what would cause the motor to not crank after engine swap?


Asked by Mar 30, 2016 at 02:19 PM about the 1999 Mazda Millenia 4 Dr STD Sedan

Question type: Maintenance & Repair

Hey i recently did a engine swap between two identical 99's millenia's with the
2.3 engine and now the new motor wont crank over. I've tested all the relays
and i am stumped at this point. did i do something wrong or did i need to
change the ecu as well? please help i need my wheels back

3 Answers

Tom Demyan

recheck all your connections and grounds. Was the other motor running before the swap?


ya both ran I've checked all connectors and think i have the ground hooked up. do you know of any other grounds besides the one on the rear engine mount? I've leaned towards the trans. range sensor even though i have changed it out of the other car and still nothing has changeed


It's the security system in the Milli. It's no fun to correct. You need to hotwire the car to trick the system. Jump the starter solenoid with a wire to the positive side of the battery with the ignition switch turned on. Do it twice and it should turn over. Then reconnect the starter wire and turn the key. All should be good. Mazda gets 200.00 to reset the ECU.

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