wiring harness differences between 90-91?

[motoman358]

I hear there are differences in the 1990 and 1991 wiring harnesses, what are the differences between them? I just picked up an engine and ecu and i was told they were from a 91, but i just want to be sure so that i get the right harness; so how can i tell if my engine and ecu are really from a 91?

 

[Julioluko]

As for the wiring harness, im 95% sure its exactly the same, my cars are 3 hours away from me so i cant check, but Im almost positive.

Well as for the engine year, the throttle bodies are diffrent from 90-91, if you have one with 4 vaccum tubes comming off the top you have a 91-92, if you have 2 you have a 90, also the oil pumps are diffrent, of you have an external oil cooler you have a 90. Also i hope you got a 6 bolt, one way to tell is the cam angle sensor on the left side of the engine, if its a black top its 7 bolt 93-94 if its greenish and big its 90-92, the valve covers are different too, but i dont have one of those in front of me. You might be able to get the engine block number, its on the front of the engine just below the turbo on the right, with that you could call the dealer and they might be able to tell you also.

The only thing that i can think that would be diffrent for the harness would be the oil pump, but if that is the case its not hard to wire. rock on

 

[steve]

So how can i tell if my engine and ecu are really from a 91?

Check the ECU part numbers against the VFAQ list or mine to see what year it's from. Sometime people swap stuff around so you can check that the 4 digit number on the white edge connector matches the last 4 digits of the E2T number on the case.

The 91+ engines don't have pigtales on the TPS, CAS, ISC like the '90s do.
A 91+ valve cover has a straight port on the breather where the 90 ones have a 90* elbow.
The 91+ throttle bodys have 4 port on the top where the 90s have two.
'90, 91, and early '92 engines are six bolts rather than the 7 bolt versions used in mid/late '92 on. Check the VFAQ site for identifying the between the two.

Steve

 

[motoman358]

thanks for the help guys. i do know fo sure that it is a 6 bolt, but i am confused because it has 4 vac lines on the tb, but has(had) an external oil cooler. thats where my main point of confusion lies.

 

[mbyoung424]

Bring this back from the dead. I have a 92, 5 speed AWD that I need an engine wire harness for. I found one that's from a 90 and saw that the 91+ don't have pigtails for the TPS, CAS and ISC.

What do you mean by "pigtail?" My 92 has connectors on all those.

 

[19Eclipse90]

On a '90, the CAS and TPS have a bit of wire attached to the sensor itself with a intermediate connector at the end of that wire that connects to the rest of the engine control harness. On a '91+, this was changed and the engine control harness connects directly to the sensors.

You can read about all the differences between the harnesses here: The 1990 Engine Control Wiring Harness

 

[mbyoung424]

Thanks for that link.