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Discussion Starter #1
My 94 mercury Cougar was running fine half the day than I parked it and came back out to start it to leave and it had a rough shake and smoke coming out the tailpipes smells like gas changed spark plugs, wires, PCV valve, and 02 sensors but still doing the same thing I’m thinking it’s the ECU because I see people saying that a 94/95 have ones that go bad.
 

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1997 Thunderbird 4.6, 1998 Mark VIII LSC
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That was my first thought based on your description - sounds like it's a hanging injector. You can try sequentially disconnecting the injectors (one at a time) to see if disabling one in particular causes it to run better. If so that'll more or less confirm the problem. You can do something similar if you have a noid light - there should be a pulsing at idle. If it's just staying on......
 

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If it ran with the old ECM, and doesn't run with the new one, then you did something wrong. First I would double-check that it is the correct ECM. If it is different, get the right one. If everything is the same, plug the old one back in to see if it will start back up. If it does, then the replacement ECM may be bad. If it still doesn't start, check the fuses; you might have accidentally shorted something to ground in the process of changing it and blown a fuse. If all that is good, then start looking over all the electrical connections that you touched to see if anything is not quite connected all the way.
 

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Discussion Starter #5
Well the ECU should be good got it from autozone for like 200$ car runs for a little bit then just shuts down only thing I touched was the ECU.

If it ran with the old ECM, and doesn't run with the new one, then you did something wrong. First I would double-check that it is the correct ECM. If it is different, get the right one. If everything is the same, plug the old one back in to see if it will start back up. If it does, then the replacement ECM may be bad. If it still doesn't start, check the fuses; you might have accidentally shorted something to ground in the process of changing it and blown a fuse. If all that is good, then start looking over all the electrical connections that you touched to see if anything is not quite connected all the way.
How would I do the relearning process
 

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And it fit and ran?

I for one am amazed.
 

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1997 Thunderbird 4.6, 1998 Mark VIII LSC
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Ebay, junkyard (gamble), a working car being parted out, or these guys.
 
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