Modified Wiring Harness

jeffball610 · Post by **jeffball610** » Mon Jun 28, 2010 9:31 pm

So I've been trying to get this done for quite some time. I think I'm still confused on a couple things, but right now my brain is fried. Can someone check this to make sure it's right? I can make changes as needed.

This is set up for my 1990 ECU. 1991+ will just need to swap #6 and #14.

jeffball610 · Post by **jeffball610** » Wed Jun 30, 2010 10:01 pm

Really? No one has any input? Does this at least look right? I completely eliminated the ISC wiring and have consolidated quite a bit of wiring. I just would like some second opinions before I plug this into my ECU and see if it works.

4g63mightymax · Post by **4g63mightymax** » Thu Jul 01, 2010 5:57 pm

Hi Jeff,

1) Your BW that goes to your ignition coil , MPI relay, etc. needs to be fed power from the ignition switch.

2) Your O2 sensor is missing a couple grounds. I will assume you didn't include them on purpose because they don't connect to the ECU.

3) 5 wires on the CAS seems like 1 Red too many. Are you using a 1G CAS? Or something crazy that I don't understand ?

4) The throttle switch can be tossed and simulated with DSMlink if you are going that route.

5) Make sure your knock and O2 sensors are properly shielded.

6) Pin 108 is hooked up wrong. It needs to be tied into pin 9? (maybe) at the MPI relay / starter switch.

7) Are you going to rewire your fuel pump with 8 awg wire like most dsm'ers do? That may be worth mapping out as well if you feel crazy.

That's all I got for now. I didn't actually match up your pin numbers to see if they are right. The above stuff is off the top of my head. Check it out and let me know if you have any questions.

-Jeremy

jeffball610 · Post by **jeffball610** » Thu Jul 01, 2010 9:08 pm

You found a couple I missed and others have missed. Here is my response from DSMTuners.com.

Yes, there should only be one Red wire on the CAS. However, the ground coming from there is also connected at pins 101 and 106. It's not very clear in my drawing though.

Yes, the BW wire going to the MPI Relay, Coil and Power Transistor should also be connected to switched power at the ignition.

I didn't realize that 63 and 66 were bridged in the ECU. I just followed the stock wiring diagram. I don't see the harm in leaving it this way. Should I change it?

I think I will put a wire in pin 104 for later use in case I decide to go with NLTS. Do I need to ground it now, or is leaving it open the right way to run it?

My only BY wire is going from the MPI Relay to the starter relay. The wire in pin 109 is my tach signal. Labeled as "Ignition Pulse Detect" on the Pinout Diagram I have. Will I need to change this since it's a 90 ECU? I have a 90 Power Transistor laying around I can use. Do I need to run that with my 90 ECU or will this work? Or should I simply swap my 109 into 110?

My only wiring diagram is the crappy Chilton manual and an online Pinout Diagram. I rarely see info on the 1990 stuff, and I know there are a couple of differences in parts. I'll fix this diagram and post another for people to look at.

I just noticed pin 108. I don't think I need that. I should be able to run the ground on 104 since this is a manual car.

I also missed those 2 grounds on the 02 sensor. I have them wired in, but not on my diagram.

Any other info is helpful as I trace down these wires to make sure this thing will work when I test it. (hopefully soon)

Bill Hincher · Post by **Bill Hincher** » Fri Jul 02, 2010 12:15 am

bump

http://projectzerog.com/forum/viewtopic.php?t=1501

slow50 · Post by **slow50** » Sat Oct 16, 2010 2:05 pm

are the diagrams in that link ^ the same for a 90?

Bill Hincher · Post by **Bill Hincher** » Sun Oct 17, 2010 11:40 am

That would be a broad coverage look at Mits wiring design
what is it you are exactly are you looking for?