Go Back  RX7Club.com - Mazda RX7 Forum > Tech and Performance > Race Car Tech
Reload this Page >

FD ignition problems during righthand turns

Race Car Tech Discuss anything related to road racing and auto X.

FD ignition problems during righthand turns

Old 08-03-05, 12:14 PM
  #1  
Full Member
5 Year Member
Thread Starter
 
Join Date: Oct 2001
Location: Minneapolis, Minnesota
Posts: 146
Likes: 0
Received 0 Likes on 0 Posts
FD ignition problems during righthand turns

I'm posting this here because I have only seen this problem on the track, and I'm hoping another track junkie may recognize these symptoms...

The car is a 1994 stock plus usual reliability mods, ~50k odometer.

On track, during tight mid-speed (30-70mph) right-hand turns, the car severely bogs.

Typically happens after turn-in, when I am rolling the power on.

Power drops off significantly, and RPM (as displayed by the tachometer) drops quickly to 0, and then bounces up and down between 0 & 3000 or so until I straighten out the wheel. From what I can feel, the engine during this time does not appear to be jumping around, it feels like it is smoothly revving down.

The problem appears to get worse as the day goes on and as the car heats up, although that may be unrelated. It does not occur on similar lefthand turns.

Searching has yielded references to rubbing through fenderliners to wires on the other side, and references to bad grounding. I have checked my fender liners, but they appear to be intact (running stock wheels). I have checked engine grounds, also appear to be in good condition.

Seems like it may be some sort of ignition problem, but I don't know where to start looking.

Any ideas of what to investigate? I'm heading to the track tomorrow and then again in about 10 days. Hoping to get some good debugging time in on this...
bros0000 is offline  
Old 08-03-05, 05:23 PM
  #2  
Hobby or mental illness?
10 Year Member
 
RoadRaceJosh's Avatar
 
Join Date: Sep 2004
Location: SW Washington
Posts: 478
Likes: 0
Received 0 Likes on 0 Posts
If your tach is dropping you are loosing the signal to or from the ECU. I would start where the ignition signal is generated at the crank position sensors and move toward the ECU. I'd also check the ECU carefully especially if it has ever been removed.
RoadRaceJosh is offline  
Old 09-13-05, 10:57 AM
  #3  
Full Member
5 Year Member
Thread Starter
 
Join Date: Oct 2001
Location: Minneapolis, Minnesota
Posts: 146
Likes: 0
Received 0 Likes on 0 Posts
In case anyone ever searchs for this problem, the solution in my case was better engine grounding. Likely the engine was losing ground during the turns, and this was causing the ECU to fail (among other things probably) to read the crank angle sensors.
bros0000 is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
C. Ludwig
Single Turbo RX-7's
49
01-30-19 06:31 AM
alphawolff
1st Generation Specific (1979-1985)
17
11-17-15 05:57 PM
befarrer
Microtech
3
08-22-15 05:52 PM
Joe428
1st Generation Specific (1979-1985)
16
08-19-15 06:24 PM
gtcd
1st Generation Specific (1979-1985)
30
08-19-15 02:44 AM


Thread Tools
Search this Thread
Quick Reply: FD ignition problems during righthand turns


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