The non HOs use the old 302 firing order, the HO uses the 351W firing order, so if your converting to MAF with a HO computer then your injector firing order is going to be off.
Understood, but I've seen lots of people talk about switching the injector pins at the computer to correct for this. Makes a whole lot more sense to me than swapping cams.
71 Vert,
It seems like you're doing your homework. But why are you switching to MAF? The main reason people switch to MAF is because the system is somewhat more mod friendly. Are you modding the standard 5.0 and keeping the cam.
I'm not switching from SD to MAF. I'm switching to efi on my original 302 engine from scratch. I thought after going to all this trouble I might as well have something that will accept a few upgrades down the road.
I put an edelbrock performer cam along with a matching intake and carb in it when I rebuilt the engine a couple of years ago. I suppose an SD system would probably handle it fine but while I'm doing it I might as well do it right.
Go with the mass air as it is a much better setup and will have the headroom for you to grow with in case new heads are installed down the road. Since MAF has a BAP (barometric absolute pressure) sensor it adapts to changes in altitude and weather conditions so your car is more consistent and it will yield a little better gas mileage from my experiences.
Understood, but I've seen lots of people talk about switching the injector pins at the computer to correct for this. Makes a whole lot more sense to me than swapping cams.
There are 4 cylinders that will fire there injectors and they will be on the opposite bank that they should be. What happens if the passenger side 02 sensors detects a lean condition and ads fuel to compensate but now some of your swapped injectors are on the driver side?
If your going to do it, you might as well do it right you said. Which you either have to swap the cam or buy a Tweecer and change the firing order inside the computer.
But doesn't the MAF system fire injectors to one cylinder at a time (because it's a sequential fire electronic fuel injection, or SEFI) instead of a complete bank at once like the SD. The Ford Fuel Injection site says...
"Firing order does not effect spark at the plugs because that is still determined by what order you put the plug wires on the distributor cap. But if you have a sequential fire fuel injection computer, then the computer opens the injectors in the same order as the camshaft timing. This can be a problem when running a "High-Output" firing order on an older camshaft firing order, or vise versa. Some run a engine with the opposite firing order computer, and it works, with only low idle quality effected. Once the engine speed picks up the injector firing order mismatch will smooth out. Other people with mismatched computers swap pins at the computer plug. This corrects the funny idle and it runs like a dream."