upgrading ECU August 25, 2007, 04:09:37 AM i was wondering if it's a plug and play kinda thing to swap ECU'sinjectors vam and ECU swap,i wanted to use a wiring harness out of a 85 T-bird in my 89 mustang, with and 88 TC ECU inj and vam, i don't think my re-pin did all that well, so i don't know what'll be easyer, please help !! Nick Quote Selected
upgrading ECU Reply #1 – August 25, 2007, 09:43:44 AM wowas much as i know about the subject you covered, i wouldnt even consider it . Without even checking, i would have no problem saying "NO" its not plug and play. Quote Selected
upgrading ECU Reply #2 – August 25, 2007, 02:08:11 PM so, the suggestion is to maybe, re-re-pin the ECU ?? i had a problem from the get-go with this swap, car never ran right, nor did it ever run clean, gettin a different motor this week, and wanted to fix the runnin issues before i bolt the new motor in there, i can get all of the parts i want off of an 85' TC so i'm takin the wiring harness, motor and tranny, ECU, and that should be it, But i don't like the way my car ran with the LA3 ECU & big vam, cause something i did went ka-fooey, and one have any links to the re-pin for an 88 TC to 89 mustang ? I thought it was the VAM, cause the CEL light was on, and i ran the codes, and it said something about the wire in the meter. so i bought a new meter, and nothing changed, i un-pluged the VAM, and nothing changed, so it's not even reading the meter at all, i'd just assume get a pinout reading for the TC ecu, and re-pin my entire ECU, i only rember doing about 5 wires, plus " splicing " a wire to the ref. wire. any thing i'm missing here ?? why does this car run like ? PLZ help me !! Nick Quote Selected
upgrading ECU Reply #3 – August 25, 2007, 02:48:54 PM Well any number of things could be wrong....and your posts are too hard to follow to even begin to offer help.Hit up turboford.net and start searching.... Quote Selected
upgrading ECU Reply #4 – August 25, 2007, 07:57:30 PM sorry for my post being hard to read, i'm tired, and frustrated at all the problems i have been having.The start, 89 mustang 2.3 no-turbo (N/A) Turbo swap, with LA3 ECU, brown top injectors and BIG VANE meter.The wiring i did was some instructions printed from some un-known site,Today, Re-read the directions, and found that i had misplaced a wire, the Premuim fuel switch wire, i spliced the Green wire from the ECU to the black wire or VREF wire from the ECU, I disconected that green wire, and started it up, thing ran okay, but not perfect, but the CEL light went out, I'm assuming the bad motor and a bad tune up cause the poor running.i need to know the proper wiring for the premuium fuel switch, or a link to a nice write up that some one else has followed,Thanks Nick Quote Selected
upgrading ECU Reply #5 – August 25, 2007, 08:27:24 PM The premium switch is a negligible issue. It will make no difference in how the car idles. The only thing you need to do is ground the Prem switch wire (pin24) to the SIG RTN (pin46) and it's done.You mention splicing the premium switch wire into the VREF (pin26) that is wrong. Quote Selected
upgrading ECU Reply #6 – August 25, 2007, 10:32:50 PM the instructions i got said " locate the Green w/purple stripe wire This is the AC idle adjustment wire which is triggered off the AC system. Cut the wire from the plug about 5 inches up. cap end of the wire left in the harness as to not short anything the signal for this wires comes from the AC not the computer" That 5" wire, i connected to Pin 46 " sig rtn " (i didn't mean VREF) that wire comming off of the ECU, was connected, and made the car run like . when i dissconected it, the CEL light went away. It's a mystery to me. Quote Selected
upgrading ECU Reply #7 – August 26, 2007, 10:06:15 AM Well that wire is not the Premium switch wire....all that is is the input to the ECU that the AC is on, thus bumping the idle a touch. Quote Selected
upgrading ECU Reply #8 – August 26, 2007, 02:13:36 PM so why would that wire be setting a CEL ? i dunno, i'm just gonna leave it dissconnected, when i get the new motor in, i'll re-scan for codes, how do you do the self test ? i had a scaner at my disposal last time, now i don't ! Quote Selected
upgrading ECU Reply #9 – August 26, 2007, 02:47:47 PM It was probably setting the CEL because it was supposed to be to ground and you supplied voltage to it.... Quote Selected
upgrading ECU Reply #10 – August 28, 2007, 12:16:58 AM according to the diagram i have, ( wiring diagram for an 88 TC ) The wire " pin 24 " goes to the starter relay, AND the premium fuel switch, witch thus would connect to " pin 46 " SIG RTN,that's exactly how i had it setup, i wonder if i got a bad ECU ?! Nick Quote Selected
upgrading ECU Reply #11 – August 28, 2007, 01:28:17 AM PSSST http://www.flemworld.com/click on slug stang, and click how-to's That's the old link i used for my swap ! kinda written werid, that's why i'm soo confused Quote Selected
upgrading ECU Reply #12 – August 29, 2007, 12:47:24 AM i still say your crossing a fine line blending those years 85harness to an 89 stang w/88 tc ecu.ill help you out with the 87 evtm for the 2.3, maybe that will do the trick. Quote Selected
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