Jump to content


Welcome to Ultimate Subaru Message Board, my lurker friend!

Welcome to Ultimate Subaru Message Board, an unparalleled Subaru community full of the greatest Subaru gurus and modders on the planet! We offer technical information and discussion about all things Subaru, the best and most popular all wheel drive vehicles ever created.

We offer all this information for free to everyone, even lurkers like you! All we ask in return is that you sign up and give back some of what you get out - without our awesome registered users none of this would be possible! Plus, you get way more great stuff as a member! Lurk to lose, participate to WIN*!
  • Say hello and join the conversation
  • Subscribe to topics and forums to get automatic updates
  • Get your own profile and make new friends
  • Classifieds with all sorts of Subaru goodies
  • Photo hosting in our gallery
  • Meet other cool people with cool cars
Seriously, what are you waiting for? Make your life more fulfilling and join today! You and your Subaru won't regret it, we guarantee** it.

* The joy of participation and being generally awesome constitutes winning
** Not an actual guarantee, but seriously, you probably won't regret it!

Serving the Subaru Community since May 18th, 1998!

Guest Message by DevFuse
 

Photo
- - - - -

ignition pulse wire for 85-87 mpfi


  • Please log in to reply
10 replies to this topic

#1 archemitis

archemitis

    guy smiley

  • Members
  • 3,554 posts
  • the big minnie

Posted 28 November 2003 - 02:41 PM

i have conflicting info on my wiring diagrams.
my diagram shows a wire from the negative of the coil going to the computer. its supposed to be straight yellow. my engine harness has no yellow wire, just striped ones. also the diagram says it will change to a shielded wire:-\

i need to know what color this wire should be. close to the computer. maybe this is too vague, i just gotta figure where to hookup my ignition pulse. i wuld hate to give power to my ground side of the coil.

#2 MilesFox

MilesFox

    Catch this Fox!

  • Members
  • 10,441 posts
  • Madison/Milwaukee, WI

Posted 28 November 2003 - 03:05 PM

what yearis your schematic for?
the 87 uses the crank angle optical disty, wheras 85-86 uses a mechanical tyoe with stand-alone knock control unit.

the shielded wire has a gray sheath, i think the middle wire id red?

what does the distributor look like?

#3 archemitis

archemitis

    guy smiley

  • Members
  • 3,554 posts
  • the big minnie

Posted 28 November 2003 - 03:10 PM

its an 85 xt motor and harness. the disty has two vac ports. i have a diagram from the net that is for the flapper style. the diagram shows a knock sensor, but i am na, so i dont have one.
i have got power to all the stuff that needs 12 volts, so i think ALL i need now is the correct igniton pulse wire, and its loud time. i only have part of the harness, so i am runing the wires that i dont have.

thanks

i was thinking it had to be that grey one

#4 MilesFox

MilesFox

    Catch this Fox!

  • Members
  • 10,441 posts
  • Madison/Milwaukee, WI

Posted 28 November 2003 - 03:19 PM

yeah, it will have a braided wire like that of coaxial cable.

#5 archemitis

archemitis

    guy smiley

  • Members
  • 3,554 posts
  • the big minnie

Posted 29 November 2003 - 11:31 AM

well, the gray wire, has two wires going into it. im guessing the black one is the shield, and has to be grounded? does this sound right? also, miles, you ever smoke a computer because it was hooked up slightly wrong? because thats my biggest fear here, and why i am trying to get this figured.

#6 MilesFox

MilesFox

    Catch this Fox!

  • Members
  • 10,441 posts
  • Madison/Milwaukee, WI

Posted 29 November 2003 - 12:19 PM

the ecu will have its black wire for ground

the braided portion i think would ground to the distributor or something, but its not the computers ground. its the middle sheathed wire that will be the signal wire.

the ecu i have exp. with was only gutted out. i havent hooked it up, because we couldnt get the flexplate bolts out to swap the motor to a flywheel.

i have fried mt nintendo by jumping the contacts on the cartridge to get the screen to do crazy tricks

i thought i have fried mt computer swapping drives when it os on, but it was an internal breaker in the power module, and everything checked out.

i have a spare ecu for 87 turbo if there is a way to get it to you should you fry yours. keep me up on your progress......

#7 archemitis

archemitis

    guy smiley

  • Members
  • 3,554 posts
  • the big minnie

Posted 29 November 2003 - 12:23 PM

since there is only one signal, these are batch fire injection system right?

#8 MilesFox

MilesFox

    Catch this Fox!

  • Members
  • 10,441 posts
  • Madison/Milwaukee, WI

Posted 29 November 2003 - 03:15 PM

i dont know about batch fire.
if i told you what i THOUGHT i knew, one of our 2 favorite board mermbers would jump my rump roast about it.

i will have to leave that one alone

#9 archemitis

archemitis

    guy smiley

  • Members
  • 3,554 posts
  • the big minnie

Posted 29 November 2003 - 03:41 PM

we'll just keep em out of here then:banana: :banana: :banana: :banana: :banana: :banana:

#10 TomRhere

TomRhere

    Certified BRAT nut!!!

  • Members
  • 3,969 posts
  • Hillsdale, Mi. USA

Posted 29 November 2003 - 09:03 PM

Do believe that the shielded wires in the ECU wire loom, are all ready grounded at one of the grounding wires of the harness. You can check that easily enough with a multi-meter or test light.
As Miles said, the shield is a braid like that of co-axial cable, and is usually just under the outer jacket of the wire/cable.
You only need one end of it grounded. If you ground both ends, you will induce noise into the wire, not eliminate it. You don't want noise in the wire, gives false signals to the ECU.
Been studying the wiring diagram I have for the '88 XT-6. It is different than what you have, as far as the coil wires go, but I don't believe that you want to ground that Black lead that you mention.
But I have been wrong before.

#11 archemitis

archemitis

    guy smiley

  • Members
  • 3,554 posts
  • the big minnie

Posted 30 November 2003 - 10:04 AM

well, heres what i did.
the shield went right into a connector, that i assume had a wire on the other side that went to ground. so i grounded the shield, and then i put the wire inside of that one(turned out to be black), onto the negative side of the coil. so cold my damn soldering gun isng getting hot enough. im gonna go turn it over and see if i can get any signal to the fuel injectors. i do have spark, and fuel pressure!




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users