ECU Elimination

[follman8r]

Im doing a V8 swap of an Explorer 5.0 into an 87 ranger that had a 2.0. The motor and trans are not in yet while im switching it to carb'd. Ill be running a ready to run dist. and external coil.

Question:
Im pulling apart the wiring harness and trying to chop out as much as I can. Can I just chop out the whole ECU (Idle Speed Control Module or w.e. its called)? Vehicle still needs to have funtional lights and such as Its gonna be my sunday driver.

Sent from my SM-G928V using Tapatalk

 

[adsm08]

What I think I would do is find the wires for your lights, wipers, washers, etc, basically everything you are keeping.

Cut everything else.

 

[follman8r]

What I think I would do is find the wires for your lights, wipers, washers, etc, basically everything you are keeping.

Cut everything else.

Thats what I'm thinking. What I'm not sure of is if the ECU even has a hand in any of that or if it mostly just controlled the engine and diverts power to the switches for the lights, etc.
i.e. am I going to have to trace the wires and bypass power around the ECU? I want ti get rid of that whole box. It doesnt make sense to me to have the ECU if all it does is recieve and disseminate a 12v current.

Sent from my SM-G928V using Tapatalk

 

[adsm08]

I think you are severely overestimating the function of the computer on your 30-year old carb'd truck.

This isn't the freaking Enterprise-D, where you can't flush a toilet without the main computer. All of the functions that you need to keep to be safe and legal, like lights, are powered directly from the battery, and switched directly by the switches you use to control them. No power for lights, wipers, horn, any of that runs anywhere near the computer, even physically speaking.

 

[RonD]

+1 ^^^

1987 ECU calculated air:fuel mix on the fly, and set idle and EGR functions
Suggested spark advance, and monitored EVAP system.

No connection to dash or any body electrics, except..........................

.........Fuel Pump Relay, if you are keeping the electric in tank fuel pump you will need to GROUND this relay, it will then come on when you turn on the key.
I would prefer an Oil Pressure Switch GROUND or eliminating the electric pump altogether.
Electric fuel pumps are great, except in an accident or rollover, then they just keep on happily pumping out gasoline which is very dangerous

When electric fuel pumps were first used on carb engines, no computers, an oil pressure switch was used to GROUND a fuel pump relay.
If oil pressure is below 5psi then No Ground and no pump, above 5psi then fuel pump is on.
Carbs have gasoline in the bowl for starting, so no priming needed.

If a fuel line breaks in an accident(engine runs out of gas) or in a roll over then engine stops running and so does electric fuel pump.
Very easy to wire since you already have the fuel pump relay in place

 

[Angie]

"Electric fuel pumps are great, except in an accident or rollover, then they just keep on happily pumping out gasoline which is very dangerous"


in both my pinto and 83 build I have used an inertia switch from 90's rangers. either wired into ground loop or + wiring. both builds i have them wir3ed in the + wire loop (under rug on pass side).

this will kill all power to the electric pump(s).

cheers

 

[follman8r]

This isn't the freaking Enterprise-D, where you can't flush a toilet without the main computer.

I was 90% sure it didnt really do anything i just didnt want to start hacking and totally screw the wiring. Electrical is not my strongsuit lol

.........Fuel Pump Relay, if you are keeping the electric in tank fuel pump you will need to GROUND this relay, it will then come on when you turn on the key.

The later models had electric pumps? The 2.0 had a mechanical pump so i just assumed the sending unit was basically a straw like my old '84 Ranger.

My V8 doesnt have a mechanical pump so i was going to get an old holley red but if theres a stock pump pushing 5-7psi i might just leave it....


Btw this is super helpful yall I really appreciate it.



Sent from my SM-G928V using Tapatalk