3rd Generation Specific (1993-2002) 1993-2002 Discussion including performance modifications and Technical Support Sections.

Engine cut out at 110-120 MPH

Old 01-27-19, 12:38 PM
  #1  
Junior Member
Thread Starter
 
Join Date: May 2018
Location: California
Posts: 31
Liked 0 Times in 0 Posts
Engine cut out at 110-120 MPH

Hi,

I'm having a weird problem that I'm not sure how to diagnose. When I drive my car, 93 rx7, 13b some piggyback tune, rebuild ~8k miles ago, 7psi boost because pills are missing, it pulls what I would classify as fine every gear to redline except 4th (and I would assume 5th but haven't checked). When I get to about 120ish MPH (somewhere around 5.5k-6.5k rpm) the engine seemingly cuts out (ie car starts slowing down, boost drops to vacuum, aux systems stay on no engine light) until I lift my foot off the gas and continue to push it where it comes back "alive" and continues pulling. I didn't take it up as high in speed after it cut out because I was worried about it. Any ideas on what this could be?

Thanks
Cloveh is offline  
Old 01-27-19, 03:39 PM
  #2  
Junior Member
 
97fd3s's Avatar
 
Join Date: Aug 2016
Location: London
Posts: 44
Liked 1 Time in 1 Post
Is it a JDM car? Speed limiter at 112mph or 108mph cant remember exactly.
Early cars have a wire you can cut 96+ models do not.
97fd3s is offline  
Old 01-27-19, 04:35 PM
  #3  
Junior Member
Thread Starter
 
Join Date: May 2018
Location: California
Posts: 31
Liked 0 Times in 0 Posts
No its a U.S. 93 Touring. I am worried it could be a fuel cut/fuel pump issue but I have never experienced one before so don't know what I am looking for.
Cloveh is offline  
Old 01-28-19, 07:52 AM
  #4  
RX-7 Bad Ass
iTrader: (52)
 
DaleClark's Avatar
 
Join Date: Jan 2002
Location: Pensacola, FL
Posts: 11,158
Liked 270 Times in 230 Posts
Is it a JDM car? I know some Japanese cars had speed cuts where they would cut out past a certain speed. Or maybe a Japanese ECU in the car.

Dale
DaleClark is offline  
Old 01-28-19, 08:50 AM
  #5  
Rotary Enthusiast
 
Join Date: Jul 2001
Location: JAX, FL
Posts: 1,290
Liked 26 Times in 25 Posts
It sounds like a speed cut or boost cut. You say you have a "piggyback tune" is it a modified factory ecu, or something else?
AE_Racer is offline  
Old 01-28-19, 09:23 AM
  #6  
Junior Member
Thread Starter
 
Join Date: May 2018
Location: California
Posts: 31
Liked 0 Times in 0 Posts
I believe it is a modified factory ecu.
Cloveh is offline  
Old 01-28-19, 09:32 AM
  #7  
gross polluter
iTrader: (2)
 
Tom93R1's Avatar
 
Join Date: Mar 2001
Location: Tempe, AZ
Posts: 1,711
Likes: 0
Liked 5 Times in 5 Posts
Is it cutting out pretty hard like the ignition can't fire spark plug or it is just that the boost drops off and you don't have enough power to push past 120?
Tom93R1 is offline  
Old 01-28-19, 09:36 AM
  #8  
Rotary Enthusiast
 
Join Date: Jul 2001
Location: JAX, FL
Posts: 1,290
Liked 26 Times in 25 Posts
Originally Posted by Cloveh View Post
I believe it is a modified factory ecu.
Could it be a JDM ECU?
AE_Racer is offline  
Old 01-28-19, 10:01 AM
  #9  
RX-7 Bad Ass
iTrader: (52)
 
DaleClark's Avatar
 
Join Date: Jan 2002
Location: Pensacola, FL
Posts: 11,158
Liked 270 Times in 230 Posts
^That's my guess. Many of the chipped ECU's are from Japan. The part number on the front of the ECU should give a clue.

May also be worth finding a US ECU that you can borrow to test the theory out. Most other problems (fuel, ignition, etc.) would manifest itself in any gear or speed.

It could also be fuel cut from too much boost, are you certain the boost isn't creeping up and is staying low?

Dale
DaleClark is offline  
Old 01-28-19, 11:10 AM
  #10  
Junior Member
Thread Starter
 
Join Date: May 2018
Location: California
Posts: 31
Liked 0 Times in 0 Posts
I don't think its a JDM ECU, I believe it could go past 120 I just needed to pull my foot off the gas and put it back on. I have newer cars where I have hit the speed limiter and it keeps the speed but just doesn't go any faster. This is like removing my foot completely from the gas pedal and slowing down via engine vacuum. I don't remember much else, but I confidently remember the boost falling to vacuum on my boost gauge when this happened.
Cloveh is offline  
Old 01-28-19, 11:15 AM
  #11  
Junior Member
Thread Starter
 
Join Date: May 2018
Location: California
Posts: 31
Liked 0 Times in 0 Posts
I just got new spark plugs like 700 miles ago and SP wires(the old ones were arcing), it felt like a pretty hard cut out, I don't have experience with ignition cutouts, but this could have been that? It doesn't happen in any other gear though which is curious.
Cloveh is offline  
Old 01-28-19, 01:38 PM
  #12  
RX-7 Bad Ass
iTrader: (52)
 
DaleClark's Avatar
 
Join Date: Jan 2002
Location: Pensacola, FL
Posts: 11,158
Liked 270 Times in 230 Posts
You're going to need to look and rule out the JDM ECU thing. Remember, this is an ECU that was designed in the late '80s, the speed cut (and the fuel cut) is not smooth and easy, it's harsh.

If it was plugs, fuel pump, etc. you would notice this in any gear.

Also, please be safe!

Dale
DaleClark is offline  
Old 01-28-19, 01:51 PM
  #13  
Don't worry be happy...
iTrader: (1)
 
Montego's Avatar
 
Join Date: Apr 2001
Location: San Diego, CA
Posts: 6,414
Liked 71 Times in 55 Posts
Originally Posted by DaleClark View Post
You're going to need to look and rule out the JDM ECU thing.
Yep! Don't assume, verify instead.

Cloveh,

It takes five minutes to check. Open the kick panel and look at what you have.
Montego is offline  
Old 01-29-19, 10:28 AM
  #14  
Junior Member
Thread Starter
 
Join Date: May 2018
Location: California
Posts: 31
Liked 0 Times in 0 Posts
Ok so I pulled the kick panel, what is the difference between the JDM and USDM ecus?
Cloveh is offline  
Old 01-29-19, 10:58 AM
  #15  
RX-7 Bad Ass
iTrader: (52)
 
DaleClark's Avatar
 
Join Date: Jan 2002
Location: Pensacola, FL
Posts: 11,158
Liked 270 Times in 230 Posts
Take a picture of the ECU and post it up.

Dale
DaleClark is offline  
Old 01-29-19, 10:59 AM
  #16  
Rotary Enthusiast
 
Join Date: Jul 2001
Location: JAX, FL
Posts: 1,290
Liked 26 Times in 25 Posts
Look at the big number, N3A1, N3A7 etc
AE_Racer is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
dothacker
2nd Generation Specific (1986-1992)
64
07-28-07 12:48 PM
teddyrx2
Old School and Other Rotary
21
11-25-06 06:08 PM
ArchangelX
3rd Generation Specific (1993-2002)
5
07-25-05 11:31 PM
Parastie
2nd Generation Specific (1986-1992)
3
07-26-04 09:40 PM


Thread Tools
Search this Thread
Quick Reply: Engine cut out at 110-120 MPH


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.