V8-Ranger.com

OK,i have a 69 302 with a 351w cam(13726548 firing order)and have the EFI setup of a 86 Lincoln TC 302 NON HO(15426378 firing onder)that i want to install on the 69 engine.Do i have to change the cam back to a 302 one to match the firing order of the 86 computer

I could be wrong so double check my answer but I'm pretty sure you can just rewire the injector harness to the firing order of your cam.

would changing to a HO harness do it

FIRING ORDERS
Another thing to remember when doing an EFI conversion is that there is 2 different firing orders for small block Fords. Early 289's, 302's and some late model 302's run the 15426378 firing order. Late model 302 HO's and 351W run the 13726548 firing order. Installing EFI on the 15426378 firing order is possible, but does not yield the same results as the late model HO firing order. When you mix, match these firing orders you may encounter some driveability problems like poor idle quality. The Mustang EFI system is a sequential fuel injection system, which means that the injectors are fired in a firing order just like the spark plugs. Mixing these firing orders (spark plug & injectors) can cause a rough idle and poor driveability.
If you are building an engine for an EFI conversion, make sure that the cam you install has the 13726548 firing order.
Some people may tell you that all you have to do is rewire the injectors to change their firing order to match your cam or engine. I can tell you from experience that this does not work, it causes erratic fuel control, back firing thru the inatke manifold (at times), rolling or hunting idle and poor driveability overall. I learned the reason for this once I started reprogramming PCM's for different engine modifications. In the Cal Edit Software there is a table called Exhaust Pulse Delay, what this means is that from the time the #1 injector sprays fuel into the #1 cylinder it knows how many crankshaft revolutions it will take before that exhaust (fuel) passes the bank 1 oxygen sensor and so on for every cylinder of that engine.
This also explains why installing long tube headers can cause idle and driveability issue too

I have seen this done with the early model firing order and they ran and idled perfect. It is true that changing just the injector wiring will result in a poor running engine. The fellow that did the set up did rewire the injectors but he also modified the distributor. I am not sure what he did but I will be contacting him tomorrow about helping me set up mine.

i'm on the hunt for a 86 muctang GT computer