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Giro
08-25-2014, 03:40 PM
I got a 1990 crate motor to drop into my 1991 sc, and I was comparing the old and new engines, and I found a little difference in the wiring. The old one has what looks to be a temperature sensor on the hose going to the heat core and a respective wire. The new engine comes with the hose, but no sensor or wire on the harness. How important is this, and what are my options

S_Mazza
08-25-2014, 04:56 PM
It's a temperature sensor for automatic climate control. If you don't have that, then you don't need it. If you have that and want to keep it, then you need to transfer over that hose.

Giro
08-25-2014, 09:10 PM
Ok, good to know, thanks. Ill just leave the new motor without, I can live without the auto climate control, plus id probably have to swap the entire harness too just to get that wire hooked up.

Another question, I currently have an SCT chip in the car, that was tuned for 5% pulley, bigger injectors, and bigger throttle body. The new motor is completely stock, can I just pull out the chip and run the motor on a stick computer tune? Or its there a special process that I would need to do to remove the chip?

S_Mazza
08-25-2014, 11:44 PM
Ok, good to know, thanks. Ill just leave the new motor without, I can live without the auto climate control, plus id probably have to swap the entire harness too just to get that wire hooked up.

Another question, I currently have an SCT chip in the car, that was tuned for 5% pulley, bigger injectors, and bigger throttle body. The new motor is completely stock, can I just pull out the chip and run the motor on a stick computer tune? Or its there a special process that I would need to do to remove the chip?

You should be able to pull the chip out and go right back to stock. Of course, it would be a good idea to disconnect the battery first.

Giro
08-26-2014, 12:41 AM
Good to know, thank. Battery has been disconnected for about 6 months now, so that works out.
By the way, anybody know where I can find a knock sensor? Mine broke when pulling the old engine, and I cannot find one anywhere.

XR7 Dave
08-26-2014, 07:02 AM
You have to use the wire harness that matches the car. Do not use a 91 engine harness in a 1990 car. Also make sure you use the '90 02 sensors.

Giro
08-27-2014, 10:05 AM
I guess by that same logic, I can't use the 90 harness in my 91. I am confused about the O2 sensors. The car is a 91, and the engine is a 90. Should I use the o2 sensors to match the car and computer, or match the engine?

gr8ghost
08-30-2014, 12:54 PM
Match the O2 sensor to the car. I don't know exactly what year they went to a 4 wire O2 sensor. the 90 Has a 3 wire. I put some of those in a 95 thinking they'd be the same. '95 needs a 4 wire sensor. Do ya think that made it run funny and throw codes? Ya betcha.