV off (Venting)
Charge Control Valve on (closed).
Turbo Control off

4000-4499 RPM -
Precontrol Optimized by ECU,
CRV off Charge Control Valve on (closed).
Turbo Control off

4500 RPM -
Precontrol fixed (5% open)
CRV on (closed) and Charge control valve off (open)
Turbo Control on

If you don't see any pre-spool before 4500 then the precontrol is not working.

If these two check out, then there are only a few more simple tests in the control system to check, but it points to either a clogged cat, faulty turbos (they would be smoking pretty bad), or a boost leak still present somewhere. A friends car had a leaky Y-pipe gasket and lost boost above 4500 rpms. The early ones are made of paper and later ones are made of metal.


nocab72-
I'm still learning.

 

technonovice- there are too many variables with these cars for any of us not to still be learning...

k

 

OK, TECHNONOVICE I AM GOING TO TRY THESE TEST AND I HOPE I FIND THE PROBLEM. THANKS FOR THE HELP. WE'LL SEE LATER WHAT HAPPEND.

 

Once you verify a few things get back with me and I'll give you instruction on the temporary Non-sequental set up which can help you diagnose a clogged cat.

 

yup i still got pre and midcats on but have a catback. if i put a down pipe and mid. what effects will it have to the car? am i going to need to upgrade other things too?
I have owned the 1st & 2nd gen. but this is a first with a turbo and i'm still learning these engines.

 

You might want to search that topic or start a new thread on it. Keeping this one on your sec. boost will make it complicated enough.

 

OK, TECH I DID THE PRESSURE TANK TEST ABD GOT BOOST THEN DROP AND THATS IT. T'D OF THE HOSE BEHIND THE 1" CHARGE RELIEF HOSE AND THE NEEDLE DIDN'T EVEN TRY TO MOVE . SO WHAT IS NEXT. DO I NEED A NEW TURBO OR COULD I REBUILD IT?

 

Seems you have no prespool.

1. Pre-control Actuator may be faulty.

2. The precontrol solenoid (solenoid J in the diagram) may not be functioning properly.

3. Hoses may not be connected properly (misdirected) or are leaking.

4. The connectors to your wastegate and precontrol solenoids may have been reversed.

 

If you have no pre-spool, would the second turbo still come on-line, although with lag? Same problem here. Was at 11-8-12 until last Saturday, when my boost went 11,hesitation, then slow drop to 0 psi and feels like the primary turbo is overloaded and bogs the car.

 

oh no..not you toadman!

Im having similar problems....I have not run thru it all yet to read boost at all rpms as I had to break in the motor....was not experiencing high boost til at least 6500 rpms. There was not a noticible kick for the second turbo and boost did not change rapidly....finally tried to solve the problem (m2 claims the ball bearing set will not operate efficiently without running at least 13 lbs) but will have to wait until monday or tuesday to get tuning time in past the current stock levels.

I will definitely look to this thread for answers either way. THANKS TECHNONOVICE.



j

 

how can I troubleshoot the second turbo to see if it is good? i just put new hoses on and i went by the diagram thinking that would fix the problem. where are those solenoids located for the precontrol and those connecters?
We get so much help on this site. Don't know what to do without it....

 

I think you could have multiple problems. Be patient and be as specific as possible when posting.

If boost fades at 3500 rpms you either have a boost leak and should hear wooshing of leaking air, and/or you have a clogged exhaust that is restricting boost.

Hopefully replacing vacuum lines in hopes of fixing boost did not create more problems.

1. For kicks check to see if your connectors to the precontrol solenoid and wastegate solenoid have been mistakenly swapped.

They are located under the crossover tube and pressure tank. They sit side by side with the precontrol solenoid on the left (blue and yellow wire?) and the wategate solenoid on the right (blue and white wire?). The colors fade from the heat and hopefully someone can verify that I am correct on the colors of the wires. They are very easy to get reversed. You could try swapping to see if it helps boost. If not then they were likely correct.

2. For kick number 2, did you check your codes? Do you know how? How to:
http://7sins.rx7life.com/errcodes.htm

3. What do you get from the vacuum tank test?

A friend pointed out that you are likely not getting any Turbo Control. Until you fix and/or verify that the Turbo Control valve is opening then you cannot rule that the turbo is bad which is possible but unlikely.

Back to Turbo Control:
Solenoids
There are 2 solenoids that connect to the Turbo Control (TC): one provides pressure on one side of the actuator diaphram and the other supplies vacuum on the opposite side.

Vacuum/pressure lines:
The vacuum tank provides the vacuum needed for the actuators via solenoids including TC.
A leaking vaccum tank can cause problems. The best way to test it is with a Mity Vac. The check valve between the vac tank the manifold can fail also. You should be able to blow thru the check valve from only direction. it is possible that the valve has been removed and replaced in the wrong direction. So do the vacuum tank test.
Similar to the vacuum chamber (tank) is the pressure chamber (tank) and its accompanying check valve. It of course provides the needed pressure.

Actuator:
Make sure that the clip has not disconnected from the Turbo Control (TC) actuator arm and the Turbo Control (TC) valve. I have heard and read a few cases of this. It could be this simple.

Here are some diagrams if you need them.http://7sins.rx7life.com/diagrams.htm

Do you have a high speed connection?

-mf

 

Technonovice,I've got a question.I put on a profec-b about 2 months ago.I never really got the feel for tunning it.So I switched my setup around a nd went back to my stock ECU and a PFS Purple.My previous was a stage3 M2.Anyway After getting the Purple on a week and a half ago.I still havent gotten the boost dialed in correctly.I can get a nice solid Primary then no matter what mode Im in at transition it drops to 5 or 6 psi then sometimes will creep back up to where the purple is set at for secondary.I also get the loud wooshing of venting boost from the passenger side.I first noticed this when I installed the ProfecB.I assumed this was normal. Now Im wonderimg should this be approached as a boost leak or as a Purple box tunning issue?

 

yea i do have cable modem.
I have tested the vacuum and pressure tanks and all the check valves when i redid the hoses. i'll try to see if i find something with the tc ,and inspect all rods and connections.

 

Jalers- if you don't have a FSM (shop manual) download one here:
http://www.iluvmyrx7.com/Technical_I...ice_manual.htm