Microtech Area is for discussing Microtech systems

FD LT8s ECU Issue

Old 11-01-15, 08:17 PM
  #1  
Rotary Freak
Thread Starter
iTrader: (30)
 
andre sinclair's Avatar
 
Join Date: Jan 2002
Location: Rx7
Posts: 2,812
Received 0 Likes on 0 Posts
FD LT8s ECU Issue

Hello members,

I purchased a FD LT8s ECU from Centeral Florida Turbo about six years ago. Since I have install the ECU, I've had some concerns regarding the wiring of the crank sensors. The wiring of the crank sensors in the manual show it being wired one way; and the Mircotech website shows the wires in the reverse of what the manual states.

I've spoken to John from Microtech and he advise me of a wiring correction; and that I should follow the wiring diagram on the website.

I have now gone threw my 4th engine, corner seals are always running flat. I know flats corner seals are the result of heat due to timing. I run about 32 degree in vacuum, AFRs being 13.4 a 13-8; 13-15 degree advance at 18 psi, AFRs being at 11.2-11.4

I now need of some advise from a Microtech guru. Should I buy a new ECU (9C, 10C, or LT16C) or go with something else. Or what can I do to correct this issue... Please advise!

thanks


Andre

Last edited by andre sinclair; 11-01-15 at 08:25 PM.
andre sinclair is offline  
Old 11-02-15, 09:16 AM
  #2  
Sharp Claws
iTrader: (30)
 
RotaryEvolution's Avatar
 
Join Date: Oct 2003
Location: Central Florida
Posts: 5,135
Likes: 0
Received 14 Likes on 13 Posts
a new microtech won't fix anything, the new "c" series is the same thing in a shiney new package. you will need to diagnose your issue first, have you verified that your leading and trailing is firing in the correct order and timed correctly?
RotaryEvolution is offline  
Old 11-02-15, 10:24 AM
  #3  
Rotary Freak
Thread Starter
iTrader: (30)
 
andre sinclair's Avatar
 
Join Date: Jan 2002
Location: Rx7
Posts: 2,812
Received 0 Likes on 0 Posts
LT8s

Please take a look at the diagram... Crank sensor are wired in the reverse.

At this point I don`t know which wiring diagram is the correct.
Attached Files
File Type: pdf
LT8_93 rx7.pdf (223.8 KB, 80 views)

Last edited by andre sinclair; 11-02-15 at 11:38 AM.
andre sinclair is offline  
Old 11-02-15, 11:27 PM
  #4  
Sharp Claws
iTrader: (30)
 
RotaryEvolution's Avatar
 
Join Date: Oct 2003
Location: Central Florida
Posts: 5,135
Likes: 0
Received 14 Likes on 13 Posts
car wouldn't run if the CAS wasn't wired correctly.


see, Microtech is funny that way. they have used numerous different harnesses over the years and can't even tell which they used and when, so you have varying wiring diagrams with corrections on them. most any other EMS would reprint the schematics, nope, they felt scribbling ink on theirs was "good enuf" when all it really does is makes people feel uneasy about their wiring job.

Last edited by RotaryEvolution; 11-02-15 at 11:32 PM.
RotaryEvolution is offline  
Old 11-03-15, 08:40 AM
  #5  
Rotary Freak
Thread Starter
iTrader: (30)
 
andre sinclair's Avatar
 
Join Date: Jan 2002
Location: Rx7
Posts: 2,812
Received 0 Likes on 0 Posts
Funny you should say that. Because I've pinned out the wires according to Microtech instruction
and the car starts and runs which seems to have no issues. However, when I revert to rx7 technical manual it states the opposite and the car starts and runs with no issue as well. (Puzzled now to which wiring is the correct way)

See attachment.

I guess I'll have to check and see which wire supplies the ignition power and then wire the crank sensors according to the technical manual.
Attached Thumbnails FD LT8s ECU Issue-image.jpeg  
andre sinclair is offline  
Old 11-03-15, 04:12 PM
  #6  
Sharp Claws
iTrader: (30)
 
RotaryEvolution's Avatar
 
Join Date: Oct 2003
Location: Central Florida
Posts: 5,135
Likes: 0
Received 14 Likes on 13 Posts
there is no ignition power. the sensors are magnetic pulse generators that pulse very small voltage signals to the ECU and the ECU converts them into digital form for trigger inputs. it's been a while since i have wired a microtech but the majority of the issue was between the home and ref signals, not so much the an+ and -.
RotaryEvolution is offline  
Old 11-04-15, 08:01 PM
  #7  
Rotary Freak
Thread Starter
iTrader: (30)
 
andre sinclair's Avatar
 
Join Date: Jan 2002
Location: Rx7
Posts: 2,812
Received 0 Likes on 0 Posts
Spoke with a friend from Speed 1 Rotary and they said they're having the same issue with the old LT8s ECU. Therefore, it seems to be an issue with the ECU's wiring.

Also, if you look on the Microtech EFI website the made a correction to the wiring diagram of the LT10 ECU's crank sensors and ignitor.

Anyone has great success with Megasquirt version 3 on a 13b?
andre sinclair is offline  
Old 11-04-15, 09:49 PM
  #8  
Sharp Claws
iTrader: (30)
 
RotaryEvolution's Avatar
 
Join Date: Oct 2003
Location: Central Florida
Posts: 5,135
Likes: 0
Received 14 Likes on 13 Posts
they have corrections for virtually every series of microtech, however i am not sure that the CAS wiring is really your problem with it.
RotaryEvolution is offline  
Old 11-05-15, 09:07 AM
  #9  
Senior Member
 
Join Date: Nov 2006
Location: connecticut
Posts: 362
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by andre sinclair View Post
Spoke with a friend from Speed 1 Rotary and they said they're having the same issue with the old LT8s ECU. Therefore, it seems to be an issue with the ECU's wiring.

Also, if you look on the Microtech EFI website the made a correction to the wiring diagram of the LT10 ECU's crank sensors and ignitor.

Anyone has great success with Megasquirt version 3 on a 13b?
I have used ms1,ms2 and now a microsquirt on rotaries with out a single problem ms3 should be no problem controlling a Wankel engine
elturbonitroso is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
1st_gen7
1st Generation Specific (1979-1985)
11
10-25-15 08:33 PM
Arcolithe
1st Generation Specific (1979-1985)
14
10-18-15 04:45 AM
bryancmatthews
Power FC Forum
9
10-14-15 01:25 PM


Thread Tools
Search this Thread
Quick Reply: FD LT8s ECU Issue


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: