351W EFI Harness Firing Order with A9L Mustang Computer question

[z70what]

Alright guys (that have done the mustang efi to 351w swap)..

I've got a 74 351w bored .030 with 69 mach 1 heads, trick flow (5.8L) upper and lower intake, 75mm TB, 76 mm MAF, and 24lb inj. I've got a brand new centech harness, and a summit racing 5.0L Engine EFI harness with a mustang A9L computer.

I'm a very mechanically sound person and good mechanical engineer.. however i'm trying to figure out how the mustang computer (A9L) will go from a 302 firing order of 1-5-4-2-6-3-7-8 to a 351W firing order of 1-3-7-2-6-5-4-8. Can i swap the injector wires (2nd fire through 7th fire) on the actual engine and "trick" the computer into firing the right cylinders at the right time? The computer does not take a signal from the distributor and you set up the distributor to fire the correct order with the plug wires and the rotor.. but how do you get the computer to fire the right cylinders without swapping out the injector wires?

Hopefully that makes sense.. it does in my head. Let me know please, i'm getting close to firing up this beast for the first time. Thanks

Luke

 

[COBlu77]

The Mustang HO 5.0 firing order on the A9L will be the same as the 351W. What you do need to consider is that the A9L will not get along well with 24lb injectors, your larger MAF/TB and different heads. Not to mention the increased volume of a 351W and whatever cam. You will need to have the A9L custom tuned to fit all that new stuff the A9L wasn't programmed for. It may run, but not as well as it could.

I'm using a stock A9P, which is very similar, but I've left everything else relatively stock. I've resisted going to all the goodies you mention, because a custom tune is about $500, in my area, and I'm happy with the torque and power as-is.

 

[KyleQ]

I've got a 351W, TFS 185s, 80MM MAF, 70MM TB, 42's and a A9P and I've been told it will run and drive fine, a tune will get me the rest of the power. Only time will tell - but I'm planning on going on Corral and asking a few questions...

 

[Viperwolf1]

Late year 302's (mid 80's and newer) use the 13726548 cam firing order. All 351W motors (with a 351W cam) used the 13726548 firing order. I don't see the slightest problem.

If the 351W has an old 302 cam, 15426378 order, it will still work. The ECM only controls the injector firing order. If it doesn't match the cam firing order 4 of the injectors will fire at a less favorable time. Not a big deal. Think of all the truck motors that fired all 4 injectors on one engine bank at the same time. They still ran fine.