89 rx7 goes from start to redline - RX7Club.com - Mazda RX7 Forum

New Member RX-7 Technical Post your first technical questions here, in an easy flame free environment, before jumping into the main technical sections.

89 rx7 goes from start to redline

Reply

 
 
 
Old 09-06-14, 11:31 PM
  #1  
Junior Member
Thread Starter
 
Join Date: Sep 2014
Location: Gillette wy
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
89 rx7 goes from start to redline

Ok so here's the deal. Every time I start my 89 rx7 non turbo it goes immediately to full throttle...at least it seems...screaming to redline before i have to shut it down. It seems to be running smooth enough, but I can leave it running long enough to really tell. Anyone have any ideas?
Diamondsnake13 is offline  
Reply With Quote
Old 09-07-14, 02:55 AM
  #2  
Retired Moderator, RIP
iTrader: (142)
 
misterstyx69's Avatar
 
Join Date: Sep 2005
Location: Smiths Falls.(near Ottawa!.Mapquest IT!)
Posts: 25,758
Thanks: 0
Thanked 89 Times in 80 Posts
check your throttle cable and your plates in your throttle body to make sure they are free and not being yanked wide open.
misterstyx69 is offline  
Reply With Quote
Old 09-07-14, 12:41 PM
  #3  
Moderator
5 Year Member
 
Join Date: Jun 2005
Location: tulsa,ok.
Posts: 11,738
Thanked 2 Times in 2 Posts
And make sure the cone on the AFM is not stuck in the fully depressed state.
satch is offline  
Reply With Quote
Old 09-08-14, 10:52 PM
  #4  
Junior Member
Thread Starter
 
Join Date: Sep 2014
Location: Gillette wy
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
Ok thanks guys. I will give it a shot!
Diamondsnake13 is offline  
Reply With Quote
Old 09-09-14, 11:39 AM
  #5  
Massss BOOOOOST!!
 
FdFrog's Avatar
 
Join Date: Aug 2014
Location: West by God Virginia
Posts: 32
Thanks: 0
Thanked 0 Times in 0 Posts
Definitely sounds like a throttle cable issue..
FdFrog is offline  
Reply With Quote
Old 09-09-14, 07:59 PM
  #6  
Junior Member
Thread Starter
 
Join Date: Sep 2014
Location: Gillette wy
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
What is the vacuum operated part in the picture called?

Sent from my Verizon Wireless 4G LTE smartphone
Attached Thumbnails 89 rx7 goes from start to redline-image.jpg  
Diamondsnake13 is offline  
Reply With Quote
Old 09-09-14, 08:29 PM
  #7  
Moderator
5 Year Member
 
Join Date: Jun 2005
Location: tulsa,ok.
Posts: 11,738
Thanked 2 Times in 2 Posts
You need to be less vague but rather more specific. If you need to rely on a close up pic then have at it.
satch is offline  
Reply With Quote
Old 09-09-14, 08:42 PM
  #8  
Junior Member
Thread Starter
 
Join Date: Sep 2014
Location: Gillette wy
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
The part directly above the radiator cap.
Diamondsnake13 is offline  
Reply With Quote
Old 09-09-14, 08:58 PM
  #9  
Moderator
5 Year Member
 
Join Date: Jun 2005
Location: tulsa,ok.
Posts: 11,738
Thanked 2 Times in 2 Posts
Double Throttle Diaphragm (looks like a small can with a right angled pipe coming from it that connects to a vacuum hose that runs towards the rear of the throttle body and connects to the white plastic nozzle called the thermovalve). Helps keep secondary throttle plates closed when the engine is cold. Could you perhaps provide a close up pic of the throttle linkage at the front of the throttle body? There is a lever in the horizontal position which rests upon the bottom of a short lengthed screw. It is directly in front of the black cap on top of the throttle body. The lever is part of the secondary plates. When idling it needs to be in the same position as it is in your pic. If it, the lever, drops down just a bit from contacting the screw the idle will increase greatly.

Last edited by satch; 09-09-14 at 09:02 PM.
satch is offline  
Reply With Quote
Old 09-09-14, 10:11 PM
  #10  
Junior Member
Thread Starter
 
Join Date: Sep 2014
Location: Gillette wy
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
The picture above is not actually of my car. i removed that piece from my car because it was faulty and somehow misplaced it. i havent been able to find a replacement for it. here is what my car looks like.
Attached Thumbnails 89 rx7 goes from start to redline-10646773_824365000927769_1233941304761323204_n.jpg  
Diamondsnake13 is offline  
Reply With Quote
Old 09-09-14, 10:22 PM
  #11  
Moderator
5 Year Member
 
Join Date: Jun 2005
Location: tulsa,ok.
Posts: 11,738
Thanked 2 Times in 2 Posts
In your pic the lever, which I speak of, is not in the horizontal position which means the secondary plates connected to the lever is causing these plates to be open when you start the car which will definitely cause the idle to zoom to extremely high levels. You need to rectify this issue and the idle will drop substantially.
satch is offline  
Reply With Quote
Old 09-09-14, 10:24 PM
  #12  
Junior Member
Thread Starter
 
Join Date: Sep 2014
Location: Gillette wy
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
thank you very much! from what ive read on here the double throttle system is not exactly necessary for operation. is that accurate?
Diamondsnake13 is offline  
Reply With Quote
Old 09-09-14, 10:32 PM
  #13  
Moderator
5 Year Member
 
Join Date: Jun 2005
Location: tulsa,ok.
Posts: 11,738
Thanked 2 Times in 2 Posts
No it isn't necessary, but even if it doesn't work when in the default position it still keeps the necessary throttle plates closed when idling, which is vitally important.
satch is offline  
Reply With Quote
Old 09-09-14, 10:39 PM
  #14  
Junior Member
Thread Starter
 
Join Date: Sep 2014
Location: Gillette wy
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
Thank you for the info. I'm going to get this puppy running! Correctly that is!
Diamondsnake13 is offline  
Reply With Quote
Old 09-10-14, 09:21 AM
  #15  
Moderator
5 Year Member
 
Join Date: Jun 2005
Location: tulsa,ok.
Posts: 11,738
Thanked 2 Times in 2 Posts
And you need to take care of the vacuum line as well. Normally, there is but one line to the diaphragm but it looks like for yours there are two lines, which likely means the car is/was an automatic as autos have two vacuum lines running to the diaphragm but a standard would only have one (thermovalve has 2 nipples if a standard and three if an auto).

Last edited by satch; 09-10-14 at 09:34 AM.
satch is offline  
Reply With Quote
Old 09-10-14, 09:10 PM
  #16  
Junior Member
Thread Starter
 
Join Date: Sep 2014
Location: Gillette wy
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
My car is a manual, but the motor is a swap from a 91? I think. Very possibly an auto. Should I change that part out or is there anything else I should do?
Diamondsnake13 is offline  
Reply With Quote
Old 09-10-14, 09:25 PM
  #17  
Moderator
5 Year Member
 
Join Date: Jun 2005
Location: tulsa,ok.
Posts: 11,738
Thanked 2 Times in 2 Posts
The white plastic thermovalve is a key tell as to whether it was from a standard or auto. All you need to do is make sure the lever I speak of is horizontal (and from the looks of it that screw is too long and keeps the lever from springing fully closed but it might just be the pic). The first pic provided illustates how it should look. Besides capping the vacuum line(s), you need to make sure you don't get on the throttle immediately after starting a cold engine and prevent from doing so until the engine has warmed sufficiently.
satch is offline  
Reply With Quote
Old 09-10-14, 10:32 PM
  #18  
Junior Member
Thread Starter
 
Join Date: Sep 2014
Location: Gillette wy
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
Ok thank you.
Diamondsnake13 is offline  
Reply With Quote
Old 09-11-14, 07:51 AM
  #19  
Junior Member
Thread Starter
 
Join Date: Sep 2014
Location: Gillette wy
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
Ok i must not be looking at this right.....which lever?
Diamondsnake13 is offline  
Reply With Quote
Old 09-11-14, 09:39 AM
  #20  
Moderator
5 Year Member
 
Join Date: Jun 2005
Location: tulsa,ok.
Posts: 11,738
Thanked 2 Times in 2 Posts
Located at the front connected to the long spring. The lever rests against the bottom of a screw which is mounted through the throttle body.
satch is offline  
Reply With Quote
Old 03-13-18, 01:14 PM
  #21  
Can Post Only in New Member Section
 
Join Date: Mar 2018
Location: Georgia
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
After start goes straight to redline

Hey my name is Luis and I have a 1988 mazda Rx7 and when I start my car it shoots straight to redline
Luisgarcia12 is offline  
Reply With Quote
 
 
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Kyo
2nd Generation Specific (1986-1992)
5
09-16-18 12:32 PM
Th0m4s
Build Threads
24
12-09-17 06:50 PM
86glxNA
New Member RX-7 Technical
7
08-18-15 03:33 PM
86glxNA
New Member RX-7 Technical
3
08-15-15 01:45 PM
Turblown
Single Turbo RX-7's
0
08-14-15 04:48 PM


Thread Tools
Search this Thread
Quick Reply: 89 rx7 goes from start to redline


Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

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.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: