TCCoA Forums banner

1 - 20 of 42 Posts

·
Registered
Joined
·
29 Posts
Discussion Starter #1
Hey guys, iv got a 90-bird that had a 3.8 and I just swapped a 4.6 dohc out of a 94 mk-viii. Iv got the pcm hooked to the motor and power and ground, I'm not getting spark. Iv got acess to the full harness also. Please help.s any input is great. Iv been fooling with this for a few days now and can't seem to figure it out. Thanx in advance!!
 

·
Registered
Joined
·
7,758 Posts
Do you have the EVTM's for both the MN12 and the FN10?
 

·
Newbie
Joined
·
5,650 Posts
Do you have the EVTM's for both the MN12 and the FN10?
X2. You are going to need them for this. There are several power wires and several grounds to the computer, and that's just part of the equation. There's also the VLCM, etc.
 

·
Registered
Joined
·
29 Posts
Discussion Starter #4
Evtm? Vlcm? I have all the components from both cars available. Also I have been looking at the pinout from the 4.6 and have all the power and grounds grounded and powered... lol.
 

·
Registered
Joined
·
7,758 Posts
I am also using my c4 instead of the 4r70w
No you're not, as a C4 will not (easily) bolt to a modular engine.

(Unless you're using something like this: http://www.campbellenterprises.com/parts.php?type=search&query=jwp9246246)

Sorry to be blunt, but if you don't know what an EVTM is, then you should not be attempting this project.

And before you ask what an EVTM is: :gotsearch

Seriously though, I highly recommend you searching on here and on the internet to learn more about what you're attempting.

Your swap is definitely doable, but not all that simple or cheap.

Good luck :thumbsup:
 

·
Registered
Joined
·
4,147 Posts
Yeah .. even if you get the car started it will probably be in Limp mode with the transmission not connected to it.

OKAY .. for the wiring on the Mark .. opening up a can of worms. Did you use the Engine bay wiring harness ?? Or splice the Tbird harness with the Mark one ? There are some wires that go from the driver side to the passenger side VIA the dash if you are using the Mark engine bay harness ... without an EVTM, you're up a creek with no paddle.
 

·
Registered
Joined
·
29 Posts
Discussion Starter #8
I AM using my c4, it IS bolted to my 4.6 and in the car. It said it wasent possible but I did it. And I'm sure I know what it is but I am bad with acronyms. And not to be blunt but if your not gonna help please don't post in this thread.
 

·
Registered
Joined
·
29 Posts
Discussion Starter #9
As of now all I have hooked up is the pcm to the main engine harness. I'm using the start circuit and fuel pump circuit from the bird.
 

·
Registered
Joined
·
29 Posts
Discussion Starter #10
I don't exspect to have the answers handed to me. It seems that everytime someone asks a question on here everyone tells them to "search the site" iv looked here and on modularfords.com for anything that'll help. I can't seem to find anyone that has done this kind of swap. If someone can put some simple instructions in simple termanology it would be greatly appreciated!
 

·
Registered
Joined
·
7,758 Posts
I AM using my c4, it IS bolted to my 4.6 and in the car. It said it wasent possible but I did it. And I'm sure I know what it is but I am bad with acronyms. And not to be blunt but if your not gonna help please don't post in this thread.
Please enlighten us as to how you accomplished this. Did you use/make an adapter?

But to "help”:
Have you ordered the PCM chip/tune to disable all the required inputs from the transmission?
Did you verify that the 94 FN10 PCM directly feeds the fuel pump and does not use a FPCM (the Gen II's use a FPCM)?
Are you getting fuel/prime when you turn on the key?
Does it crank/spin, but just not getting spark.
Are the injectors firing?
Do you have the Electrical and Vacuum Troubleshooting Manual for both cars?

Here's the deal. You have to compare everything between the 3.8L system in the T'bird, and everything the 4.6L needs. And that is impossible without the EVTM's.

Your problem might be something as simple as no "park/neutral" signal from the transmission.

As I said, just the 3.8L to 4.6L swap isn't that simple, but when you add the fact that you're also using the C4, you're just complicating the issue.

But as I said, good luck and don't worry, I won't post anything else. :thumbsup:
 

·
Registered
Joined
·
550 Posts
If you are using the 94 DOHC engine harness and computer Then you must have the short section of harness that connects between the two. This short section also connects to the engine bay harness, the dash harness as well as the EDIS, Electronic Distributorless Ignition System, module. The computer needs signals to/from this module in order to run the car. To run the DOHC, you are going to have to transfer more of the Mark components into the Bird.

Did you verify that the 94 FN10 PCM directly feeds the fuel pump and does not use a FPCM (the Gen II's use a FPCM)?
The 94 used the VRCM mentioned earlier. it pluggs into the engine bay harness and controls the radiator fan and the fuel pump. Not sure if it does anything else.
 

·
Registered
Joined
·
29 Posts
Discussion Starter #13
Thank you for the input daily 4.6, sorry I snapped a little iv just got a lot on my plate and this project is one of them... lol. There is a little chunck you have to cut from the block to fit the starter, swap the flywheel to the 4.6 and use the c4 tq converter. I was planning on posting pics and stuff when I got a little further done. I am getting fuel pump and the motor turns, the pcm is hot (as in powered) but I'm not getting spark. We were thinking it was park neutral that might be hanging it up. I'm in the process now of pulling the entire harness out of the mk-viii.
 

·
Registered
Joined
·
29 Posts
Discussion Starter #15
Yeah, I'm paying for the price of this swap... I got the whole mark for 200$ and it ran. Lol the 3.8 had overheated 4 times and I was fed up with it. So I decided to do this swap. And as for the hood I don't know yet. I don't even have a hood peroid... lol I was thinking of some sort of small cowl hood.
 

·
Premium Member
Joined
·
5,862 Posts
Pics Please

Please post some pics, dude. Tranny and wiring pics would be great!
 

·
Registered
Joined
·
29 Posts
Discussion Starter #18
Ok, so the injectors are fireing, I'm getting fuel to the cylinders, but no spark. The module that's plugs into the 3rd plug on the engine side is pluged in and is bolted down. I pulled the trans harness out of the mkviii and pluged it in with the tranny harness so it gets the park/neutral position. I grounded the brake sence switch off the pcm so it thinks the brake is on... I can't think of anything else asids pulling the ENTIRE harness from the mkviii and plugging it all in and going from there. Which to me sounds like a mess... lol any input??
 

·
Registered
Joined
·
29 Posts
Discussion Starter #20
I thought these dohc engines only had a cam position, and edis is the module I mentioned in my previous post correct.
 
1 - 20 of 42 Posts
Top