I have a 65 289 Mustang vert. I just finished up headers and put the plus wires back in and it runs like crap on maybe 4 cyl. I remember when i took the wires off they didnt seem to be in the correct order but failed to mark them, thinking "ill fix em the right way." Well i put them in as the book says and the car runs like poop. Any ideas why it would run better with the plus wires not in the factory order??? Help!!

 

A different than stock cam can change the firing order.. do U know what cam is in the engine?

Stock, a 289 firing order is 1-5-4-2-6-3-7-8 I believe

Does it backfire now? Did you record the plug order the wires were set at?

 

well now the car idles ok but still isnt on all 8. It fired up with the 351 firing order. The timing was well past 12 degrees and won't run well at normal settings. Any ideas? Maybe the 351 order on the distributor isnt exactly correct?

 

I am not sure about the cam spec only that it isnt stock. The guy who put it in dosent know either. Its supposed to be a fresh motor with only a few thou on it, and I know the guy so he isnt bsing me.

 

Ive never heard of a cam changing the firing order Who told you that???

 

==> Read & learn <==

 

Quote from that site:Unfortunately, this trick won’t work with sequential EFI engines like the 5.0 if a 351W cam is installed, so be forewarned. According to Kaufmann, switching the plug wires will make the engine run, but power will be down dramatically. The fix is a new ECM to establish the correct injector firing order.

Thats only for putting a 351 cam in a 5.0 so this is only for that circumstance and is not true for newer engines which I was refering to

So i guess your right on his car but I knew the newer ones werent like that