i just got through doin a 2.3 to 5.0 swap. 5.0 out of 89 and put it into a 90 2.3. i used the motor harness and computer out of the 89. Every thing works but the fuel pump want come on. the realay is good and you can straight wire it and make it come on. i was told i might hafta switch the wiring harness behind the dash of the 89 in to the 90 to get it working. is there any way around this or will i hafta to do it anyway.

 

You could just straight wire it but use a toggle switch to turn the pump on and off so it doesn't draw on your battery when the car is off. Just mount the switch on the dash like in the McLarens.