converting from carb to EFI

[fordfreak300]

Yeah I know I'm a die hard carb fan, but here in the land of the smognazi we like to call California, I can not do what i want to do and keep my car street legal. I would like to know everything I will need to obtain to do this swap. Any details such as what to hook up where would be nice. FYI I cut any extra connectors out of my wiring harness that I didn't need. This is the sad part, I didn't save the connectors and it is an 86 harness. I am now kicking my butt up and down over that one. Anyway can ya guys start throwing to some advice on everything I will need to start collecting to do the swap?


Before those that ask for more details on why I am swapping, it is because I want to run a super charger and be smog legal. Here in California they actually set up smog stops to check out your cars. i will not currently pass that visual when thy pull me over. My intake manifold and carb are not carb e.o. for the state of California.

Thanx for your help.

[Rbuckley]

There are a couple of threads that I and many of us had started in response to that exact question. Its not a trivial swap and it would actually be alot easier if you obtained a donor car for you engine parts, sensors, computer, fuel lines, and wiring harnesses.

Here is a short list of what I obtained to do the swap...

-engine wiring harness and computer from 1986 mustang GT 5 speed car
-MAP sensor
-Wiring for the fuel pump relay, Wiring for the inertia switch, and wiring for the fuel pump, as well as the described pumps and switches (inertia, fuel pump, and pump relay)
-fuel filter
-'86 sending unit and fuel pump into a newer replacement fuel tank
-Upper and lower intake manifolds and throttle body
-Gaskets and whatnot
-02 harness and sensors
-fuel rails and injectors
-efi specific distributor, TFI module, and coil

You would also need various air sensors and the fuel lines from an EFI specific car. Im sure I left out much of the sensors and whatnot that you would NEED considering you are trying to pass emissions and smog standards in Cali

Here are some links to some helpful forum posts as well as some good sites to visit...

http://vb.foureyedpride.com/showthre...ght=Conversion
http://vb.foureyedpride.com/showthre...ght=Conversion
http://vb.foureyedpride.com/showthre...ght=Conversion

http://fordfuelinjection.com/
http://www.veryuseful.com/mustang/tech/engine/

Hope that helps a little

Many people have done it with other harnesses but this was the easiest route for me to go. I have since changed my mind and am sticking with the carb setup though so now I have all this EFI stuff to get rid of.

[fordfreak300]

Ok here is a it of good news. I found the connectors I cut off. I am such a good pack rat I kept them all these years. I can put them back on. I will be doing that while I am gathering parts. SO I am working off of an 86 harness. I guess that means get all the right parts and do a mass air conversion. No need for a new main harness I am assuming and hoping.

I have an MSD 6A box with MSD distributor. Will that still be ok with the EFI swap or will I need to change out the MSD distributor?
RBuckley thankyou for the links I will be reading them over very closely.

Also if anyone can post any pics of the connectors for the EFI conversion so I know what I am looking at before i get started it would be very helpful. That way I know what plugs into what.

[v8only]

NICE, you'll love efi!

Don't get too attached to that 86 harness, it's just speed density,.......


you can do this two ways as far as the wiring goes:

1. rewire the ENTIRE car from tail panel to under the hood. that 86 harness you have is a NO GO for your wiring harness on your 84. the connectors are NOT the same, so you're going to have to splice it in. however, if you rewire the entire car front to rear with an 86 ONLY harness, everything will be plug and play.

2. get a mass air harness from an 88+ and just splice it in. See, even if you do the entire wiring swap, you're STILL going to be left with speed density, which is a no go with your cam, and you're still going to have to splice in that 4 wire harness to convert to mass air.


Although thomas (slick 5.0) should have an entire front to back 86 harness (pm me if you're interested) I really suggest snagging an 88+ mass air harness and splicing that in. I believe stangboy from this site has done it several times, and I've seen him walk people here step by step and wire by wire on the efi conversions.


the actual efi lines are the easy part. nab them from a junkyard car, but do NOT bend or cut them especially up front where the hard lines meet the soft lines. On the donor car it will require unbolting the lines from the body, and drilling out a few rivets. On your car, simply drill and screw it in.

no doubt you want a better than stock intake, but I May have a stocker lying around.

I'd suggest going to ebay and spending $150 on an explorer intake. If you look around, you can get the explorer intake with the explorer injectors too, those are 19# injectors, but with an improved spray pattern. Use them with the mustang fuel rail.


EDIT: worth mentioning, Tony runs an explorer intake that he ported himself with his afr heads. he took off the rpm 2 intake that was on there, and said for his combo it seems to flow every bit as good, and possibly gained more torque back.

if you do go with the explorer intake, make sure it's got the egr port in the middle (only 96/early 97 intakes had them) or you won't be smog legal.

[fordfreak300]

I think I have the 86 harness already in the car. This is why I am needing pics so I can really determine what I have. I don't care about splicing anything I need in. I can solder and heat shrink with the best of em. I first need to determine what I really do and do not have. I just got off the phone with my uncle whom originally had the car and he can't remember now. If I do not have the 86 harness I have no problem splicing in to my existing harness. If that is possible to do that way. If it as an 86 harness I will convert it over to mass air while I am swaping in the fuel injection.

If anyone can take any pics of their EFI connections and post them for me I would greatly appreciate it. Figuring out my wiring harness is a huge imapct on what i will start getting first as far as collecting parts and installing on the car.

Luckily I had only cut off connectors on one side of the car the rest are still all in place on the passanger side.

[v8only]

no problem, let me know exactly which pictures you want and i'll take them for you.......shooting pics under the dash at the pass side kick will be difficult, but I can try.

[fordfreak300]

I really would like to see some under the hood pics. Such as the Connectrs for the fuel injection harnes so I can see what they look like. Really just any connectors in the engine compartment that I can use to determine my Wiring harness in my engine bay. No need for in the kick panel under the dash, that is asking way too much. I am only looking for easy to take pics. This is for identification purposes only.

[v8only]

no problem.

[Rbuckley]

I know you are looking for pictures of the harness in the engine bay but I will still offer pictures of the harness out of the car.

Here is the engine bay harness...
http://www.buckster.rageear.com/imag...ne_harness.jpg

and pictures of the harness that leads to the tail lights and inertia switch...
http://www.buckster.rageear.com/imag...ht_harness.jpg

The pictures are big and you can zoom in pretty close to check the harness out.

Like i said, it may not be exactly what you are looking for but maybe it could help. Good luck.

[fordfreak300]

what year is that harness out of?

[fordfreak300]

If anything I would like to just put in the engine harness. If my car does not have an 86 harness in it already. I am still trying to determine that.

[fordfreak300]

Ok here's the thing. i was looking at the pics of the engine harness that Rbuckley posted. I was looking at the connector to the computer. Now if I had an 86 harness then I would have to have that connector some where in my car. Or atleast the wires and they would have ha to have been spliced onto other connectors as I do not have a computer in my car. I can not find evidence of either. This has to be an 84 wiring harness.

This is now where I am at. Can I take an 86 harness and splice everything else into my 84 harness that is already in my car? Has anyone done this before that can offer up some help with this?

[Rbuckley]

what year is that harness out of?

Whoops sorry that is an 86 5.0 liter harness...

[fordfreak300]

Rbuckley I see on your thread the 86 engine harness plugs in the old harness? Is this true? have you finished your conversion yet? If it really does plug into the old engine harness then that is the route I will take then convert it to mass air at the same time.

[v8only]

man, I swear that 86 harness will only plug into an 86 harness, i've heard this time and time and time again.

mark, if you do wind up splicing a harness in, save yourself the time, splice in an 88+ one, it already has mass air on it, and you won't have to convert and splice the 86 harness that you JUST spliced into.

[Rbuckley]

Rbuckley I see on your thread the 86 engine harness plugs in the old harness? Is this true? have you finished your conversion yet? If it really does plug into the old engine harness then that is the route I will take then convert it to mass air at the same time.

What is being called into question, I am assuming, is whether it will plug into th dash harness, correct? Supposedly it does plug into the existing harness...well my harness...which is harness on a 1985 mustang GT 5 speed. I am not positive that it will work with an existing 1984 harness which, I am assuming, is what you have. It may work but I dont want to be quoted on that.

I have not done anything with my parts past collecting them. And unfortunately I am not going to be using any of them. I am sticking with my carburetor setup. So no I have not completed, nor attempted this swap

[Rbuckley]

man, I swear that 86 harness will only plug into an 86 harness, i've heard this time and time and time again.

mark, if you do wind up splicing a harness in, save yourself the time, splice in an 88+ one, it already has mass air on it, and you won't have to convert and splice the 86 harness that you JUST spliced into.

You may be right and if that is the case I totally aggree with the choice of using an 88+ harness. I have heard that it does work with the '85 dash harness only, but I have also heard that the whole car harness for 86 is specific only of that year. Who knows.

v8only knows alot more about this stuff than I do so I would take his word over mine.

[fordfreak300]

hmm I guess I will try to swap an 89+ engine harness in. Were is stangboy when you need him?

[v8only]

now i'm not sure if it was stangboy or someone else....he's the one that had that white notch that was wrecked and rebuilt....that dude.

http://vb.foureyedpride.com/showthre...ght=conversion

there is a decent thread. seems the only guy who had a plug and play scenario was the guy who had a CFI powered 85, then he said everything was plug and play with the efi harness.....however everyone else in that thread stated that they had to do (minor) splicing.

they also said the 92/93 harness is the best one to grab, as it has the fuel relay built into it, and requires less work to splice in....(although that harness certainly isn't as easy to find as the earlier ones.

mark, do you still want the pics? I'll be home in an hour or two and can take them then of the underhood connections.

[fordfreak300]

no I won't be needing the pics, Rbuckely's pics helped me out. It was actually easier seeing it all laied out and able to determine what the connectors look like and all. This is looking like it is going to be a project and a half.

[Rbuckley]

no I won't be needing the pics, Rbuckely's pics helped me out. It was actually easier seeing it all laied out and able to determine what the connectors look like and all. This is looking like it is going to be a project and a half.

Glad I could help

[fordfreak300]

This is going to get intertesting.

[fordfreak300]

Since I am using my full MSD system for the ignition will I have to use a TFI distributor or can I reuse my old set up?

[v8only]

that's a damn good question...I'm near certain that the tfi setup isn't bypassed even if you're using the msd setup. besides, the stock distributor has that timing spout coming off of it that needs to be pulled to time the car. I think that that's part of the dist and not the main harness...I'll have to look when I get home.

if you find that the msd setup eliminates the tfi, let me know, but I seriously doubt it..

anyone reading this know the answer?

[fordfreak300]

Actually the MSD bypasses th duraspark system all together. So it may be possible to reuse my old distributor? I hope someone can answer this question.