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wraith 10-16-2003 06:43 PM

i've spent the last week doing changing over to silicone vac lines, and i finished tonight. it ran pretty good, but still had the 3psi of boost after 4500RPM. so i figured oh well. well, the test run was fine, and on the way to my brothers soccer game it was fine. i start my car start driving and i hit the main road, and 0psi...THAT ******* RIGHT ONLY ******* 0 PSI!!!!!!!!! https://www.nopistons.com/forums/pub...1047683454.gif https://www.nopistons.com/forums/pub...1047683358.gif

https://www.nopistons.com/forums/pub...1047683358.gif so i get to the last street to my house drive slow will windows down and there is 0 boost leaking. i get inside, and rip off the UIM and there is not one NOT ******* ONE line loose.



so what the **** now guys. i love my car but if i could find the sadistic worthless mazda **** that designed that sequential system i would kill him and all blood relatives. i'm so close to being ******* done that i don't even want to look at the car. are there any ideas please help.

Dumbrotorkid 10-16-2003 07:53 PM

maybe go non-seq??or single???ive had numerous probs with the seq..and guess how many ive had with non..none

just my opinion

turbovr6 10-16-2003 08:09 PM

unfortunatly there are atleast 20 things tht could have gone wrong. Honestly the only easy way is get rid of all that crap.

Going single was the best decision I ever made.



Did you check all the intake pipes/hoses/couplers? The rubber coulplers love to break, sometimes you can't see the problem unless you grab the pipes and flex them to find the leak. If it's not that, and you are sure all the hoses are on correctly, you may have a bad solinoid. Just cuz the check engine light does'nt come on, does'nt mean everything is working properly

RX73rdgen 10-16-2003 08:14 PM

Hmmm... maybe one of your lines in pinched or misrouted. Or maybe a solenoid is bad.

JimmyJimboJet 10-16-2003 08:28 PM

have you always had boost problems with the car? my buddy had the lower rubber coupling on the intercooler rip, resulting in a gradual boost loss.

wraith 10-16-2003 09:21 PM


Originally Posted by JimmyJimboJet' date='Oct 16 2003, 05:28 PM
have you always had boost problems with the car? my buddy had the lower rubber coupling on the intercooler rip, resulting in a gradual boost loss.

this is the only coupling that i havn't checked. that sounds like a possibility, but i don't know if it would cause absolutly no boost, with no sounds of a leak at all. i'm so lost. i'm just gonna wait until i have enough cash to go single.......god damn that's gonna be a while.... figure 1k for ECU, 2800k for turbo kit, and what another 1.5k for fuel and various other ****.

vosko 10-16-2003 09:28 PM

TCA thingy popped off

RX7tuner 10-17-2003 12:38 AM

Assuming the turbos are still working, I would think you have a leak somewhere in your intake piping. Your turbos would sound a little louder than normal also. To check you need to take off each of the couplings and inspect them very carefully. Usually one of them gets a cut in it and you cannot tell without taking them all out and bending them and checking for splits. Assuming a minor problem in the sequential system, and no leaks in the intake piping, you should still get some sort of boost, at least a few lbs. It could be a possiblity your turbos are shot. maybe they arent producing any boost. Not sure how you would check for that, but maybe the compressor wheel is busted or something. Just a thought. I had never ending sequential problems in my 93, and just went non-sequential. Never had a problem since(for 2 years), and I am much happier with the reliability of the turbos I get from running non-sequential.

jspecracer7 10-17-2003 06:06 AM

sounds like someone needs to go non-sequential...or better yet, go single turbo

Danno 10-17-2003 10:18 AM

Do you have the stock BOV and CRV on your car? I was loosing boost because of the rubber pipes that fit on the turbos that go to the CRV and BOV because they were broken. The heat from the turbos dry rotted the rubber tubes and cracked them. You might want to check those.

PhoenixDownVII 10-17-2003 01:07 PM


Originally Posted by wraith' date='Oct 16 2003, 07:43 PM
i love my car but if i could find the sadistic worthless mazda **** that designed that sequential system i would kill him and all blood relatives. i'm so close to being ******* done that i don't even want to look at the car. are there any ideas please help.

I guess this explains your SN "Wraith" https://www.nopistons.com/forums/pub...DIR#>/wink.png



Go non-seq or single bro....they call it a "rats nest" for a reason..i think. lol

ccarlisi 10-19-2003 10:26 AM

1. If you have a problem with your wastegate control you will be limited to the spring pressure=7psi. Since you can't get any boost above 4500 we can rule out the wastegate control system.



2. If you are getting ZERO psi in secondary mode you must be vented boost out of the system.



3. Since you're getting boost in the primary mode the leak must only be present in secondary mode. Based on this you can rule out the AIR BYPASS VALVE and everything that is associated with the primary turbo.



4. The only thing on the secondary turbo that could dump all the pressure the primary and secondary turbo are making is the CRV valve. This valve is positioned on the section of the Y pipe closest to the firewall. Remember the Y-pipe is connected to the exhaust outlet of each turbo. The charge control valve blocks off the rear turbo's section of the pipe when the car is in primary only and primary prespool mode. However, when the secondary turbo is prespooling it generates air pressure in rear section of the Y-pipe. If this area was completely sealed the secondary turbo would not be able to spin freely because it would be blowing air into a closed container. This problem is overcome by using a second valve (CRV) on the 2nd turbo's section of the y-pipe to vent the boost the secondary turbo makes out into the atmosphere. When you switch from primary prespool to secondary mode the CHARGE CONTROL VALVE opens and the CRV closes, redirecting air from the CRV through the CCV and up to the IC.



5. Therefore if you really only have this problem in secondary mode it is due to

---A. a problem with the CRV control system (trace the lines)

---B. a problem with the CRV itself

---C. a leak in the rubber elbow between the CRV and the Y pipe

yellowspeedracer 10-19-2003 01:00 PM

first of all i know dick about these cars. but to check for boost leaks on a piston motor, get a 2.5" exhaust pipe and weld one end closed with a fitting that goes to an air compressor. the clamp that pipe to the hose that comes off the airbox and into the turbo. then turn on the compessor and you should be able to hear any leaks in the piping. on a piston engine some air will leak into the motor through the valves...i dunno about rotary.



also your WG may be stuck open. when there's a lot of carbon build up this can happen.



good luck

DUB 10-20-2003 08:22 AM


Originally Posted by wraith' date='Oct 16 2003, 03:43 PM
i love my car but if i could find the sadistic worthless mazda **** that designed that sequential system i would kill him and all blood relatives.

give the poor bastards a break...it is the first production car to have a seq. turbo sys.



Call me crazy, but I might be converting back...Already started piecing parts together...



Do I miss the https://www.nopistons.com/forums/pub...1047683358.gif ??? dunno

wraith 10-20-2003 02:50 PM


Originally Posted by ccarlisi' date='Oct 19 2003, 07:26 AM
Since you can't get any boost above 4500 we can rule out the wastegate control system.

dude i'm getting not boost at all. zip, zilch, nadda. absolutely none.

wraith 10-20-2003 02:51 PM


Originally Posted by vosko' date='Oct 16 2003, 06:28 PM
TCA thingy popped off

https://www.nopistons.com/forums/pub...1047683561.gif can you explain

ccarlisi 10-20-2003 08:33 PM


Originally Posted by wraith' date='Oct 16 2003, 03:43 PM
it ran pretty good, but still had the 3psi of boost after 4500RPM. so i figured oh well. well, the test run was fine, and on the way to my brothers soccer game it was fine. i start my car start driving and i hit the main road, and 0psi...THAT ******* RIGHT ONLY ******* 0 PSI!!!!!!!!! https://www.nopistons.com/forums/pub...1047683454.gif https://www.nopistons.com/forums/pub...1047683358.gif

https://www.nopistons.com/forums/pub...1047683358.gif so i get to the last street to my house drive slow will windows down and there is 0 boost leaking.



How can you tell there is ZERO boost leaking? Can you hear the turbo(s)?



Does the car sound louder than usual?



SEQUENTIAL SYSTEM:

The TCA is the big fat actuator on the bottom of the turbo mani. I don't think that's the problem, unless there is more than one problem. If the TCA is stuck in primary mode you would get normal boost below 4500 and the power curve would flatten out above 4500. If it is stuck in secondary mode you would get boost above but not below 4500.



Similarly if the charge control actuator (CCA) is stuck in primary mode you would get normal boost below 4500 and the power curve would flatten out above 4500. if the cca was stuck in secondary mode you would get zero or next to no boost below 4500 and normal boost above.



As I said before, if the CRV is stuck open you will get little or no boost above 4500 but have normal boost below that point.



That is all there is to the sequential system. I don't think that's the source of your problem.



WG CONTROL:

if you disconnect the WG solenoids to both turbos you will still get 7psi on the primary turbo. If you forget to connect the vac lines going from the turbos to the WG actuators you will get way too much boost.



Since you don't have either symptom you can rule this system out as well.



BOV:

If the BOV is stuck open you will bleed off boost at all rpms. You would still be able to hear the turbos because they would still be getting exhaust pressure. If you have the BOV disconnected from the stock airbox, you should also hear a loud hissing noise.



COUPLERS:

Obviously, if there is a cut at any point in the piping from the turbos to the throttle body you would lose boost all the time.



THEREFORE, focus on these last two items until you start seeing boost at some part of the RPM range. The fact that you said you initially saw 3psi seems to indicate there was some kind of leak and it got worse.

vosko 10-20-2003 09:09 PM

TCA = Turbo control actuator



it controls the flapper that makes the secondary turbo come online



if you lay under your car. you will see it on the bottom. possibly the c-clip fell off and rod popped off

wraith 10-21-2003 07:40 AM


Originally Posted by ccarlisi' date='Oct 20 2003, 05:33 PM
How can you tell there is ZERO boost leaking? Can you hear the turbo(s)?



Does the car sound louder than usual?

i've had boost leaks before, and i hear absolutely no leaking. i can't hear any spool from the turbo's either. the car sounds exactly the same as before. and i checked all the pre-control rod and the wastegate rod, and the c-clamps are still on. im beginning to get the feeling that they died. https://www.nopistons.com/forums/pub..._DIR#>/sad.png

DUB 10-21-2003 01:18 PM

don't think they just died from a hose job.

r0gu3 10-22-2003 12:52 AM

I had similar problems and it was fixed by replacing a check valve.

Cooper 10-23-2003 03:02 AM

Check your double throttle control. If this isn't working properly it will limit your boost to under 5 psi.


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