Distributor Wire Harness from Coil/Igniter - Question on Lengthening (1 Viewer)

[4Cruisers]

Quick question on my '76 FJ40 ignition upgrade - I installed the FJ60 coil and igniter in the same location as the FJ40 parts and figured out/reconnected all of the wiring except for the two wires to the distributor. The wires are about 6 inches too short. Is there anything special about these wires, or can I simply splice in more wire of the same gauge using crimped connections covered with heat shrink tubing?

 

[lcwizard]

If they're the ones I'm thinking of, one of them is shielded wire for noise suppression. I've shortened one that was broken.
I'm not sure what noise Toyota was trying to suppress. Radios, computers and other circuitry can be affected by EMI.
Maybe a more educated electronics wizard here can elaborate

 

[lcwizard]

MSD 8862 Shielded Magnetic Pickup Cable, 6' - MSD Performance Products

apparently most electronic ignitions prefer them

 

[4Cruisers]

I think I came up with an easy solution by harvesting some connectors from my stash of parts and harnesses:

Last Minute Check Before Removing Distributor

 

[OSS]

Ignition coils produce around 30,000 volts of zapping power going to the distributor. That 'lightening-in-a-can" travels down the coil wire & is distributed to all the spark plug wires accordingly. That whole side of the engine is an EMI hell hole.

One of the the two wires connected to the distributor carries the exceedingly faint signal (generated from the magnetic pickup inside the distributor) to the igniter.
Since that magnetic trigger signal is so faint and the spark plug/coil wires nearby carry such high voltage, a shielded cable is used to help block out any interference.

 

[4Cruisers]

Ignition coils produce around 30,000 volts of zapping power going to the distributor. That 'lightening-in-a-can" travels down the coil wire & is distributed to all the spark plug wires accordingly. That whole side of the engine is an EMI hell hole.

One of the the two wires connected to the distributor carries the exceedingly faint signal (generated from the magnetic pickup inside the distributor) to the igniter.
Since that magnetic trigger signal is so faint and the spark plug/coil wires nearby carry such high voltage, a shielded cable is used to help block out any interference.

View attachment 1506411

Thanks, looks like I have some more reading to do. For now, it's idling fine, but haven't taken it out for a drive yet. I did separate the distributor wires and the coil wire as much as possible, with the OEM section nearest the coil wire at the coil/igniter.

 

[Godwin]

When I installed FJ60 ignition into my 40 I simply patched in an appropriate length of wire without issue.

 

[4Cruisers]

When I installed FJ60 ignition into my 40 I simply patched in an appropriate length of wire without issue.

Thanks, Jim. Good to know. After I wrap up this set of upgrades to the FJ40 I'm back to my '86 FJ60 project vehicle. I'm almost ready to install the 3FE, a project inspired by your article in Four Wheel Drive magazine many years ago. After that, the same upgrades to my '71 FJ40 as on my '76 FJ40.

 

[lcwizard]

that's kind of the thing about theory and practice. In theory the magnetic interference could cause buzzing in the radio or interfere
with high frequency signals or damage circuits but in practice it's a crapshoot. Many electrics are shielded from interference nowadays.
If it's available and easy to use shielded cable go ahead but if I was stranded on a trail I'd have no issues replacing the wire with whatever I had. I have had issues with EMI in shop equipment. When they first released portable plasma cutters you had to run them on separate isolated grounds in your shop. The EMI produced would knock out circuit boards on welders and other equipment that wasn't shielded. I had an ESAB welder for a couple years before ESAB released a plasma. I unknowingly plugged the cutter into shop electrics. It knocked two boards in the MIG welder. ESAB knew this was an issue and fixed it free with upgraded shielded boards. A friend in Colorado with a powder oven had the boards go out in the electrostat gun when he used a plasma in his shop. This is where the stories of people knocking out there PCMs and ECMs while welding or plasma cutting on their truck without disconnecting the battery come from. That's never happened to me and I've welded a lot on my trucks but I hedge my bet by putting the ground clamp as close to the weld as possible

 

[NeverGiveUpYota]

So I’m trying to wrap my head around this tach/noise suppression/coil/igniter connection.
I recently disconnected my tach to see how it would affect an off idle stumble. It ‘seems’ to have worked. Possibly slight hiccup still at high RPMs (w/o tach) I’ll guess it’s still in the 2700/2800 range.
I was lucky enough to be offered inexpensively a working rebuilt carb (has not arrived yet) to see if my hiccup is my carb or not.

My gauge was highly wonky and would be slightly affected by a couple taps on the window but would soon hear back up to 3k tho the RPMs weren’t truly there.
As for the noise suppression, I used to have a buzz w/ the radio on... it would seem it’s gone now.
A coil is relately easy and painless to replace but the igniter assy appears to be $$$$ which I don’t have right now.

Can I pull it, add heatsink epoxy, clean up the connections (again, I cleaned the wires end to the coil months ago) and reuse it or am I truly looking at buying a new one?