2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

My turbo bogs down at higher RPM, then picks up again

Old Feb 19, 2005 | 09:40 AM
  #1  
ntempleton's Avatar
Thread Starter
Junior Member
Tenured Member 05 Years
 
Joined: Feb 2005
Posts: 9
Likes: 0
From: Mid Eastern
My turbo bogs down at higher RPM, then picks up again

I have heard that I have a poor grounding and need to reground my car. I have just recently upgraded the stock air box to a cone intake. Everything else is essentially stock. Is it possible that I need to buy a boost controller, because the stock part believes that the car is getting too much air so it slows the engine down temporarlily? Or do you believe that I need to simply reground my vehicle?
By the way, this happens on my 88 TII, and it only happens when I am accelerating hard at higher RPMS, anywhere from 3900 to 6500.
Reply
Old Feb 19, 2005 | 09:51 AM
  #2  
steve0178's Avatar
rx7 enthusiast
Tenured Member 10 Years
 
Joined: Oct 2004
Posts: 313
Likes: 0
From: cincinnati
a similar thing happend to me in my 300zxtt. It would pull hard then just die. It ended up being a boost leak under the intake manifold. Did you check all your boost lines for cracks/splits?
Reply
Old Feb 19, 2005 | 09:58 AM
  #3  
nfs05's Avatar
RB all the way
Tenured Member 10 Years
 
Joined: May 2002
Posts: 814
Likes: 0
From: canada, ottawa
check to see if your intake piping isnt collapsing under boost, ill bet you its that
Reply
Old Feb 19, 2005 | 01:59 PM
  #4  
ntempleton's Avatar
Thread Starter
Junior Member
Tenured Member 05 Years
 
Joined: Feb 2005
Posts: 9
Likes: 0
From: Mid Eastern
Ok i will try that, but I think my piping is fine, since I replaced so much of it recently anyway (many of the rubber pipes seemed to have been dried to hell). Any other suggestions?
Reply
Old Feb 19, 2005 | 04:35 PM
  #5  
Snrub's Avatar
Eats, Sleeps, Dreams Rotary
Tenured Member 15 Years
iTrader: (1)
 
Joined: Jun 2001
Posts: 3,106
Likes: 0
From: London, Ontario, Canada
Originally Posted by ntempleton
I have just recently upgraded the stock air box to a cone intake. Everything else is essentially stock. Is it possible that I need to buy a boost controller, because the stock part believes that the car is getting too much air so it slows the engine down temporarlily? Or do you believe that I need to simply reground my vehicle?
By the way, this happens on my 88 TII, and it only happens when I am accelerating hard at higher RPMS, anywhere from 3900 to 6500.
The answer to your question is no, you don't need a special boost controller. Did you mean "boost sensor," it is possible that is malfunctioning. It sounds like you're getting what we tend to generically refer to as hesitation. Intake/exhaust mods can cause your boost to increase because the stock wastegate is not able to vent off enough exhaust to control the boost. If your boost hits 8.6psi the ECU will cut fuel to the rear rotor. Has your exhaust been changed in any way? I'd be surprised if an intake alone is causing that much of a boost increase. The solution is either to port the wastegate or get a fuel cut defensor (FCD) and probably add fuel, depending upon how high your boost is.

Did your car suffer from hesitation before you changed the intake? If so then you're probably not hitting fuel cut. A common cause of this problem can be the TPS. You will want to test to see if it meets the properly WOT and no throttle condidions, but also check the sweep of motion (slowly and steadily) to ensure that it occurs smoothly. To do the later you will need a digital multimeter or an oscilloscope.

Last edited by Snrub; Feb 19, 2005 at 04:39 PM.
Reply
Old Feb 20, 2005 | 01:22 PM
  #6  
ntempleton's Avatar
Thread Starter
Junior Member
Tenured Member 05 Years
 
Joined: Feb 2005
Posts: 9
Likes: 0
From: Mid Eastern
yes the exhaust has been upgraded, but im not so sure how much because i didnt do it. the previous owner upgraded the exhaust before i got it. No my car did not suffer from hesitation before i changed the intake. would getting a boost controller help, because i would be able to tune the boost down?-of course i really wouldnt like to fix the problem going this route because that would tune my performance down.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Kyo
2nd Generation Specific (1986-1992)
6
Apr 13, 2019 09:24 AM
mazdaverx713b
Build Threads
48
Apr 21, 2016 06:45 AM
CaptainKRM
2nd Generation Specific (1986-1992)
14
Aug 26, 2015 09:52 PM
Alan777
3rd Generation Specific (1993-2002)
1
Aug 13, 2015 02:47 AM
baconflavored
SE RX-7 Forum
0
Aug 12, 2015 12:07 AM


Thread Tools
Search this Thread

All times are GMT -5. The time now is 12:15 PM.