Can not get it to start. Turns over. Replaced wires, coils, ECM, check fuses and fuel pump is on. Power to coils.
Do you actually have any spark? As in - did you visually check for spark at the end of the plugs? The pump runs, but do you actually have proper fuel pressure at the rail? Is the timing belt intact?
No spark at a plug. Need to re-check fuel rail, thought it had pressure. timing belt ok
Check the cam and crank position sensors and their wiring since it can’t make spark without them. Hopefully you’re doing all of this with a repair manual which will have specs for checking those. If not you may be able to get the specs at Autozone’s website.
You also may want to give folks some more info at this point - year, mileage, history. How did you get to this point? You replaced the ECM but before that did you have any error codes/check engine light?
It is a 2002 with 120,00 miles. Have replaced the crank sensor after testing said it was bad. Still no spark. What would happen if the batt pollarity was reverse for short period?
What would happen if you reversed the polarity of your batt terminals? LOL…BAD BAD BAD things…It could easily FRY your ECU. It is rather difficult to do this so no manufacturer can protect themselves from people who actually wind up doing this. It would be bad and could possibly affect every single electrical component on your vehicle.
I hate to wonder why you just asked this question. Now…almost anything can be at fault.
Please explain your curiosity about battery polarity reversal…this is QUITE IMPORTANT and methinks has MUCHO to do with your no start situation. I am sad to even think about this. Let us know more please.