87 to 89 engine harness swap

ronniek

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Hey Guys,
I have decided to do a 87 to 89 engine harness swap for a 7mgte ,Is there any differences in wiring apart of ecu connectors.
Ronnie
 

ForcedTorque

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What is your reason for this swap?

You may have problems at the igniter. I know there are a couple different ones, but not sure when the change was. And you could have other plugs at the ECU that don't match the 87 dash harness.
 

ronniek

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I have intermittent problems with throttle sensor and cps.
IWhat is the white connector and the 3 pin connector beside the white connector for.I have noticed the wiring setup on the 87 harness different from 89 harness.
Please see photo ,these are connectors that sit around the ECU area.
Ronnie

ForcedTorque said:
What is your reason for this swap?

You may have problems at the igniter. I know there are a couple different ones, but not sure when the change was. And you could have other plugs at the ECU that don't match the 87 dash harness.
 

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MKIIINA

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its a nightmare. youd be alot better off getting a pre89 harness. the ecu plugs are different, you arent going to have connectors for the HAC and then theres some other issues. the dash as you already found out that its not compatible.
 

ronniek

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I will remove individual wires for my cps and throttle sensor off the 1989 harness to replace the wires in the 87 harness.That way, the connectors will be the same
Ronnie

MKIIINA said:
its a nightmare. youd be alot better off getting a pre89 harness. the ecu plugs are different, you arent going to have connectors for the HAC and then theres some other issues. the dash as you already found out that its not compatible.
 

Jason T

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ronniek said:
I will remove individual wires for my cps and throttle sensor off the 1989 harness to replace the wires in the 87 harness.That way, the connectors will be the same
Ronnie
Before you start that nightmare arange with me a time to have a look at how i have done this take a few minutes remove glove box and have a look


I have done this swap from yellow plug 88 external hac sensor to latter grey plug ecu loom was plug in play all but temp and cold start sensors & rewire main power feed plug to ecu loom was very easy this is the only bit i needed to modify

http://www.supramania.com/photobucket/post-607782-1-YellowtoGreyC1Plug.jpg

Extra wire is the secound air con temp I dismantled a complete engine bay loom in doing this to find no need for secound air con relay both high temp fans work fine with air con this was the only bug i found

The links on SCONZ are what I used to do mine



[its a nightmare. youd be alot better off getting a pre89 harness. the ecu plugs are different, you arent going to have connectors for the HAC and then theres some other issues. the dash as you already found out that its not compatible.
Latter JDM ecu has inbuilt HAC sensor = no problem

You may have problems at the igniter. I know there are a couple different ones, but not sure when the change was.
Same ignitor early and late = Not correct

This site was what I used a info page http://www.supras.nl/index.php?option=com_content&task=view&id=34&Itemid=50
 

MKIIINA

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how can he compensate for the external HAC on the pre89 when the post89 had an internal one?
 

Jason T

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MKIIINA said:
how can he compensate for the external HAC on the pre89 when the post89 had an internal one?

Changing loom to engine to late grey plug ecu deletes external HAC as 89+ has it built into ecu this is one of the many improvments
 

drjonez

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if you have an '87 chassis, the trick would be to find an early '89 engine wiring harness as it should have the same body plugs on it and the later ECU plugs.
 

MKIIINA

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Jason T said:
Changing loom to engine to late grey plug ecu deletes external HAC as 89+ has it built into ecu this is one of the many improvments
yes i know we established that. is he going to be looking for an 89_ ecu then for the HAC input or what? theres a flaw in your system
 

JZ_killa_t68

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drjonez said:
if you have an '87 chassis, the trick would be to find an early '89 engine wiring harness as it should have the same body plugs on it and the later ECU plugs.
:werd:
 

Jason T

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drjonez said:
if you have an '87 chassis, the trick would be to find an early '89 engine wiring harness as it should have the same body plugs on it and the later ECU plugs.
Yep thats exactly what I did

This was plug n play apart from the power feed next to fuse box (same loom type Ronnie now has)

No more external HAC sensor & no need to compensate for it

I went from auto yellow plug to manuel grey plug to use a mines ecu since sold

But tracing wires to fix his problem sounds like a plan
 

ronniek

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I already have 89 ecu,so it should be a straight forward.I need to fix my intermittent problems before I get the maft pro.