Hi Stewart, I have just switched motors in my 93 eagle summit with a 96 mirage motor.I have had to change the wiring computer ect,from the replies I have received from you previously.That all worked out for me I have the car running and everything but I've noticed everytime i hit the throttle it wants to cut out on me.I've noticed a sensor under the seat on the 96 mirage that is running down to the exhaust one that my 93 dosen't have.Do you think this could be making it bog down as I accelerate?If not could I get your opinion on what may be causing it to bog?
Your Mirage engine has two O2 sensors, as I recall, one before the cat and one after. This is what the second wire should be connected to. It MIGHT be the cause of the bogging down.
That is, the 2nd O2 circuit is open, and the ECU is getting no signal. What this will do the the ECU operation is unclear: most likely the ECU will revert to basic mode (ie the engine will run, and typically use more fuel ... its equivalent to what happens when the engine is started with a reset ECU). In any case, the ECU should be reporting an error code that the rear O2 sensor is faulty. It may be reporting more errors too. Your 93 harness is OBD-1, the 96 ECU is OBD2, and the diagnostic connectors are different.
Alternatively the engine may be running very lean: a high operating temperature is the common symptom. You should be able to touch a hot intake manifold for about 5 seconds: if its too hot to touch, the engine is running hot.
The Check engine light should be on. If it's not, verify that a) the CEL bulb is functional; and b) your wiring mods are correct and complete. You should have made up a comparison table of the wiring mods needed by comparing the 93 ECU and 96 ECU connection schematics. You would have noticed in doing this that there was a second O2 sensor. I suspect you have something other than the missing O2 sensor wrong or missing.
The rear O2 sensor is quite expensive new, and is AFAIK a 3 wire heated type. You could probably fool the ECU by providing a resistor network and an approx sensor voltage, to check if the bog down is related. You could try to source a rear sensor from a 94-96 4G15 or 4G93 at your local wrecker.
Since the engine will run quite happily (if ineffeciently) in basic mode, I'd first check ECU error codes, look for damaged vacuum hoses, verify the cam belt alignment and timing, and the fuel supply.
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