gt40 motor and mark VII ecu problems

[mcninetyone]

You do know that the explorers have a different cam, injectors and firing order that REQUIRE you to install a HO 5.o computer from a HO mustang or Mark VII.

Yeah,I do know I need an 5.0 H.O. computer from a Mustang, but I've been told a Mark VII unit won't work. But is a computer swap all thats needed or will I still have these problems after the swap? And I've been told that in swapping the computer I'll also have to move several of the pins around ( but which pins?).

In fact I've been told a lot of things, here are just a few:

The Crown Vic is bank fired, the Crown Vic is not bank fired.

The Explorer does not have an H.O. firing order.

The Explorer does have an H.O. firing order.

You need all the wiring and computer from the Explorer.

You can only use Mustang computers and wiring, nothing else will work.

You must convert to mass air

You don't really need mass air

The cruise will no longer work.

The cruise will work, but the horn won't.

I've heard all this and a lot more! I do know the Explorer has a 65MM TB, #19 injectors and these were used.

Like I said, if this car will run without a mass air conversion and only with a
computer swap, how?

Thanks,

[Lincolnmania]

you need a computer from a 88-92 lincoln mark VII
yes they have integral cruise control.......the mustang ecm's do not

[mcninetyone]

you need a computer from a 88-92 lincoln mark VII
yes they have integral cruise control.......the mustang ecm's do not

GREAT!! A computer from an 88-92 Mark VII, I can do that tomorrow!!

No pin swapping? no extra wires left over?

I assume the Mark VII ecm is an H.O. speed density unit, SO this is just a

plug in and go? Nothing else to plug, unplug or rewire?

No mass air, No surprises?

[Lincolnmania]

yes it's plug and pray

[mcninetyone]

yes it's plug and pray

Plug and PRAY??

I am certainly willing to try it and see what happens.

If I can avoid the mass air conversion it will be well worth it.

Thanks,

[Pirate]

Plug and PRAY??

Yep, plug and pray.

[jayh]

lol

you need an HO pcm. you dont need maf. make sure there is a good vacuum signal- no leaks

[mcninetyone]

Thanks to everyone for the info, I should have a Mark VII computer installed by Sunday, and I'll "pray" this will solve this Crown's problems.

I'm wondering if the water cooled oil cooler from the Explorer will work on the Crown? I know it will bolt up but I wonder if it will clear everything it needs to clear?

And if doing this is even worth it?

Does anyone have any experience with this?

[Lincolnmania]

Thanks to everyone for the info, I should have a Mark VII computer installed by Sunday, and I'll "pray" this will solve this Crown's problems.

I'm wondering if the water cooled oil cooler from the Explorer will work on the Crown? I know it will bolt up but I wonder if it will clear everything it needs to clear?

And if doing this is even worth it?

Does anyone have any experience with this?

no the oil cooler wont clear the steering gear

[pantera77]

Food for thought: It turns out my wagon had an auto stang computer in it. After swapping it to my D9S mark VII comp it's a lot happier. Still has an off idle hesitation, but that could be anything. No more backfiring out the intake, or stumbling at cruising speeds. I'd even be willing to say it has hint more power all around.

[gadget73]

Food for thought: It turns out my wagon had an auto stang computer in it. After swapping it to my D9S mark VII comp it's a lot happier. Still has an off idle hesitation, but that could be anything. No more backfiring out the intake, or stumbling at cruising speeds. I'd even be willing to say it has hint more power all around.

check it for codes. If it comes up with a VSS code, thats your problem. 87- vehicles don't have VSS wiring, and the Mark VII ECM uses vss to do something with the egr. Without vss, it pops the egr valve open right off idle, causing a hesitation.

[87gtVIC]

check it for codes. If it comes up with a VSS code, thats your problem. 87- vehicles don't have VSS wiring, and the Mark VII ECM uses vss to do something with the egr. Without vss, it pops the egr valve open right off idle, causing a hesitation.

And the fix?

[jayh]

And the fix?

delete the egr(just plug the vacuum source)

[jayh]

Food for thought: It turns out my wagon had an auto stang computer in it. After swapping it to my D9S mark VII comp it's a lot happier. Still has an off idle hesitation, but that could be anything. No more backfiring out the intake, or stumbling at cruising speeds. I'd even be willing to say it has hint more power all around.

arent these pcms pinned differently?
some recent threads on another board said mustang and t-bird were pinned differently

[gadget73]

And the fix?

Add the VSS wiring. You could also delete the EGR, but I like the tiny bit of fuel economy it offers.


I wouldn't think that the Mustang auto and Mark VII ECM are substantially different. I know the manual Mustang ones have less initial timing than the auto but that should be it. I could imagine some timing and fuel curve differences but it shouldn't be anything major. The 94-95 Mustang and I think its 92+ Tbird have vastly different wiring, but those are both mass air ecms that you wouldn't be using with speed density anyway.