How can you tell if the twins are hesitating?
07-28-08, 11:52 PM
#1
How can you tell if the twins are hesitating?
Title pretty much says it all guys .. I dont know how to point out wat the problem in my car is... Sometimes i step on the gas and especially after a fast change of gears, i dont feel the turbo kicking in... and then when i let go of the gas i just hear this loud wooshing sound kinda like BOV but, shoot, i dont have one.
Is that what they say turbo hesitation is .. and if not what is turbo hesitation? and wat is the actual problem in my car and what should i do?
oh btw my car is a 93 base model and if anyone is still wondering yeah it is still totally stock.. oh well .. and its got about 75k miles on it ..
Thanks guys
Is that what they say turbo hesitation is .. and if not what is turbo hesitation? and wat is the actual problem in my car and what should i do?
oh btw my car is a 93 base model and if anyone is still wondering yeah it is still totally stock.. oh well .. and its got about 75k miles on it ..
Thanks guys
07-29-08, 06:44 PM
#3
well there is the thing i dont have a boost gauge so i dont really know...
the only thing i can tell is that sometimes it feels like the turbos do kick in but its like theyre spinning the opposite way or i dont know.. you dont feel it kicking in, you dont stick to the seat! you know wat im saying .. and then when i let go of the gas theres just that loud wooshh sound ..
its weird
the only thing i can tell is that sometimes it feels like the turbos do kick in but its like theyre spinning the opposite way or i dont know.. you dont feel it kicking in, you dont stick to the seat! you know wat im saying .. and then when i let go of the gas theres just that loud wooshh sound ..
its weird
07-30-08, 10:31 AM
#6
this is kinda worrying me now. And the worst thing is nobody arround my area works on rotary engines ... even the mazda dealership said they dont work in these cars so i dont know wat to do.
07-30-08, 10:59 AM
#7
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Read through some off the FAQs on this board, they are really helpfull in understanding what people here are talking about.
In short: a 10-8-10 transition refers to the amount of boost over the rev-range.
during acceleration the 2nd turbo only kicks in at 4500rpm, before that turbo 1 is generating 10 psi, when switching from turbo 1 to 2 boost will dip to about 8 psi, which should soon should be back up to 10psi when turbo 2 is fully working.
It seems that what you are describing it that turbo 2 isn't spooling as it should.
In short: a 10-8-10 transition refers to the amount of boost over the rev-range.
during acceleration the 2nd turbo only kicks in at 4500rpm, before that turbo 1 is generating 10 psi, when switching from turbo 1 to 2 boost will dip to about 8 psi, which should soon should be back up to 10psi when turbo 2 is fully working.
It seems that what you are describing it that turbo 2 isn't spooling as it should.
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07-30-08, 11:00 AM
#8
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stay away from mazda they will do more harm then good! I suggest you get a boost gauge to further determine what is going on.
The 10-8-10 transition is the stock twins boost pattern. The first turbo spools up to 10 psi then at 4500 rpms the it drops to 8 psi to spool the other turbo then they both come online at 10 psi. So that is where you get the 10-8-10.
Also check the intercooler piping they are known to crack when older which will not let your turbos build pressure.
The 10-8-10 transition is the stock twins boost pattern. The first turbo spools up to 10 psi then at 4500 rpms the it drops to 8 psi to spool the other turbo then they both come online at 10 psi. So that is where you get the 10-8-10.
Also check the intercooler piping they are known to crack when older which will not let your turbos build pressure.
07-30-08, 05:35 PM
#10
i agree you NEED a boost gauge to figure out anything with the car. The car should have a BOV if its stock, if it truelly does not have a BOV then you have a boost leak. Even with a BOV you may have a boost leak, so you should start looking at all the couplers and the rubber accordion pipes for cracks or loose fits.
Turbo hesitation is usually refered to as lag. If your car is running the stock sequential twins you really dont have much lag to speak of. so you should feel the turbos kicking in especially if you're getting on the car and are above about 3000 rpms. You might have a problem in the rats nest causing the boost to drop off after the second turbo is supposed to kick in
Turbo hesitation is usually refered to as lag. If your car is running the stock sequential twins you really dont have much lag to speak of. so you should feel the turbos kicking in especially if you're getting on the car and are above about 3000 rpms. You might have a problem in the rats nest causing the boost to drop off after the second turbo is supposed to kick in
07-30-08, 06:28 PM
#11
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i kind of have the same problem. and it started very recently. lets say im in first at about 1/4th throttle.....and i step on the gas all of a sudden, boost touches 5 psi and comes down to 0. i shift to 2nd and i get 10, the rest of the gears are fine.
BUT if im in first and i tap the accelator a few times before i let go of the clutch..it boosts fine! whats the deal here? and i kinda know what noise your talking about...ive taken my BOVs pipe out soo the woosh is pretty clear. but the noise scamil87 is talking about is more of a UUMPBH!
BUT if im in first and i tap the accelator a few times before i let go of the clutch..it boosts fine! whats the deal here? and i kinda know what noise your talking about...ive taken my BOVs pipe out soo the woosh is pretty clear. but the noise scamil87 is talking about is more of a UUMPBH!
07-30-08, 08:08 PM
#12
i kind of have the same problem. and it started very recently. lets say im in first at about 1/4th throttle.....and i step on the gas all of a sudden, boost touches 5 psi and comes down to 0. i shift to 2nd and i get 10, the rest of the gears are fine.
BUT if im in first and i tap the accelator a few times before i let go of the clutch..it boosts fine! whats the deal here? and i kinda know what noise your talking about...ive taken my BOVs pipe out soo the woosh is pretty clear. but the noise scamil87 is talking about is more of a UUMPBH!
BUT if im in first and i tap the accelator a few times before i let go of the clutch..it boosts fine! whats the deal here? and i kinda know what noise your talking about...ive taken my BOVs pipe out soo the woosh is pretty clear. but the noise scamil87 is talking about is more of a UUMPBH!
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/weird-boost-issue-341534/
It fairly similar to what you described.
07-31-08, 12:58 AM
#14
this is the exact reason why browsers were made with a "favorites"/"Bookmarks" toolbar/folder.
it could be that the sequential system has a problem with it somewhere. the VERY LAST thing that the problem could be, is the turbos' are bad, but with your symptoms its hardly the case.
check all your piping and couplers, GET A BOOST GAUGE, and we can go from there.
it could be that the sequential system has a problem with it somewhere. the VERY LAST thing that the problem could be, is the turbos' are bad, but with your symptoms its hardly the case.
check all your piping and couplers, GET A BOOST GAUGE, and we can go from there.
07-31-08, 09:08 AM
#15
FearNoPiston, generally, I'll either remember a user having or fixing a similar issue. So when I do a search, I can greatly narrow the scope to find the right thread by including the username. In this case, I knew Dave Disney had done a lot of troubleshooting around the TCA operation. His symptoms were very similar to the post above, so I just search for threads started by Dave's forum name.
07-31-08, 11:27 AM
#16
Oh yeah i knew wat the 10-8-10 was .. i just didnt know wat the term actually was ... im gonna get a boost gauge to figure out what this thing is ..
And the threads you guys sent are different problems . Theyre all related to PFC lag issues and its not my case. I dont even have a PFC. Thanks anyways tho.
And the threads you guys sent are different problems . Theyre all related to PFC lag issues and its not my case. I dont even have a PFC. Thanks anyways tho.
07-31-08, 11:33 AM
#17
For your issue, you need:
1. Boost gauge
2. Work through the troubleshooting guide:
http://www.autosportracetech.com/RX-...leshooting.htm
You can't do anything until you have a boost gauge.
07-31-08, 11:35 AM
#18
i kind of have the same problem. and it started very recently. lets say im in first at about 1/4th throttle.....and i step on the gas all of a sudden, boost touches 5 psi and comes down to 0. i shift to 2nd and i get 10, the rest of the gears are fine.
BUT if im in first and i tap the accelator a few times before i let go of the clutch..it boosts fine! whats the deal here? and i kinda know what noise your talking about...ive taken my BOVs pipe out soo the woosh is pretty clear. but the noise scamil87 is talking about is more of a UUMPBH!
BUT if im in first and i tap the accelator a few times before i let go of the clutch..it boosts fine! whats the deal here? and i kinda know what noise your talking about...ive taken my BOVs pipe out soo the woosh is pretty clear. but the noise scamil87 is talking about is more of a UUMPBH!
07-31-08, 11:37 AM
#19
The thread I linked was for someone else. However, it has nothing to do with the PFC but the TCA which is outside of the ECU.
For your issue, you need:
1. Boost gauge
2. Work through the troubleshooting guide:
http://www.autosportracetech.com/RX-...leshooting.htm
You can't do anything until you have a boost gauge.
For your issue, you need:
1. Boost gauge
2. Work through the troubleshooting guide:
http://www.autosportracetech.com/RX-...leshooting.htm
You can't do anything until you have a boost gauge.
07-31-08, 12:27 PM
#20
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Sorry I have too....
Hello
Sorry, I have to do this.
You'll know if the Twins are hesitating if you cant even get to third base with both of them after a few dates.
I know its lame but could not resist after my long week.
Max
Sorry, I have to do this.
You'll know if the Twins are hesitating if you cant even get to third base with both of them after a few dates.
I know its lame but could not resist after my long week.
Max
07-31-08, 05:13 PM
#21
ya'll arent the only 2 experiencing this problem, in fact most everyone that has the sequential twins will at some point experience this or something similar. the problem is, its not just a simple "oh this is what needs replaced". The twins are very complex and have a miles worth of vacuum hoses that can fail, several solenoids and vacuum chambers that are all vital to keeping the boost up. If anyone of them fails you have little power in some portion of your powerband. The only way to fix it is to check over everything that has to do with the turbo control system, and its a big confusing mess of a system.
06-01-09, 10:22 PM
#22
Check this thread:
https://www.rx7club.com/showthread.php?t=341534
It fairly similar to what you described.
https://www.rx7club.com/showthread.php?t=341534
It fairly similar to what you described.
I am definitely experiencing similar issues (that Dave had) and his logic is sound. I'm going to look into replacing the TCA. I noticed Pettit sells a "blueprinted" version of this, is it worth it versus OEM replacement?
06-02-09, 11:46 AM
#23
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Im another one to join in with the same problem. I know whats happening because ive watched my boost gauge i accelerate in a gear really quickly but not to redline, then change gear quickly. Now when i throttle the boost gauge only goes to about 5/6 psi and the exaust note changes (the turbos are still running in twin mode and not switching back to the first turbo on it own).
Ive got upgraded solenoids, and ive replaced the 1 way check valves and the pressure and vacuume chambers are all air tight, i know that the turbo control actuator is staying open for some reason,, maybe its sticking open???
The only other thing i would like to point out is maybe its my driving style,, maybe im just getting to 4250rpm (twin mode) then changing gear and im not dropping below 3000rpm so im still in twin mode but with a low rpm so a very slow spool up?
Can the switch back from twin to single be altered using the power fc,, could i make it 3800 rpm or something? any experiences?
Ive got upgraded solenoids, and ive replaced the 1 way check valves and the pressure and vacuume chambers are all air tight, i know that the turbo control actuator is staying open for some reason,, maybe its sticking open???
The only other thing i would like to point out is maybe its my driving style,, maybe im just getting to 4250rpm (twin mode) then changing gear and im not dropping below 3000rpm so im still in twin mode but with a low rpm so a very slow spool up?
Can the switch back from twin to single be altered using the power fc,, could i make it 3800 rpm or something? any experiences?
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