[theshadow]

Hey guys, I have an '86 5.0L that originally had speed density fuel injection that came out of a '86 Lincoln Town Car. I converted it to mass-air and am using a computer that would run the late model mass-air mustangs. Would these two firing orders be different or the same? Thanks

[Hack]

HO firing order: 1-3-7-2-6-5-4-8

Non-HO firing order: 1–5–4–2–6–3–7-8
Changing plug wires around is not the solution.

You'll need to swap in a cam from an HO model engine. I'm not certain about the different specs (if there were any between Mark VII's and Mustangs), but since you're using a Mustang computer, I'd find a Mustang HO cam. Very readily available on the re-sale market.

[meangreen92]

I think he can just change the injector firing order, and it will work.

[theshadow]

thanks for the info guys. I was having trouble dialing in and my uncle suggested that there might be a difference in firing order and this confirms. He said the same thing, change cams or change injector order.

[systronic]

so wait, is there a difference between the firing order of speed density HO motors and mass air HO motors? or just HO and NON HO.

i have a 1988 5.0 HO motor, but it IS speed density.

[84 predator mus]

HO firing order is always 13726548

Non HO is always 15426378

HO's use 351W firing order, Non HO's use just plain 302 firing order

i'd just get a HO cam and be done with it if it was me, save the hassle on trying to sort it out lol.

[ttop87]

Originally Posted by theshadow

thanks for the info guys. I was having trouble dialing in and my uncle suggested that there might be a difference in firing order and this confirms. He said the same thing, change cams or change injector order.

Changing injector firing order will not work because the ecu reads off the O2 sencors rightside/left side.I tride it.

[STINGREY]

change the cam and put a new one in not a used one.

[FoxChassis]

Originally Posted by systronic

so wait, is there a difference between the firing order of speed density HO motors and mass air HO motors? or just HO and NON HO.

i have a 1988 5.0 HO motor, but it IS speed density.

There are SD H.O. and SD non-H.O., and there are MAF H.O. and MAF non-H.O..

[carlos351]

Guys, this is confusing, i got a A9L mass air supousedly from a Mustang 1991 GT, and a 302 5.0L HO from the junk yard, i know i can check the engine's firing order on the engine, but how in the world am i going to check the firing order on the ECC? are all mustangs HO? therefore

Also, it was said that swapping the inyectors does not work, i wonder if the ECC can be calibrated to overcome that, say what happends when you install equal lenght headers on the 302 5.0EFI? or equal lenght headers can not be intalled on FB?


Early 289 & 302 1-5-4-2-6-3-7-8
302HO & 351w 1-3-7-2-6-5-4-8





so can not we just have swapped inyector and plug wires 5<->3 and 7<->4 and be Ok?


thanks for your help

[FoxChassis]

"A9L" is the "calibration code" and that is for a '89-'92 5.0L/5-speed Mustang.

All '82-'95 5.0L Mustangs (and '82-'86 5.0L Capris) were H.O.

[EagleAutosports]

If the engine is a Mustang engine, it's an H.O. and you use the 1-3-7-2-6-5-4-8 firing order.

[73 wildpony]

swaping injector firing order will will not help if you have bank firing

[89coupe]

Originally Posted by carlos351

so can not we just have swapped inyector and plug wires 5<->3 and 7<->4 and be Ok?


thanks for your help

NO, what will happen is if the ECM senses a lean condition on one bank then it will try to adjust,and add fuel, but some of the injectors are on the wrong bank, this may cause the other bank to run rich.

Firing order 1-3-7-2-6-5-4-8
bank 1-1-2-1-2-2-1-2

Firing Order 1-5-4-2-6-3-7-8
bank 1-2-1-1-2-1-2-2