Converting Carb to EFI

84blkstang

Member

Jun 4, 2003

544

1

18

Springfield MO

Jul 8, 2004

#1

• Jul 8, 2004

• #1

I have a carbed 302 with the mods listed below in the sig, anyways as the title says i really want to switch to EFI, I love the simplicity of the carb, the look, and the cheaper peformance. Now the downsides, the carb will run rich in more humid weather, so bad that you smell raw gas at a stoplight. Then some days it runs fine, other days it wont. I have had it professionally tuned and it still runs like ****. I am sick of having to hang my foot on the break and gas and pump the petal so it will start, the bad idle at start up, and the poor mileage. I have found a guy that deals strictly in mustangs, he has two complete wiring harness, 3 complete EFI manifolds w/ injectors along with Mass air meters and cpu's for $200, my question is how hard will this be and what other stuff do i need? I know i need a intank fuel pump, distributor, so if anyone could chime in and tell me what i need to complete this because i am really sick of having that shop retune the carb. thank you and sorry for the long post

 

GREG91GT

Member

Jun 3, 2004

207

0

17

MISSOURI

Jul 8, 2004

#2

• Jul 8, 2004

• #2

FUEI INJECTION

I HAVE FUEL INJECTION AND STILL HAVE ALL THE SAME PROBLEMS YOU DO WITH THE CARB,MY MOTORS NOT PROPERLY TUNED YET BUT DONT EXPECT TO THROW FUEL INJ ON AND ALL OF YOUR TUNING PROBS TO BE GONE, I THOUGHT THE SAME THING

 

84blkstang

Member

Jun 4, 2003

544

1

18

Springfield MO

Jul 9, 2004

#3

• Jul 9, 2004

• #3

i know it wont go away but i hope it will run better then my current setup. Also a good tuned fuel injection will get better then a good tuned carbed.

 

MSM0075

Member

May 13, 2003

741

0

16

Central Jersey

Jul 10, 2004

#4

• Jul 10, 2004

• #4

I'm thinking about eventually doing the same in my '82GT, Carb piss's me off, Somehow it got out of tune and im filling this damn thing like once a day, and I dont drive around like an idiot. Its rediculous amounts of money wasted.

 

J

Js5ohLX

Member

Apr 5, 2004

287

0

16

Ohio

Jul 10, 2004

#5

• Jul 10, 2004

• #5

The swap isn't too bad, but you should really look into what year the harness is, what kind of computer it is, and you really don't want to use a stock maf or intake, your performance will suffer. You'll need to get an efi distributor as well.

 

jrichker

StangNet's favorite TOOL

In Remembrance. Thank you for your contributions

Mar 10, 2000

27,512

2,811

234

Dublin GA

Jul 10, 2004

#6

• Jul 10, 2004

• #6

Your best bet is to find a donor 89-93 5.0 Mustang to rob the fuel tank, lines & pump from. The main computer harness is going to have lots of wires that don't match up with your current car. You may end up splitting the two harnesses open and removing the wires from the EFI harness that don't work the EFI & adding in the ones from the 84 that run the lights, instruments, etc. The simpler way to do it would be to buy the EFI conversion harness from Ford Motor Sports.

It probably obvious that isn't a easy weekend project. If you garage your car during the winter, this would be an excellent winter project. Look carefully at the wiring diagrams of the car that the EFI harness came from and at wiring diagrams for your car. Identify the wires that are needed from both harnesses, their length, colors and routing. Sit down and draw out your wiring plan, and have the new harness and wiring scheme all laid out on paper before you start.

here's some links to help...
89-93 wiring diagrams - http://www.autozone.com/servlet/UiB..._us/0900823d/80/19/59/5a/0900823d8019595a.jsp

79-88 wiring diagrams - http://www.autozone.com/servlet/UiB..._us/0900823d/80/16/71/3c/0900823d8016713c.jsp

Some other links... http://www.veryuseful.com/mustang/tech/engine/ for pictures of what the EFI harness looks like and the plugs tha are on it.

 

84blkstang

Member

Jun 4, 2003

544

1

18

Springfield MO

Jul 10, 2004

#7

• Jul 10, 2004

• #7

is that the ford racing conversion harness i can get from summit for 225 or so? if so i will get it. Does anyone know if this is plug and play or will i have to cut some stuff? i need all the help i can get. Thanks for the links they are now saved on my cpu. I know the stock stuff is restrictive but i dont have the money for aftermarket stuff right now that will come in time. I have to get it running right before i worry about performance.

 

84blkstang

Member

Jun 4, 2003

544

1

18

Springfield MO

Jul 11, 2004

#8

• Jul 11, 2004

• #8

bump

 

old_blue

15 Year Member

Nov 3, 2003

1,783

282

124

Jul 11, 2004

#9

• Jul 11, 2004

• #9

Like everyone said, the biggest thing that you need to worry about is the wiring. I tink everyone will agree, once you get that taken care of you will be good to go. Make sure you get the fuel lines from a v-8 the 4cyl ones wont work. and make sure you tape off the lines before running them so they dont get crud in them. I had to do this on my conversion too, but wiring harness worked for either because it was an 88-89 swap. I wouldnt try wiring it yourself. I would get the conversion wiring kit. It will save you a lot of time and cursing.

 

84blkstang

Member

Jun 4, 2003

544

1

18

Springfield MO

Jul 11, 2004

#10

• Jul 11, 2004

• #10

so does anyone know if the FMS wiring harness is a plug and play for my car it says it is used to retrofit 86-95 fuel injection in older cars. I called summit and he said it would work fine it contains all of the electrical connections that i need. Can i put a inline electrical pump instead of pulling the tank, also if i have to pull the tank will a fuel pump off a 87-93 work are the tanks the same i am new to efi so i need all of the help i can get

 

84blkstang

Member

Jun 4, 2003

544

1

18

Springfield MO

Jul 11, 2004

#11

• Jul 11, 2004

• #11

ttt

 

old_blue

15 Year Member

Nov 3, 2003

1,783

282

124

Jul 11, 2004

#12

• Jul 11, 2004

• #12

the one from a 87-92 should work (in tank). When I did my conversion I left the 4 cyl pump in and it was fine. I am told they are the same.

 

IndyBlk5.0

New Member

Nov 24, 2003

1,122

1

0

New Whiteland, IN

Jul 11, 2004

#13

• Jul 11, 2004

• #13

Go to a different shop to get the carb tuned, they dont know what they are doing.

 

84blkstang

Member

Jun 4, 2003

544

1

18

Springfield MO

Jul 12, 2004

#14

• Jul 12, 2004

• #14

i would like to stay carbed but the missouri winters are not really good for an older car. They are hard to start and take forever to warm up. Back to the FMS wiring harness does anyone know if anything else is required to use this?

 

84blkstang

Member

Jun 4, 2003

544

1

18

Springfield MO

Jul 14, 2004

#15

• Jul 14, 2004

• #15

bump

 

old_blue

15 Year Member

Nov 3, 2003

1,783

282

124

Jul 15, 2004

#16

• Jul 15, 2004

• #16

Have you tried calling ford or summits tech department? I dont know if it is plug n play.

 

mob

the guy who hits on his mom

20+ Year Stangneter

Oct 3, 2003

2,566

136

104

Dallas, TX

Jul 15, 2004

#17

• Jul 15, 2004

• #17

sry cant help you, just wanted to say i dont know how u guys do it with carbs everyday, there so much work, efi's are so easy

 

84blkstang

Member

Jun 4, 2003

544

1

18

Springfield MO

Jul 15, 2004

#18

• Jul 15, 2004

• #18

well it has to be re-tuned about once a week, I think I can predict the weather with it because it will run awsome right before it rains. Then after it rains it runs like ass, then the wonderful gas mileage... well i wont get into that. I just want to go to efi because it is more practical, even though parts are more expensive i will deal with that.