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

How do I know what S4 Engine Wiring harness I need??

Thread Tools
 
Search this Thread
 
Old 06-18-08, 10:29 AM
  #1  
Rotary Enthusiast
Thread Starter
iTrader: (18)
 
Texas_Ace's Avatar
 
Join Date: May 2008
Location: Texas BABY!
Posts: 1,150
Likes: 0
Received 0 Likes on 0 Posts
How do I know what S4 Engine Wiring harness I need??

Ok, well I figured before I spam the BST section some more with questions about this I might as well get the answerers and know what I need first.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>
<o:p></o:p>
So I am picking up an S4 1987 NA Rx7 tomorrow with manual tranny and all stock. The engine wiring harness is bad and possibly the ECU. How do I know which harness I need? I looked in the BST section and I see a lot of different model numbers attached to the harnesses, what do they mean?<o:p></o:p>
<o:p></o:p>
Also, what does the high impedance injectors harness mean?<o:p></o:p>
<o:p></o:p>
Basically what am I looking for??<o:p></o:p>
<o:p></o:p>
Thanks in advance!<o:p></o:p>
Old 06-18-08, 11:03 AM
  #2  
Respecognize!

 
Whizbang's Avatar
 
Join Date: Sep 2004
Location: Anchor Bay, CA
Posts: 4,106
Received 71 Likes on 42 Posts
for that car, if the harness is actually bad (i look into it further), then any harness from 1987.5 to 1988 will work directly. The earlier ones have a resistor pack for the low impedance injectors. ECU wise, the N326 ecu i think was a low impedance driven ecu...can't remember. may not matter.

Basically pre 87.5 had a low impedance fuel injector. The wiring harness was high impedance. They added resistance via the resistor pack to accommodate this. The later models just ditched the resistor pack and used high impedance injectors.
Old 06-18-08, 11:14 AM
  #3  
Rotary Enthusiast
Thread Starter
iTrader: (18)
 
Texas_Ace's Avatar
 
Join Date: May 2008
Location: Texas BABY!
Posts: 1,150
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Low Impedance
for that car, if the harness is actually bad (i look into it further), then any harness from 1987.5 to 1988 will work directly. The earlier ones have a resistor pack for the low impedance injectors. ECU wise, the N326 ecu i think was a low impedance driven ecu...can't remember. may not matter.

Basically pre 87.5 had a low impedance fuel injector. The wiring harness was high impedance. They added resistance via the resistor pack to accommodate this. The later models just ditched the resistor pack and used high impedance injectors.

Thanks for the info! the harness is bad on the car, i could patch it but i would rather get a new one. Rats ate the injectors wiring and when they tried to start it after it it fryed it even more.

So how do i know which injectors i have? It is a 87 that was made in 01-87. Any idea what that would be? or can the harnesses be converted?

Also, what is the differnce in the ECU numbers?
Old 06-18-08, 11:22 AM
  #4  
Respecognize!

 
Whizbang's Avatar
 
Join Date: Sep 2004
Location: Anchor Bay, CA
Posts: 4,106
Received 71 Likes on 42 Posts
that should be pre-1987.5 but just to check, look behind the air box against the headlight. there is a resistor box thing. about 4 inches long maybe 1.5 inches wide. with a larger plug.

I will have to see what the vert parts car i have at my shop is. Either way i probably have everything you'd need.
Old 06-18-08, 11:27 AM
  #5  
Rotary Enthusiast
Thread Starter
iTrader: (18)
 
Texas_Ace's Avatar
 
Join Date: May 2008
Location: Texas BABY!
Posts: 1,150
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Low Impedance
that should be pre-1987.5 but just to check, look behind the air box against the headlight. there is a resistor box thing. about 4 inches long maybe 1.5 inches wide. with a larger plug.

I will have to see what the vert parts car i have at my shop is. Either way i probably have everything you'd need.

I will do that, i am going to get the title later today and then tow it home tomorrow.

I am interested in the harness if you have one, right now i am needing everything cheap, cheap cheap as i am in the process of finishing up a supercharger install on my 4runner.

So bidding starts at free, whos got free harness? No one? dang, worth a try though. lol
Old 06-19-08, 06:02 PM
  #6  
Rotary Enthusiast
Thread Starter
iTrader: (18)
 
Texas_Ace's Avatar
 
Join Date: May 2008
Location: Texas BABY!
Posts: 1,150
Likes: 0
Received 0 Likes on 0 Posts
Ok, i was looking at the car again and trying to see which harness i have. I can't find a box like was decribed. Here are some pictures:








So do i have the later harness?
Old 06-19-08, 06:09 PM
  #7  
HAILERS

 
HAILERS's Avatar
 
Join Date: May 2001
Location: FORT WORTH, TEXAS,USA
Posts: 20,563
Likes: 0
Received 21 Likes on 19 Posts
Your first picture shows the Solenoid Resistor Package. You have low impedence injectors if the car is stock.

If you ever install high impedence injectors, all you have to do is remove that Solenoid Resistor Package and put it on the shelf. Then jumper all five wires in the elect plug that went to it, together.

That thar car done been repainted since it was built.
Old 06-19-08, 06:11 PM
  #8  
Rotary Enthusiast
Thread Starter
iTrader: (18)
 
Texas_Ace's Avatar
 
Join Date: May 2008
Location: Texas BABY!
Posts: 1,150
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by HAILERS
Your first picture shows the Solenoid Resistor Package. You have low impedence injectors if the car is stock.

If you ever install high impedence injectors, all you have to do is remove that Solenoid Resistor Package and put it on the shelf. Then jumper all five wires in the elect plug that went to it, together.

That thar car done been repainted since it was built.

Really? What box is that? the one in the right under the bolt or the one over to the side a little bit? It is all stock as as i know.

Thanks for the info, now just need to get a harness ordered so i can start working on this!

And yes, it was repainted, the color is actually not too bad and the paint job was pretty good to be in this good of shape after a few Texas summers.

I see you are local to me, know of any good places for RX7 parts/cars? check pm's.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
82streetracer
1st Generation Specific (1979-1985)
7
08-23-15 09:28 AM
befarrer
Microtech
3
08-22-15 05:52 PM
Blk 93
3rd Generation Specific (1993-2002)
4
08-19-15 03:47 AM
Professorpeanutrx7
New Member RX-7 Technical
5
08-15-15 01:38 PM



Quick Reply: How do I know what S4 Engine Wiring harness I need??



All times are GMT -5. The time now is 01:24 AM.