EFI swap question

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It actually depends on the cam you use. If you use a cam with the 351 firing order you would not need to rewire the harness, but you would need to make sure the spark plug wires were routed correctly.


Good luck....
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:nono: DO NOT rewire the harness, just get a new cam. The ECM does not know you switched a cylinder from bank 1 to bank 2, so when the O2 sensors give their readings they will report off (either saying it's too rich or too lean). Thus the ECM will try and compensate for thinking its running rich/lean and your motor will start to run like crud. Something about the ECM's adaptive fuel strategy, and the fact that you would be switching 2 cylinders from each bank (total of 4 that the ECM is expecting to read O2 output from are now not on the correct banks).

Read more here: Ford Fuel Injection Injector Firing Order

Just don't do it, and don't let anyone who hasn't tried it talk you into it. I have tried it - don't do it!

-ended up buying a new harness
-ended up buying the quarterhorse
-shoulda just bought a new cam................


EDIT: I'm looking to get a new cam anyhow as my quarterhorse throws code 15 (as some chips may cause the ECM to throw) you need to ensure you get a 351w cam that matches your setup. IE: I need a 351w hydraulic flat tappet cam in order to get my 1980 block to use the correct firing order since my block cannot take a roller cam.
 
:nono: DO NOT rewire the harness, just get a new cam. The ECM does not know you switched a cylinder from bank 1 to bank 2, so when the O2 sensors give their readings they will report off (either saying it's too rich or too lean). Thus the ECM will try and compensate for thinking its running rich/lean and your motor will start to run like crud. Something about the ECM's adaptive fuel strategy, and the fact that you would be switching 2 cylinders from each bank (total of 4 that the ECM is expecting to read O2 output from are now not on the correct banks).

Read more here: Ford Fuel Injection Injector Firing Order

Just don't do it, and don't let anyone who hasn't tried it talk you into it. I have tried it - don't do it!

-ended up buying a new harness
-ended up buying the quarterhorse
-shoulda just bought a new cam................


EDIT: I'm looking to get a new cam anyhow as my quarterhorse throws code 15 (as some chips may cause the ECM to throw) you need to ensure you get a 351w cam that matches your setup. IE: I need a 351w hydraulic flat tappet cam in order to get my 1980 block to use the correct firing order since my block cannot take a roller cam.

:nice: Good info!!!