General 90 ecu...what will work

[Ace_gst]

I have a 1989 eclipse gst and i need a new ecu. Im just wondering what ecu's will work in my car or if only a 89-90's will work. Or should i let it sit for a few months and save for link?

 

[crash89]

I bought a 90 talon not too long ago and was told it had a 91 ecu in it.. My tach doesnt work though. Ive read that its from the difference in the way the ecu reads the tach signal so I much have a different year ecu in the car. Car runs fine, you should be ok with a later model ecu.

 

[Ace_gst]

Hey thanks alot, think i want my tach to work tho. Might send it off to emctuners to have it repaired.

 

[lilsam]

I believe that you can switch around like pins 2 and 14 on the ecu harness plug and it will work?

 

[Ace_gst]

Yea i think for about the price of a new one i can get mine repaired...I don't know electronics very well so im iffy on buying them used.

 

[Bud92gsx]

There are two pins you can switch..I have it all writtin down..But it's in my tool kit..Which is in the back of my girls car..
If you can find an 89-90 ecu just go with that.For ease of installation..

 

[steve]

If you want the tach to work without changes to the wiring you need a 90 ECU. 91+ ECUs will make the car run if you swap pins 6 and 14 but the tach is likely going to malfunction.

If your car started out life as a California car you want a MD128623 (FWD) or MD145902 (AWD) but you can use the Federal ECUs if you don't have to pass smog any more MD128625 or MD145903.

 

[Ace_gst]

Yea i live in California but i have already deleted the egr and charcool can and every thing else that goes to the emissions, plus i dont have a cat. Dont tell them tho

 

[steve]

Then you want a federal ECU so you won't be stuck with a constant CEL

 

[Ace_gst]

Know any one who happens to have a federal ecu from a 90 for sell

 

[anchew02]

hey guys, I have a 90 gst and i switched out the ecm to a 91-94 ecu and it works fine except my tach worked up to about 5500 rpms and then it would drop off. I talked to jeff from dsmchips and tried to get a tach adapter and he told me to cut a wire coming out from the ecu, i believe its pin 110 and my tach works perfect now. im going to double check tonight but it thats all your worried about is the tach problem, just do what i said... on a side note i still have my 90 ecu in perfect condition for sale.