Boost Problems...Please help.
#1
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Boost Problems...Please help.
My mods are intake, dp, mp, cb, pfb. 93rx7 on stock twins.
I set my pfb boost at 10psi. It pulls solid 10 all the way to redline in every gear in my numerous encounters.
PROBLEM
One night after a run in with another car, my boost suddenly died. I pulled over and shut off my motor. Fifteen minutes later, I started her up. Took her out for a spin and noticed my boost would not past 5 psi. The next day I disconnected my profec B, and returned it to the stock boost setup. When the first turbo kicks in, I get 7psi, then the second turbo kicks in, which increases it to 10 psi, but as soon as I hit 5500-6000rpms, boost will drop to either 0 or 5 psi only. If I connect her back to the pfb, I get the same results.
Today, I removed all hardware to reach both sides of the turbos. I proceeded to spin both of the turbo fins with my finger, and they are smooth and quiet. I checked all the hoses and they appear to be fine, no cracks.
What can be wrong with my Rex???
What should I check???
My turbos couldn't be bad, could it???
My car idles and drives fine but I can't get the boost up.
I'll be working on her for the next couple of days so I'll appreciate any advise you guys can give me.
I set my pfb boost at 10psi. It pulls solid 10 all the way to redline in every gear in my numerous encounters.
PROBLEM
One night after a run in with another car, my boost suddenly died. I pulled over and shut off my motor. Fifteen minutes later, I started her up. Took her out for a spin and noticed my boost would not past 5 psi. The next day I disconnected my profec B, and returned it to the stock boost setup. When the first turbo kicks in, I get 7psi, then the second turbo kicks in, which increases it to 10 psi, but as soon as I hit 5500-6000rpms, boost will drop to either 0 or 5 psi only. If I connect her back to the pfb, I get the same results.
Today, I removed all hardware to reach both sides of the turbos. I proceeded to spin both of the turbo fins with my finger, and they are smooth and quiet. I checked all the hoses and they appear to be fine, no cracks.
What can be wrong with my Rex???
What should I check???
My turbos couldn't be bad, could it???
My car idles and drives fine but I can't get the boost up.
I'll be working on her for the next couple of days so I'll appreciate any advise you guys can give me.
#3
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If you have checked for popped off vaccum hoses and boost leacks (specifically, the y-pipe coupler), then maybe a solenoid is broken. Check here for lots of info on troubleshooting boost problems:
http://www.autosportracetech.com/RX-7/rx7stuff.htm
Good luck.
http://www.autosportracetech.com/RX-7/rx7stuff.htm
Good luck.
#4
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I have a VR 93 FD. I just found out via my turbo boost gauge that my second turbo is not kicking in after the first one engages. I know that the pattern should be close to 10-8-10 but it's like 10-8-4. everything is stock except dp, aluminum ast. I'm checking the vacuum lines but are there any other possibilities? I appreciate all the help. Thanks. Em
#6
Rotary Enthusiast
you should indeed check around the y-pipe there is also a valve there that i have seen sometimes get stuck closed also check the two selenoids for turbo control and pre-control they are the two that bolt on to youre intake manifold
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Just finished my car last night and took her for a ride. Wow, I've forgotten how fast this car was, boosting perfectly all threw the rpms.
The culprit, you ask? It was the 3" rubber hose connecting the y-pipe. It had a two inch slash above the clamp.
I couldn't believe this was the problem when I initially discovered it. So I basically took apart my motor and tested all the selonoids with a vacuum pump.
Well I learn a little more about the car.
To everyone who has eractic boost, sereiouly, you must first take out all those stock 3" rubber hoses (air box hoses, intercooler hoses and the y-pipe hose, etc) and squeeze them because it very difficult to check for cracks when they are still on your car.
I'm sure I be back with more issues in time since my 7 is 10 years old. But truly, I thank those who've responded with possible solutions.
The culprit, you ask? It was the 3" rubber hose connecting the y-pipe. It had a two inch slash above the clamp.
I couldn't believe this was the problem when I initially discovered it. So I basically took apart my motor and tested all the selonoids with a vacuum pump.
Well I learn a little more about the car.
To everyone who has eractic boost, sereiouly, you must first take out all those stock 3" rubber hoses (air box hoses, intercooler hoses and the y-pipe hose, etc) and squeeze them because it very difficult to check for cracks when they are still on your car.
I'm sure I be back with more issues in time since my 7 is 10 years old. But truly, I thank those who've responded with possible solutions.
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