91-94 ECU in a 90?

[1stGENracer]

Now I know it doesn't work, but what I've been readin on the forums is that people have been putting 90 ECU's in 91-94's, they just have to change 2 wires. So why wouldn't this work the other way, as to put a 91-94 ecu in a 90?

 

[psychlow]

http://www.ecanfix.com/users/mdhamilton/ecuconversion.html

 

[1stGENracer]

I'm guessing that if this isn't hooked up my car won'ty get spark huh?

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I have this on my car, it says its a noise filter, and when I went to hook this thing up I couldn't find the plug in for it. Crap, hopefully thats all my problem is, then I wouldn't have to buy anything.

 

[smokey90gsx]

What is the benefit of one versus the other?

 

[1stGENracer]

What is the benefit of one versus the other?

Well I can't find a 90 Eprom ECU anywhere, and I can find 91-94 Eprom ECU's pretty easily.

 

[ITSME4G63]

I accidentally bought a 90 ecu eprom (socketed) yesterday, we didn't know that they wouldn't work in 1991-1994 cars, I mean per se, it did work but check engine light came on and it ran like crap. I know you have to switch wire 6 and 14 in order to use a 1991-1994 ecu on a 1990 but I wonder if its vise versa?

 

[psychlow]

Yes you have to swap wires from one to the other or vice versa.

91-94 ECUs have fuel trims that range 100 +- 40%
90 ECUs have fuel trims that only range 100 +- 20%

Also, I believe that the 90's have less agressive timing and fuel curves, but don't quote me on that.

 

[1stGENracer]

I accidentally bought a 90 ecu eprom (socketed) yesterday, we didn't know that they wouldn't work in 1991-1994 cars, I mean per se, it did work but check engine light came on and it ran like crap. I know you have to switch wire 6 and 14 in order to use a 1991-1994 ecu on a 1990 but I wonder if its vise versa?

Would you like to get rid of that 90 ECU? I know someone who would like it.

 

[ITSME4G63]

Yes you have to swap wires from one to the other or vice versa.

91-94 ECUs have fuel trims that range 100 +- 40%
90 ECUs have fuel trims that only range 100 +- 20%

Also, I believe that the 90's have less agressive timing and fuel curves, but don't quote me on that.

can a wiseman confirm this?

 

[ihsviks]

What about a 92 5spd fwd ecu working in an 90 5spd awd car. would this present problems?

 

[1stGENracer]

What about a 92 5spd fwd ecu working in an 90 5spd awd car. would this present problems?

yes it would, I just looked at all the stuff thats needed.

 

[ZyklonBZombie]

not trying to revive the dead but that is the 90 tach sensor ... if you don't run that your tach won't work ...

I'm guessing that if this isn't hooked up my car won'ty get spark huh?

You must be logged in to view this image or video.

I have this on my car, it says its a noise filter, and when I went to hook this thing up I couldn't find the plug in for it. Crap, hopefully thats all my problem is, then I wouldn't have to buy anything.