How do you guys set up your harness when you go from fuel injection to carb? I need help in this. In my harness I'm wanting to keep my torque converter lock up, ac, in tank fuel pump, oil pressure wiring, coolent temp sensor wiring, electric fan, Heater, headlights ect. Can anyone post info and pictures up on how they set up their harness, did you make a new one? Re use your old one? I'm running an hei distributer and a carter 600 carb.

 

The torque converter lockup is about the only thing you will need to buy something additional (an aftermarket lockup kit) if you want to make it functional again. Everything else you hook up like normal. If something doesn't exist any more to plug into, you leave it unplugged. All the gagues will work as normal as will the HVAC, A/C, etc.

The vacuum line that goes to your HVAC system (which isn't a wiring issue, but I thought I'd mention it anyway) will need to find a new home. A fitting that will provide full manifold vacuum. It needs that vacuum to move the vacuum servos under the dash to direct the air to the proper vents (if you don't supply a vacuum source it defaults to the DEFROST vents out the top of the dash).

I leave the ECM in place, personally, because it does various little helpful things still like priming the fuel pump for 2 seconds at key-on.

 

I'm wanting to rip the old harness and computer out though.

 

You can do that, too. The ECM harness is different from the wires that run the gagues and HVAC stuff.

I always leave my ECM wiring in place so I'm sure there's something that the ECM does that will need extra attention. I just can't think what it would be right now.

For sure it won't prime the fuel system for 2 seconds at key-on. That's definitely an ECM function. So power to the fuel pump will only be provided through the oil pressure sender when it gets above ~5PSI of oil pressure. That's why I like the 2 second prime function. It fills the carb up if it's been sitting unused for a while allowing for a quick startup. If you rely only on the OPSU to power the fuel pump it will take some cranking before the fuel pump will start and push fuel up to the carb. Not a big deal if it only sits for a few days. But if it's sitting for weeks everything is going to be dry and in need of that fuel before it will fire.

 

Well this is my daily driver so it won't be sitting except while I'm previewing the swap. So all the sensor wires and the power wires will all be there, along with the accessories If I remove the main wiring and the ECM? If so then all I should need to worry about would be the fuel pump which I'd wire to the ignition switch

 

does anyone have a picture of their harness after this?

 

Bump

 

I've yet to pull my harness apart. Plenty of posts. Most say leave the driver side intact as that's to the relays and things. The passenger side you will need a few wires but you can weed those out. I was far too lazy to do anything with mine yet as my new motor still is not working properly. I zip tied it and stuck it in the fender opening for now.

I don't know about your '86 but my ECM in my '90 needs to be in place as far as I can tell. My gauges didn't want to work without it. In fact I forgot one ground on the back of the head and that prevented my speedo from working. The motor ran and everything else fine. That was a fun 2 weeks tracking down wires.

As for lockup it depends on your circuits. It will be different if you have a Normally Open or a Normally Closed Solenoid in the transmission. I built my own lockup cheap. Works great!

 

'90+ the speedo signal comes from the ECM
On earlier cars VSS signal goes to speedo first,then the ECM

 

iv decided to just leave the wiring and computer in place so i can get the motor done, i got into a car wreck thursday so i decided that since my car was down anyways to get repaired i was going to swap the motor.

 

What does the coolent temp sensor on the intake next to the fuel rail do? Is it for the fan or is that the one in the head?

 

The one in the intake is the coolant temperature sensor for the ECM. The one in the driver side head is the temp gauge sending unit. The one in the passenger side head is the coolant temp switch for the radiator fan.

 

i only had 2 sensors for the coolent temp? the one on the intake and the one for the gauge, would the one on the intake tell the ecu to turn the fans on at a certain temp? im only running the stock single fan.

 

bump, also i got my intake yesterday for my new motor and need to know what goes in the holes on the intake, what controls the fan and what sensor i need to get, and i think i found my power wire for the distributer, its a pink wire, but i cant find the white wire for the tach, closest iv come is a wire that was with my power wire that is black with a white tracer