[Gmecm] 749 SCORE sunbird GT 181 merc efi harness--

[David Allen]

I have all the diagrams for this ECM on my tuning laptop. Unfortunately it's 
not here with me (I'm still overseas). The guys at Code59 have the wiring 
diagrams for the Sunbird configuration and the SyTy configuration.

I have always been able to make a good harness by modifying what I have. 
It's very hard to get a custom harness made and shipped in "ready to use." 
They may not be painful, however they also are not always exactly right for 
the application.  It's better to take a used harness and make a custom one 
that is EXACTLY what you need!

Thanks and good luck with your project!
David
  ----- Original Message ----- 
  From: alan mays
  To: David Allen
  Sent: Saturday, September 24, 2011 12:14 PM
  Subject: Re: [Gmecm] 749 SCORE sunbird GT 181 merc efi harness--


                    Hi--Scored one Yesterday, spied a sunbird sold at a 
copart  salvage auction in S texas and tried to find out where it was 
going-first gal wouldn't tell me, Second call I weaseled the info from them, 
had to go to San Antonio and spend 5 hrs in extreme heat but I got it, looks 
like I might have to have a more suitable harness custom made.   I can now 
get one out quicker since I know which leads under the dash are for the ac 
controls.

                     I never did find the aldl port in that car,  I did 
label most stuff under hood that i recognised but it was getting late and I 
didn't want to have to spend motel money and come back the next day   so 
some I didn't spend the time to figure out what they were--o2 sensor was one 
I didnt figure out--and 1 or two under the intake manifold.
                      Im kinda confused why the harness sort of makes a big 
loop and heads back thru the firewall on the driverside????  and it split 
into two parts there--the second side ot that combo plug obviously headed to 
the headlights/headlight door motors.  anyway im thinking it will be 
expensive to have painless make me a new harness but once I got all the 
leads labeled -thats the next step---This car unfortunately was an 
automatic ---There was a lead at the ds--front of the engine,, im now 
thinking that was for VSS and the lead back at the bellhousing was torque 
converter lockup.

                    Glad I finally found one after looking two yrs.


                    Gmecm mailing list
                    Gmecm at diy-efi.org
                    http://lists.diy-efi.org/mailman/listinfo/gmecm



              --- On Thu, 8/25/11, David Allen <davida1 at hiwaay.net> wrote:


                From: David Allen <davida1 at hiwaay.net>
                Subject: Re: [Gmecm] 181 merc efi harness
                To: "alan mays" <truckeez at yahoo.com>, gmecm at diy-efi.org
                Date: Thursday, August 25, 2011, 2:35 PM


                It's super-easy to add in the ALDL port.  Only 2 wires are 
necessary for the computer to communicate.  The serial-data and the ground. 
All the other "fluff" is for factory diagnostics of the remainder of the 
vehicle.

                Just pull out as much length of the ALDL as possible and cut 
it off.

                The fuel pump wiring is routed differently on all the cars. 
It is a very simple circuit so I always just build my own.  You DO NOT NEED 
the oil pressure switch in the fuel pump circuit. I can explain why it is 
there if you care but let it suffice to say you don't need it. The fuel pump 
circuit needs these things: Pump, Relay, Fuse, signal from ECM.  Nothing 
more, nothing less.

                I'm with you 100% on the junkyard stuff.  GM's controllers 
are nearly bulletproof and available everywhere.  Plus there is the stealth 
factor because it is all factory parts.

                Sincerely,
                David
                ----- Original Message ----- From: alan mays
                To: Gmecm at diy-efi.org
                Sent: Thursday, August 25, 2011 2:28 PM
                Subject: [Gmecm] 181 merc efi harness


                Thanks for the input,

                On the GM board there seem to be factions just like the 
bigger efi/diy- when I first signed up there were guys trying to lure me to 
the Megasquirt crowd, but im a junk yard dawg---some are more inclined to 
use the 730 rather Than the 749------Its plain to see why.  i have another 
lead on a turbo bird,  The aldl ports on these are not part of the 
engine/efi harness ---Instead they are part of the dash wiring harness,  how 
do ya'll deal with that-- hours of fun pulling all of it--or is there an 
easier way to add just that part in??

                I know the vss is also part of the dash harness on some but 
remember an attermarket in line add on vss from a speedometer supplier that 
could be used.

                As far as the rear part of the car --the fuel pump in tank 
is the only rear lead to worry about--what section of the harness does that 
tie  into?

                TFtI




                _______________________________________________
                Gmecm mailing list
                Gmecm at diy-efi.org
                http://lists.diy-efi.org/mailman/listinfo/gmecm