1G 90 ECU help

[98ls1ttop]

my 90 gst came with an eprom. i bought it with a blown headgasket and we just got it all put back together and the check engine light does not come on with the key and there is no spark, and its just acting like the ecu is dead. i also have a 92 gsx in my back yard with a torched motor. can i pull the ecu out of the 92 gsx and put it in place of the 90 eprom? ive heard that the 90's are for only 90s, but havent heard about the eproms. also, if not, can i rewire it so it will work?

 

[xdxoxuxgx]

Go ahead and try switching the ecu's, they're both 1g turbos so they should work.

 

[92AWDHX40]

Check vfaq for the differneces in ecu i had a 90, but i had to switch some wires around for it to work.
Im not sure about the eproms though.

 

[snowborder714]

Read this post:
http://www.dsmtuners.com/forums/newbie-forum/284285-s-help.html#post151415262

 

[92AWDHX40]

Thanks snowborder for finding that site i could use it myself.

 

[snowborder714]

You're welcome.

 

[98ls1ttop]

ok so i read all of that. what im getting out of it is that you can change pins 6 and 14 and the car will run great, but the tach will do crazy shit. the only way to fix that is either swap the coil packs, and do a bunch of rewiring on the tach behind the gauges. OR you could just order the keydriver chip for 30 bucks. am i right??? swap pins and order keydriver?

 

[snowborder714]

That's what I get out of it. I have not done this though so I'm not 100% positive.

 

[98ls1ttop]

and the "internal tach adapter" looks like a simple diode. something that can probably be bought at radioshack or something. anyone use this? any numbers on the chip?

 

[Asimmons90GSX]

NOOO! It will NOT work. The 90 DSM's are different in several ways besides the ECU. You're going to have to find another 90 ecu or get that one rebuilt.

 

[Asimmons90GSX]

You're gonna waist more time doing all that other crap than it would take you to find another 90 ecu. I'm sure there's one for sale in the classified section of this site. Or go on ebay just make sure it's legit seller with a good feedback.

 

[steve]

my 90 gst came with an eprom.

Post pics of said bad ECU, perhaps it can be repaired.

 

[hedrick]

I had a 90 gsx where the caps leaked causing the car not to start. It happened one day when i was on the freeway and the car just died but about 15 mins it started again and drove for another 20 miles before doing it again. To make a long story short I had an eprom ecu with leaking caps so I bought a 90 non-eprom ecu and it worked just fine. I can tell you that if you watch the boost gauge when you turn the key on and it doesnt move, then its possible you have a bad ecu. Check out the pic of my leaking caps. It didnt take much for the ecu to freak out and stop working.

<a href="http://s155.photobucket.com/albums/s285/hedricm/?action=view&current=thuy037.jpg" target="_blank"><img src="http://i155.photobucket.com/albums/s285/hedricm/thuy037.jpg" border="0" alt="Photobucket"></a>

 

[steve]

I tell people to watch for the CEL turning on for five seconds when you first turn the ignition on and check to make sure the boost gauge goes to 0. If these don't happen then the ECU isn't running and nothing else interesting is going to happen with the car.

The leakage on that ECU is pretty minor in the picture. The other thing that need to be looked at is the three square black chips to make sure they aren't bubbled or cracked. The 68 pin one is the CPU and the two 44 pin ones are the port expander and the interface chip. The port expander is unique to EPROM ECUs.

 

[90gsx16g]

You're gonna waist more time doing all that other crap than it would take you to find another 90 ecu. I'm sure there's one for sale in the classified section of this site. Or go on ebay just make sure it's legit seller with a good feedback.

I agree with ^^^ . Its alot faster to find a 90 ecu and just swap it in. i myself have had 2 bad ecu's and i now have 2 in reserve. one eprom and one not. The non-eproms cost me 50 bucks. Eprom was $200 rebuilt with new caps and warranty. Also you'll save yourself sooo many headaches and frustration by just buying one. Good luck to ya. Just remember that when you buy one the caps arent guaranteed... sucks havin a factory defect like that huh oh well just try to find a rebuilt one.

 

[el guapo]

^^^word

 

[98ls1ttop]

well i dont have any pics of the ecu, my buddy has it right now. ^^el guapo^^ and my buddy put the car together pretty much for me. im currently looking for a new ecu i guess. see what i come across. dsm= wake up and fix it