The Ford 5.0 Mass-air system

[Grundy]

True, the ford module does need to be cooled, but that can be accomplished with a heat sync off of a computer, or something along those lines. Those ford guys on their forums do that all the time. Well, i'm going to give it a shot and see what happens. It's not that big an investment, and if it works, then all us Mopar guys have a cheap solution to the EFI conversion.

There was additional questions in the previous post on this topic as to firing order and moving around the injectors. It was stated that moving them around to match the firing order would not work. However, my question is this: Did anyone check the cylinder designations between Mopar and Ford blocks? It goes like this:  (bottom of the page is engine front)

Mopar
7-8
5-6
3-4
1-2

Ford
4-8
3-7
2-6
1-5

The mopar firing order: 1-8-4-3-6-5-7-2
The ford firing order: 1-3-7-2-6-5-4-8

The injectors on the ford harness are numbered for the ford cylinder layout.

This is the ford cylinder designations (injector locations),
shown in the chrysler firing order:1-8-6-2-7-3-4-5

SO if you put the ford injectors in this order, it should be sequential and properly ordered. (in thoery)

[57hemicuda]

I had to do that with the System I built too,because the LS1 firing order is different then the Hemi,{the computer doesn't know the difference} It worked fine.

[EFI-Cuda]

Usually, there is more ways than one to resolve a problem.   In this case, the problem is how to get around the differences between the Ford distributor and the Mopar distributor.   I thought about trying to swap out internal components to try to get the Mopar's distributor to work with the Ford computer system, then I came up with an easier solution.   I just used the Mustang's distributor.

I took an EFI Mustang distributor and a non-EFI Mopar distributor to a local machinist and told him to "make it fit".   He was able to do some machining to the Ford's distributor to have it fit into the Mopar's small block.   This is how I got around the distributor issue.   It was not an elaborate or costly solution, and it was a solution that has now worked perfectly for years.

[Future Cuda]

This is the ford cylinder designations (injector locations),
shown in the chrysler firing order:1-8-6-2-7-3-4-5

SO if you put the ford injectors in this order, it should be sequential and properly ordered. (in thoery)

Grundy, maybe I'm not seeing something really plain here, but since all we're trying to do is get the Ford injector control to follow the firing order on the Mopar cam, why is that so difficult? If you simply moved the Ford electronics to our motor with everything in its regular place, you'd end up with the firing order 1-5-6-3-4-2-7-8. Why not move the 5 to the 8, 6 to 4, leave the 3 alone, 4 goes over to 5, 2 lands on 6, 7 stays in place, and the 8 hits the 2 cylinder. The Ford computer will now send injector pulses according to our firing order. That matches the cam, and the plug wires are a no brainer.

I just have this nagging feeling in my head that there are people here that are a lot smarter than me who looked at it this way and said, "That can't work, because..."
Help me understand this! I really want to do this conversion on my Magnum!

[EFI-Cuda]

I just have this nagging feeling in my head that there are people here that are a lot smarter than me who looked at it this way and said, "That can't work, because..."

You are correct.  "That can't work, because..." the computer will not function properly. You cannot simply re-wire the Ford's fuel injector wiring harness to match the Mopar's firing order without causing problems for the computer. I wish it was this simple, but it is not.   

First, I'll try to explain the problem that is created by re-wiring the injectors.  Secondy, I'd like to elaborate on the solutions to this problem.

When the Ford's computer adjusts the pulsing of injectors, it does not adjust each injector's pulse individually. Instead, it adjusts the four injectors on the left bank and the four injectors on the right bank of the engine.  There are two O2 sensors; one in each of the dual exhaust pipes.   These O2 sensors help the computer determine how rich or lean that side of the engine is running.   The computer makes adjustments to the injector firing by adjusting each bank.  Although the injectors are firing sequentially, they are adjusted to run richer or leaner in sets of four (on either the left or right side of the engine).  If you criss-crossed the injector wires form one side of the engine to the other, the computer would be confused when it tries to make adjustments.   Re-wiring the injector harness to match the Mopar's firing order would cause the criss-crossing of the wires from one side of the engine to the next.  And, this would not allow the computer to function properly. 

I worked with a GREAT Ford engineer on resolving the firing order issues. He originally recommended that I do not mess with the Ford's injector firing order. He said that it was fine to let the injectors fire in Ford's firing sequence, just make sure that the ignition firing order followed the Mopar's sequence. He said that this would function similar to batchfire injection and assured me that there would be no difference in idle or performance with the injectors firing out of sequence. Only an emissions sniffer would be able to tell.

Here are the three possible solutions to this issue:
Option #1:  Follow the Ford engineers advice and leave the Ford's injector wiring harness and the injector's firing order alone.

Option #2:  Rewire the firing order without criss-crossing the left bank and the right bank of the engine.  This will result in having 6 out of your 8 cylinders firing sequentially.

Option #3:  Have a chip burned for the Ford computer that tells the computer what is the new firing order.

[Future Cuda]

Here are the three possible solutions to this issue:
Option #1:  Follow the Ford engineers advice and leave the Ford's injector wiring harness and the injector's firing order alone.

Option #2:  Rewire the firing order without criss-crossing the left bank and the right bank of the engine.  This will result in having 6 out of your 8 cylinders firing sequentially.

Option #3:  Have a chip burned for the Ford computer that tells the computer what is the new firing order.

Ah, now it makes sense. When I swapped to euro headers in my M3 I accidentally switched a couple of the O2 sensors which ended up causing the exact same problem, just from a different direction. The computer didn't know why it couldn't control the mixture and ended up burning out the sensors.
Seems like it would be fine to use #1 to get the motor running and drive over to a local shop for option #3. So Grundy's firing order was actually the correct one, right?

[Grundy]

Ahh.. now that sparked the conversation I was looking for.. the additional "hidden" info. So the O2 sensors are tied into the computer.. that makes sense as to why you would have problems.

As for the distributor issue, I'm just trying to look for a way for the average joe to put something together that does not require machining.

[EFI-Cuda]

Seems like it would be fine to use #1 to get the motor running and drive over to a local shop for option #3. So Grundy's firing order was actually the correct one, right?

I've actually used all three options during the time that I fuel injected my Cuda and there is no noticable difference in idle, mileage, acceleration or general drivibility between the three options.  The Ford engineer is probably correct when he says that only an emissions sniffer could tell the difference between the options.   But, since our older Mopars do not have to worry about emissions, any of the three options would be just fine.

[Future Cuda]

As for the distributor issue, I'm just trying to look for a way for the average joe to put something together that does not require machining.

That would be nice. I'm still kind of confounded looking at the differences between the two distributor bodies. I have a 93 Cobra distributor arriving soon and I'm going to drop that and a Magnum 5.9 distributor in my machinist's lap and see what he can do.

[57hemicuda]

I guess that is what makes the coil over plug set up so nice {no distributor  to fight with}But I did change the firing order in the wiring on my GM system,and the first time out went 12.400 @111mph so I know the computer did not know the difference.Is that a bank to bank system or is it sequential?If it is bank to bank,you may be better using a GM TPI system,its bank to bank also but has the same firing order as mopar,and there are HEI distributors avalible for mopars.The sequentials systems are much more accurate though.

[Grancoupe]

Hey grundy? Is the firing order for the chrysler motor correct? From what i can remember number one was on the right. I'm assuming that the front is on the bottom. The ford looks correct to me.

[Grundy]

You know, I think the order is correct, but the odd numbers are on the right and evens on the left. Cylinder one is drivers side front.

check the link i found:

http://www.sevencityracing.com/techarticles/schrys_A.htm

[Grancoupe]

Grundy. That is my point. When you did the conversion from Ford to Chrysler to show the ford cyinder designations with the Chrysler firing order it would make a big difference it the odd numbers are on the left or right. Do you agree?`

[Grundy]

OH boy.. well, the first source I had showed both cylinder numberings with the number one cylinder on the passenger front. But now i see that ford is passenger front and dodge is drivers front. The firing orders that I arranged are now different. You're right there. I'd have to go back and take a look at those orders now to get the right sequence.

[Grancoupe]

No probem. I don't want to beat a dead horse. Looks like no matter what the firing order comes out to be it is still recommended that the injector order is not touched according to EFI-Cuda.