I did a 5.4 to 4.6 swap would I have too change the computer also?

Tiny
DAMIEN12
  • 2000 FORD EXPEDITION
  • 120,000 MILES

The engine came out of a 99 grand marquis

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Tuesday, July 17th, 2012 AT 12:25 AM

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Tiny
ASEMASTER6371
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The computer is set to the 5.4. Not much difference except some fuel control issues. I would try it to see how it runs before getting a new computer.

Roy

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Tuesday, July 17th, 2012 AT 12:41 AM
Tiny
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I already place the engine in and its runs good but it has a stall to it and it smokes real bad and I was wondering would that computer make it smoke

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Tuesday, July 17th, 2012 AT 3:28 AM
Tiny
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If it is giving a rich command, yes. The 5.4 requires different fuel settings and that may be making it run rich or it may be an issue from the other motor as well.

Get a shop to monitor the computer trims and tell you what is happening

Roy

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Tuesday, July 17th, 2012 AT 1:20 PM
Tiny
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Can I use the computer out of the car that the motor came out of instead of going thru trying too drive it too a shop

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Tuesday, July 17th, 2012 AT 3:33 PM
Tiny
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No, the vin is burned into the computer and if you use that one, it most likely will not run from a vin mis match. You may be able to have the current one flashed by the dealer. Call a dealer service department and see what they say

Roy

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Tuesday, July 17th, 2012 AT 3:35 PM
Tiny
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I spoke with a mechanic at the ford dealership and he said he couldnt flash the computer over to a 4.6, he told me too just get a 4.6 computer to put in there, how do that sound?

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Tuesday, July 17th, 2012 AT 3:46 PM
Tiny
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Not right if he means a used one. The computers are the same, they just need different information

Roy

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Tuesday, July 17th, 2012 AT 4:49 PM
Tiny
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Well I did get a 4.6 computer and the truck started up and shut off and when I try too start it up it wont stay running

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Tuesday, July 17th, 2012 AT 10:33 PM
Tiny
DAMIEN12
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I have installed a computer and a mustang before and it done the samething and when I went back too it the next day it ran perfect do you think I need too give it time to reprogram?

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Tuesday, July 17th, 2012 AT 10:36 PM
Tiny
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It does not reprogram itself. They have to be flashed.

It sounds like a security issue. Did yours or the donor have a security light?

Roy

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Wednesday, July 18th, 2012 AT 3:43 PM

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