RotaryMan88

Whats up w/ this.....is it the motor? turbos? something in the control system??? HELP!

sejanus

99% it'll be the control system

check for popped off vacuum hoses

RecKleSs

Check your ic hose, y-pipe, vacuum hoses and your solenoids. Most likely there is nothing wrong with your engine. It sounds like a minor problem.

ejmack1

Turbo control solenoid underneath th UIM

7-sins

I have the same problem, it is driving me nuts. I might just take it to a pro. If I find anything I will post it.

Chris

3rdgenowner

Man dont tell me we have the same name???

ejmack1

Wonderful world of Sequentials

sejanus

they fixed the sequential problems with the 1996 "series 7" update of the car, pity they didn't when they first released the car!

7-sins

Ok, after another night of battling it out with the car... From what my friend and I have seen, my turbo pre-control and wastegate actuators are not moving. At first I assumed it was a problem with the actuators but really its more like something is wrong with the controls for the actuator. This would make sense because the turbo pre-control actuator opens up to spool the 2nd turbo... if it's not opening, the 2nd turbo doesn't spool. When the charge control actuator opens like it should, the 2nd turbo isn't spooled. Therefore instead of the boost of power from 2nd turbo entering the system, there is only a lack of power because the 2nd turbo isn't even spinning.

So we went to trace the problem... next on the line were the turbo pre-control & wastegate solenoids. They both worked like they should, basically one-way valves unless voltage is applied, then making the valve free flowing. We tested these as stated in the manual, hooking them up to the battery as the source of voltage... ect. The way I figured it ties into the turbo system is by looking at it as a loop. Under low load the computer keeps the valves free flowing, so a little pressure from the primary turbo is passing through the actuators, through the solenoids, and back to the intake elbow so the turbo can suck it back up again. When the computer senses a large load it will remove the voltage from the solenoids. The solenoids close and stop the loop. Now the little pressure from the turbo is blocked off by the solenoids. The only place that pressure can now go is to build up in the actuators, opening them.

What we figured was the solenoids are never closing, which wouldn't open the actuators so the 2nd turbo could spool. Since we tested the solenoids and they worked then the problem might be before the signal gets to the solenoids. We were thinking wires going to the solenoid or sensors that would make an effect on the solenoids behavior. That's where things get complicated and I would need computer diagnostic.

I thought it would be an all-common vacuum leak, but my vacuum shows fine at idle say 16-19 inHg. We used carb. cleaner to spray around vacuum lines and see if the engine bogs down... no luck. Symptoms are: 0 psi after 5000 rpms, running rich (no A/F ratio but carbon build up on rear of car as well as poor MPG), and 0 psi in 2nd gear if I shift from 1st after 5000 rpms.

Some of my assumptions on where the problem might lie may not be 100% correct, if not then please correct me. Every time I fool around in the engine like this I learn a little more from last time. I figure if we all put in a little information we might be able to narrow things down. From what I am seeing now... the best thing would be to bring it to a dealer and have them use one of their fancy computers to JUST diagnose the problem. That is an assumption the problem is based from an electrical portion of the engine. If I do I will post results.

Once again please let me know if my assumptions are off because it will narrow down the problems. Here is a link to a large vacuum diagram, which helped me come to my conclusions.

http://www.geocities.com/MotorCity/G...route_diag.gif


Before I finish this off there is one more thing I was thinking about trying... remove the electronic harness to the turbo pre-control & wastegate solenoids. Thus making the valves one-way all the time. This would allow the actuators to move as soon as the primary turbo had enough pressure to do so. Basically making a non-seq. set up, being that the solenoids had no control on free flowing or closed. This way the only control system the 2nd turbo needs is just the pressure created from the primary turbo. I wasn't sure how this would affect other things in the engine so I posted on here before attempting.

Chris

Edit: attention to detail

7-sins

If that link won't work, type it in by hand

http://www.geocities.com/MotorCity/Garage/8255/vacroute_diag.gif

spooledUP7

7-sins! STOP! Don't disconnect the wastegate and preconrol solenoids! They are not simply a on off like you think. They are what you call a "duty cycle" which means the computer varies the timing between being on and off. If you unplug the harness to the solenoids you will cause the waste gate to force less air over the turbine causing less and less boost. This would not help things.

Here is your problem: I saved the text from an earlier post on the subject, and I think that it best describes more of what is happening.

Sequential Hell: The inability to discover, solve, and maintain problems within sequential turbocharger system.

(Note: The below is assuming that the primary turbo works in partial or if not in full function)

Suspect: Turbo Control Actuator (TCA)

Most of us have at one time or another discovered during our own personal journeys into “Sequential Hell” that it takes both boost and pressure to make the turbo control actuator move quick enough (or at all) to deflect exhaust gasses to the second turbo.
But how does that correlate to lack of boost from the secondary turbo?

Summary: The lack of significant boost means that the pressure side of the actuator will not be able to help much in moving that actuator’s arm without a good source of vacuum helping with the load of the exhaust and mechanical resistances.

Since the pressure that’s applied to the TCA is directly related to what the primary turbo boosts pre-4500 RPM, there would need to be at least 7.5-8 PSI created and stored in the pressure chamber (The black box on top of the motor) to push the TCA open.

There would also need to be at least 15” of vacuum supporting the pressure side of the TCA to quickly open the TCA door to the secondary turbo for quick boost up.

If there were a leak in either the pressure or the vacuum system leading to the TCA, you would need at least one of the two performing as per normal to slowly open the TCA.

If you have a leaking vacuum system between the vacuum chamber and the TCA and you only produced less than 7.5 PSI before reaching the crossover point, 4500 RPM then the TCA will not have enough energy from either the pressure of vacuum system to open the TCA.

So, by letting off the gas and getting back on it again you have ultimately charged the system just enough to open that door using the vacuum system, and then sustain it by the increased boost produced by the combination of the two turbos.

Make sense?

So, easiest thing to do is to test the system. Check to see that the Vacuum/Pressure chambers are not leaking, then the check valves, then the hoses connecting to the switching solenoids as well as to the actuator its self, and last but not least the actuator alone.

This testing goes pretty quick with the exception to testing the switching solenoid, but you can easily do it yourself.

Good luck

EugeneChoe

ok... if i get full vacumn at 19hg, does that mean i dont have a vacumn leak or could i still have one. i kinda have the same problem except i get only 5lbs of boost for my 2nd turbo.

7-sins

spooledUP7, thanks. I thought the solenoids were duty cycle like you said but my friend was stuck on a theory of them being either all the way off or all the way on.

I did suspect the TCA but my friend said he could see that actuator move from underneath the car when I reved WOT in neutral above 5k but less then redline. The two actuators we don't see moving are the turbo precontrol or the wastegate actuators. My vacuum chamber stores pressure, I pulled off one of the hoses going to it and it will release air. The once way check valve works fine because I tested that. Well it makes a whine noise when air is being blown in the one way and it blocks all the air off from the other way, I was guessing that is normal. I also tried to spool up to 11psi then let off the gas and after the vacuum drops back to 20, give it WOT again. The psi spooled right back up to 11psi but then dropped down to 0 after 5000 rpms.

EugeneChoe, You might want to check spooledUP7's post about yours because it sounds like your TCA is opening it just isn't opening enough

Chris

spooledUP7

7-sins, try looking at the hoses that connect the vacuum solenoid to the rat's nest, and then the hoses that connect from the rats nest to the down tubes that connect to the Turbo Controller. Also remember that the turbo controller isn't the only device that relies on the vacuum chamber tank . The Charge Control Actuator, and the Charge Reliefe Valve are also controled by a vacuum chamber. The The charge control actuator use both and pressure, and is the gate between your primary and secondary turbo. If there is a leak within these systems then you will be not have enough volume of vacuum to pull the TCA rod back. So, check them out too.

EugeneChoe

i dont know how to test these things. is it in the wookshop book. where can i take my car to test this. also the turbos were bought new 2 years ago could this mean their bad already??. how much would this cost to fix. thanks for all the help. im gonna go back and read the post over so i can understand it better. also is this the same reason i have trouble at transition. my boost pattern seems to be 8-5-5

3rdgenowner

spooledup7, your theory about the primary turbo having to make atleast 7.5 to 8 psi is correct, but I have an electronic boost controller from pfs, and I can make the first turbo boost up to 12 pounds on high and STILL no boost out of the second turbo. Any thoughts on that? But you are right, it does have to make a certain amount of boost for the TCA to work properly. My car is at PFS currently, so I will post what they find in a couple of days

7-sins

3rdgenowner, let me know what PFS finds. I had my car at a mechanic but he didn't have time to work on it so now it's back in my hands. I'm trying to get this done myself.

Chris

3rdgenowner

7sins, Hey man, well it might be awhile before I find out, I have to go out of town and it's gonna sit at PFS for about 2 more weeks..........DOH!!! Oh well, Im gettin the keypad as well and I told them to just make sure it runs perfect before I get it back so who knows what they will find. I miss my rex.....



Sorry to hear about you not gettin yours fixed, I was hopin you would so you could tell me what was wrong with it. The guy at PFS told me its probably just a vacuum leak. Well I dare him to find one, Ive already looked. But then again, they call themselves EXPERTS.......we'll see.

7-sins

Yeah PFS told me the same thing about the Vacuum Leak. "Well I dare him to find one, Ive already looked." sounds like me I looked hard as hell... didn't pull off the manifold though. I was talking to PFS about when I started my car why it smoked... they said it was normal as long as it goes away after 30 seconds. At the RX7 BBQ over the weekend I came to find out that I might be burning a little coolant. That doesn't sound to "normal" to me on a brand new engine. If KD Rotary wasn't in PA then I think my car would be up there already.

theman

7-sins you may want to take the manifold off add check the lines and all on the actuator there just in case.

EugeneChoe, that's a funny name for me because a friend of mine goes by that name. Anyway you might have some trouble with your vac lines to that same actuator under the upper manifold since that is for the second turbo boost up. I've had a couple come to me with the shitty second turbo boosting problem that had their vac lines done at PFS and the lines they put on were too long and kinked, it was a simple fix to get full boost back but the lines running to that actuator are crucial so it's just something that should be checked.

3rdgenowner

Hey 7sins, I talked to KDRotary as well, and they told me that it would probably be late september until they could look at it. But, unlike PFS, they said that it would probably take less then one day to fix and I could go up there and wait while they looked at it. Sounds to me like they wanted to help me more then PFS did. Ive noticed that if you dont have $$$$ they dont want to bother with ya. I get my car back next weekend and I will post what they find. I miss my car.....

7-sins

yeah man i know how you feel... I was w/o my car for 2 weeks. One week because my tailights were being converted to 99 J-spec and the other week because the mechanic had it. Feels so good when you get it back though even if it's not running 100%

3rdgenowner

7sins, Hey read my new post about PFS

spooledUP7

3rdgen,
Making boost on the primary is only one criteria that needs to be met for the secondary turbo to make boost. Having boost does nothing if the pressure is not making it's way to the turbo control actuator. Same goes for the Vacuum side of the Turbo Control Actuator. Both the Pressure and the Vacuum chamber could be holding, but if a hose, or solenoid is leaking, clogged, or unpluged then they do no good for the actuator.
I remember talking with Dave at KD and he told me of a time when he found a solid metal line plugged with rust. That would be a case of blockage. So, if you were able to move the turbo control actuator by applying direct vacuum and pressure then you have a good shot at fixing the problem for little money.
Trace the hoses from begining to finish, and test the switching solenoids on the way.

Also, this sounds stupid, but make sure the actuator is actually connected to the gate arm on the exhaust manifold. This goes for the wastegate and precontrol too.

Grizzly

My pal has basicly the same problem the Secondry Turbo does not produce any boost (or very little, 4psi) but the primary is (10-11 psi) the car is also blowing some blue smoke on cold start. Could this be the Turbo or the Turbo control Solenoid?

This car is beening looked at by a garage at the moment and they have picked up that the Air pump has failed could this be related? the car is modified ie PFC,Street port,3" Full Exhaust,Intakes etc. Would the air pump go due t a fault or is it cause by wear ?

Can anyone shead some light on this problem?