Stock EFI System

[Mhstiles]

Asking forgiveness in advance because there's so much I don't know, but I'm in the planning stages of a build and am planning on using a 94-95 5.0 donor engine. Will the kit come with the wiring needed to use the stock EFI system? Won't I need to use the ECU, wiring, and sensors from the donor? Thanks for any feedback, the knowledge here is incredible!

[JimLev]

You'll need all the wiring, sensors, and ECU from the donor.
A Ron Francis fuse box and associated wiring will come with the kit. That's mostly for the exterior lights, horns, interior electric items, etc.

[Mhstiles]

Thank you!

[Big Blocker]

X2 on what has been mentioned above . . . you will need all wiring that is related to the EFI system(s), all sensors, actuators, relays and the EEC. Unless you intend to delete some of the "smog related" devices (EGR, TAB, TAD and the carbon canister), you'll need those devices also.

All of the EFI wiring is somewhat "stand-alone" from the the rest of the cars systems (the Ron Francis harness) but there are a few interconnects for ignition power and fuel pump operation.
The Ron Francis harness controls all your lighting, horns, cooling fans, brake lights and turn signals and gauges. It will also control (if you option to add them) A/C, heat, seat heaters, wipers . . . just about anything you choose to add.

HTH

Doc

[Mhstiles]

X2 on what has been mentioned above . . . you will need all wiring that is related to the EFI system(s), all sensors, actuators, relays and the EEC. Unless you intend to delete some of the "smog related" devices (EGR, TAB, TAD and the carbon canister), you'll need those devices also.

All of the EFI wiring is somewhat "stand-alone" from the the rest of the cars systems (the Ron Francis harness) but there are a few interconnects for ignition power and fuel pump operation.
The Ron Francis harness controls all your lighting, horns, cooling fans, brake lights and turn signals and gauges. It will also control (if you option to add them) A/C, heat, seat heaters, wipers . . . just about anything you choose to add.

HTH

Doc

So if i don't use those smog devices i can simply not connect the wiring to them? Thank you, did you do a similar build?

[Just puttering]

You will want to "tune" the eec. You can delete the smog inputs from the tune. Otherwise the eec will constanty be looking for those inputs, which could cause head aches! What eec do you have? If you want to have some fun wiring.... You could use the whole harness from the donor! To reiterate Docs post, any harness could run the efi! Find a wiring diagram for your year car, you will notice from the computer to the engine all the items you need to address, also you will find how few wires go to the cars main harness, the rest as they say is simple simple!!!
Edit: yes you need the efi harness from the doner (eec out to engine, pull and keep everything that goes to the eec plug) for any main harness that you use!

[Big Blocker]

To answer your question, yes, mine is a stock EFI system with all the smog related devices deleted. To the best of my recollection about early EEC's, you can't just "de-program" the EEC to ignore the errors that will develop with these devices deleted, some things need to have "resistors" placed in line so the EEC still thinks the devices are still there. The solenoids that operate the TAB/TAD, carbon canister are easily "by-passed with a resistor - the EGR needs a little more then that, but still easy.
I run an A9L EEC out of an '89 Mustang and it's been in the car for 18 years - with no issues.

You will want to make sure you have the harness that came out of the car you are using as a donor, as well as the EEC - color codes change from the earlier '88-'93 to the '94 and later for small blocks, The harness, EEC and the harness for the O2 sensors change from year to year.

Doc

[i.e.427]

Asking forgiveness in advance because there's so much I don't know, but I'm in the planning stages of a build and am planning on using a 94-95 5.0 donor engine. Will the kit come with the wiring needed to use the stock EFI system? Won't I need to use the ECU, wiring, and sensors from the donor? Thanks for any feedback, the knowledge here is incredible!

The thing that none of the above posts reference is that the 94/95 Mustang engine harness is much more integrated into the chassis harness of the donor vehicle than the earlier 87-93 Mustangs. IMHO you have two options. 1. Send the entire harness chassis/engine to Art Cuesta at Wire Diet or 2. Purchase the Ron Francis Cobra-75 engine harness https://www.ronfrancis.com/prodinfo....ber=COBRA%2D75 and integrate it with the Ron Francis chassis harness https://www.ronfrancis.com/prodinfo.asp?number=FFR%2D06. You will also need to change out the upper intake manifold and throttle body to match up with the harness along with an ECU from a 87-93 Mustang.

[Mhstiles]

That just got a lot more complicated. Carburetion is beginning to sound more appealing.

[Joel Hauser]

Big Blocker mentioned that "To the best of my recollection about early EEC's, you can't just "de-program" the EEC to ignore the errors that will develop with these devices deleted, some things need to have "resistors" placed in line so the EEC still thinks the devices are still there. The solenoids that operate the TAB/TAD, carbon canister are easily "by-passed with a resistor - the EGR needs a little more then that, but still easy."
I'm using a 1996 mustang GT engine with the stock EFI. I deleted the EGR, carbon canister, downstream O2 sensors and cats. I'm using BAMA SCT tuners. They won't won't delete these functions from the EEC program, for legal reasons. Does anyone know where I can find instructions on how to make and install the resistors or other devices that will bypass these devices.
Thanks
Joel

[HVACMAN]

Also, if I understand correctly, depending on what state you register the car in, you may be required to keep all of the emissions devices on the car. In Texas we don't have to keep any of it.

[Big Blocker]

Joel,

The TAB/TAD and carbon canister solenoid coils can be replaced with 75 ohm 2 watt resistors - this will effectively "fool" the EEC into thinking that the activation coils are still in play and operating.

The EGR needs a "bridge" installed between power, signal and signal return. Here's the bridge schematic:



This arrangement will fool the EEC into thinking the variable valve in the EGR housing is still regulating exhaust gases.

This resistor bridge can be purchased from several vendors, packaged in a nice single device . . . search for EGR delete plug

Doc

[Joel Hauser]

thanks Doc; I'm going to give it try.
Joel