Question for those who have done 3.8 cfi swap to 5.0 mass air

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Question for those who have done 3.8 cfi swap to 5.0 mass air

November 14, 2004, 09:04:50 PM

Does anyone know what the round connector near the computer on the 3.8 does? it has 3 wires one red, one yellow, and one brown with a green stripe. This plug differs from the one on the mustang harness which has a square shaped plug with 8 pins, only 5 pins are used and the five wires going to them are one red, one brown with green stripe, one light grey with yellow stripe, one black with white stripe, and one light brown wire. Both connecters share two of the same colored wires, but what are the rest for? Does anyone have experiece doing this or are able to point me in the direction of schematics to solve this problem? (already looked at chiltons, this part of the harness not listed in book)

Thanks,

Tony

Re: Question for those who have done 3.8 cfi swap to 5.0 mass air

Reply #1 – November 17, 2004, 07:41:37 PM

Its going to the fuel pump relay in the trunk. Somewhere there was a write up for the rewiring for the Mustang harness. But:
Yellow=Hot always heading to fule pump relay contact
Red=EEC power relay voltage heading to intertia switch, then fuel pump relay coil
Tan/Green=From ECU to other side of fuel pump relay coil

Some also have the pink/black which you also need to hook up for Mass Air computers

Re: Question for those who have done 3.8 cfi swap to 5.0 mass air

Reply #2 – November 17, 2004, 07:59:36 PM

GrannysBird, I found this at Granny's site

Might help a little with the other wire info...

(http://www.members.tripod.com/~grannys/enginewiring87MustangV8ECAharness.html )

Connector C-135 (black)
(8) terminals.
Located next to the ECA's main connector, in the Mustang's passenger side kick panel area.
Modifications required as noted below...
Ckt97 tan/lt green - connect to "-" side of the fuel pump relay coil.
Ckt359 black/white - connect to neutral safety switch (other side of neutral safety sw connects to connector C-201 Ckt199 ly blue/yellow)
Ckt361 red - connect to inertia switch. connect other side of inertia switch to "+" side of fuel pump relay coil.
Ckt687 grey/yellow - connect to IGN SW. "run".

Re: Question for those who have done 3.8 cfi swap to 5.0 mass air

Reply #3 – November 19, 2004, 01:31:31 AM

Here joefriday has a nice write up. Have fun w/ the pop-ups. :) The mustang doesn't have the yellow wire. Your yellow wire(constant +, to run fuel pump) probably won't be long enough from the cfi, as the one joefriday is talking about I believe is from the 87-88 3.8L, mine wasn't cuz the selinoid is on opposite of the engine bay w/ 3.8L cfi, I used a cougar harness that already had the wire. You may have to run your own wire. It goes from the + on the starter selinoid to the connector by the computer. I know you'll need to have constant power to yellow, just match the tan/lt greens together, and the reds together. I think the post says what to do w/ the rest. I just used the cougar harness, just had to match the 3 colors and go. Good luck.

Re: Question for those who have done 3.8 cfi swap to 5.0 mass air

Reply #4 – November 20, 2004, 10:58:17 AM

Thanks guys, the motor is assembled now and about to go in! so hopefully it will be getting wired up as well! I've got to run to down and start working on it again so wish me luck!

Thanks Tony