need help...

I SWAPED A 2.8 FOR A 3.3 FROM A CIERA 1990 TO A 1987 CIERA S/W WITH WIRING HARNESS AND ECU, NOW THE S/W WON'T START NOT EVEN HEADLIGHTS WOULD COME ON , ANY IDEAS OR INFO ABOUT THIS:frown:

Not much info, what works and what does not work in the electrical system, horn radio, ?. Will it crank? Battery up to charge, all the grounds connected? current to the main fuse and distribution center?

SPOKE TODAY TO A COUPLE OF SUPPOSLY 'PROFETIONALS' AND I WAS TOLD THAT THIS CAN NOT BE DONE, BUT THE OLD 2.8 HARNESS THAT CONECTS TO THE FIREWALL HAS 11 PINS AND THE 3.3 HARNESS HAS 15 PINS, SO I WAS THINKING TO FIND A 1990 CIERA WITH THE 3.3 AND CHANGE THE HARNESS INSIDE INCLUDING THE SPEEDO AND EVERY THING THAT COMES FROM A 1990 CIERA I KNOW IT'S A BIG JOB BUT DO YOU THINK THIS MIGHT WORK CAUSE I TRULY WANT TO SHOW THESE GUYS IT COULD WORK, ONE OF THE GUYS TOLD ME THAT IF IT WOULD HAVE BEEN A 3.1 IT WOULD HAVE WORKED. ANY FEEDBACK ON THIS?
CIERA87:mad:

It should at least crank and the headlite come on, isn't that a seperate harness fom the ecu components?

I worked on a durango once where we had changed out a motor, it came off a 4x4, and the one we was working on wasn't. Well, may have been the other way around can't remember for sure. But we kept the harness from the motor we put in it. All the plug connectors matched up. Thing wouldn't run. Then went through everything and realized that even though the plugs matched up that the wire colors on some plugs matched up with wrong colors on the vehicle side. It only wound up being in one place like that under the hood somewhere, I unplugged it. Jumped the right colors to the right colors, and it fired up and ran. Wound up putting the old harness back in after realizing that. The truck had a few problems after that though it because I think some things got shorted out because where it the wrong colors matched up to start with. Go over all of your connectors and look for things like that, like both sides might have a blk/red wire for example, but aren't matching each other when plugged in.