Why two vacuum lines from distributor?

[FuzzFace2]

It’s definitely not a California truck and I don’t believe it has feedback. It does have AC and it was factory installed. The wire originally came up and over the engine.

In some pics before I removed the carb, I’m pretty sure it was attached here:

http://forum.garysgaragemahal.com/file/n97014/99CF1968-609C-42E1-A2CA-FE7CE40EA7F5.jpeg

If the wires from the plug on the fender go inside the cab then it would not be easy to just unplug and remove the harness.

That also looks like it goes to the choke, it is a little different than my 81 that has 1 wire from ALT to choke with hot air asst.

As for using it for keyed power you could turn the key on and see if hot then but dose it also need power when cranking also? If so you would need to check for that at the ssame time.

The other question is what will it power and how much power (amps & volts) dose that part take to make it work and will that wire in the plug be able to handle it?

Dave ----

ps them pictures you post really mess up trying to quote a post

Had to remove the pictures.

[FrazerJames]

Yep, you got that set up right. From that plug all the wires feed into the firewall. I’ll see if I can spot where they go to from there inside the cab.

Really, what I was hoping for us that red/yellow wire might be live for the key switch.

Yeah, just checked and this plug leads to a mess of wrapped wires heading into the firewall and who knows from there unless I start unwrapping the factory set up. Either way, I do need to figure out a place to tap into keyswitch that also has constant 12 volts while running.

[FrazerJames]

It’s definitely not a California truck and I don’t believe it has feedback. It does have AC and it was factory installed. The wire originally came up and over the engine.

In some pics before I removed the carb, I’m pretty sure it was attached here:

http://forum.garysgaragemahal.com/file/n97014/99CF1968-609C-42E1-A2CA-FE7CE40EA7F5.jpeg

If the wires from the plug on the fender go inside the cab then it would not be easy to just unplug and remove the harness.

That also looks like it goes to the choke, it is a little different than my 81 that has 1 wire from ALT to choke with hot air asst.

As for using it for keyed power you could turn the key on and see if hot then but dose it also need power when cranking also? If so you would need to check for that at the ssame time.

The other question is what will it power and how much power (amps & volts) dose that part take to make it work and will that wire in the plug be able to handle it?

Dave ----

ps them pictures you post really mess up trying to quote a post

Had to remove the pictures.

Yeah, I think the image issue has something to do with the float - it’s driving me a bit nuts too.

It’s going to the Sniper EFI system - It definitely needs 12 volts at key ON, but needs power when starting as well. It sounds like it’s ok if it only gets 10 volts for starting though. They don’t give any amperage requirements, and from the research I’ve done no one seems to have a problem with the stock wiring.

[FuzzFace2]

Yeah, just checked and this plug leads to a mess of wrapped wires heading into the firewall and who knows from there unless I start unwrapping the factory set up. Either way, I do need to figure out a place to tap into keyswitch that also has constant 12 volts while running.

So I get this right the plug has 2 wires a yellow and a red one.

They go down to the plug in the other picture that has 2 other wires on the same side of the plug the 2 wires are on.

The other 2 wires on the same side go back into the harness and into the cab.

The other side of the plug has 4 wires coming from the harness that is also from the cab.

If so I dont know why they would send wires out and then back in only to have 2 go to the choke?

I would post up all the wire colors on each side of the plug so someone can look them up for you.

Dave ----

hate this quote

[FrazerJames]

Yeah, just checked and this plug leads to a mess of wrapped wires heading into the firewall and who knows from there unless I start unwrapping the factory set up. Either way, I do need to figure out a place to tap into keyswitch that also has constant 12 volts while running.

So I get this right the plug has 2 wires a yellow and a red one.

They go down to the plug in the other picture that has 2 other wires on the same side of the plug the 2 wires are on.

The other 2 wires on the same side go back into the harness and into the cab.

The other side of the plug has 4 wires coming from the harness that is also from the cab.

If so I dont know why they would send wires out and then back in only to have 2 go to the choke?

I would post up all the wire colors on each side of the plug so someone can look them up for you.

Dave ----

hate this quote

Here’s the thing Dave - If I’m reading this correctly (found in another thread looking for the same thing but they didn’t say where they tapped into), that Red/Yellow wire going to the choke may actually be hot for both. There’s an excellent chance I’m very wrong...

[FrazerJames]

Yeah, just checked and this plug leads to a mess of wrapped wires heading into the firewall and who knows from there unless I start unwrapping the factory set up. Either way, I do need to figure out a place to tap into keyswitch that also has constant 12 volts while running.

So I get this right the plug has 2 wires a yellow and a red one.

They go down to the plug in the other picture that has 2 other wires on the same side of the plug the 2 wires are on.

The other 2 wires on the same side go back into the harness and into the cab.

The other side of the plug has 4 wires coming from the harness that is also from the cab.

If so I dont know why they would send wires out and then back in only to have 2 go to the choke?

I would post up all the wire colors on each side of the plug so someone can look them up for you.

Dave ----

hate this quote

Sorry for the confusion. No, it’s one red wire with yellow hashes. At the plug it just goes into another red with yellow hashes and into the cab. No weirdness that I can tell.

[FuzzFace2]

Here’s the thing Dave - If I’m reading this correctly (found in another thread looking for the same thing but they didn’t say where they tapped into), that Red/Yellow wire going to the choke may actually be hot for both. There’s an excellent chance I’m very wrong...

http://forum.garysgaragemahal.com/file/n97022/BEED2A2E-8C28-45CE-9D32-772CB5E7ACAD.jpeg

So it is EEC and has a computer in the cab?

I hear the EEC systems can be a tuff cookie to work on or with.

I dont see the choke set up in there or my eyes are that bad?

Is the wire you are looking at on the right upper side of that?

It looks to be 1 wire R/Y and not 2 wires a R & Y.

Or I have the wrong colors and still thinking of the vacuum lines LOL

Dave ----

[Rusty_S85]

The vacuum lines probably were for advance on the backside of the distributor and retard on the front side. Under some conditions they used one vs the other, usually decided by the ECU.

Not sure what the wires to the carb are, but if you gave me the wire colors I could figure it out. I'd need both the primary as well as the secondary color.

Some are for the stepper motor for leaning the air/fuel ratio. Some are for throttle solenoids. There were several combinations and the wire colors are the key.

I've always been curious about the non computer setups myself. My original distributor I pulled from my '82 to replace with a new one actually has the dual advance can with the inner line plugged and using just the outside terminal for advance. I think the inner was for retard and the outter was your typical advance. Sort of like on my dual advance can on my '56 292 Y8, the outter is to venturi vacuum for advance and the inner is to manifold vacuum to pull advance out. When you go full throttle manifold vacuum drops but venturi vacuum stays so you lose this retard feature of the advance and you get more advance under load. This was done as there was no mechanical advance on this distributor. On my '82 I question how it would work cause you couldnt do the same thing as ford did on my '56 as the '82 has a mechanical advance to take over when vacuum is lost.

Mine was not hooked up and my original emission decal is so faded I dont know if it even shows how it hooked up in the first place.

[FuzzFace2]

The vacuum lines probably were for advance on the backside of the distributor and retard on the front side. Under some conditions they used one vs the other, usually decided by the ECU.

Not sure what the wires to the carb are, but if you gave me the wire colors I could figure it out. I'd need both the primary as well as the secondary color.

Some are for the stepper motor for leaning the air/fuel ratio. Some are for throttle solenoids. There were several combinations and the wire colors are the key.

I've always been curious about the non computer setups myself. My original distributor I pulled from my '82 to replace with a new one actually has the dual advance can with the inner line plugged and using just the outside terminal for advance. I think the inner was for retard and the outter was your typical advance. Sort of like on my dual advance can on my '56 292 Y8, the outter is to venturi vacuum for advance and the inner is to manifold vacuum to pull advance out. When you go full throttle manifold vacuum drops but venturi vacuum stays so you lose this retard feature of the advance and you get more advance under load. This was done as there was no mechanical advance on this distributor. On my '82 I question how it would work cause you couldnt do the same thing as ford did on my '56 as the '82 has a mechanical advance to take over when vacuum is lost.

Mine was not hooked up and my original emission decal is so faded I dont know if it even shows how it hooked up in the first place.

Rusty,

Looking over his pictures I found he did not have a 2 port vacuum can on the dist. but 2 different vacuum lines going down to a single port can.

The lines Tee'd in close to the can and 1 line looked to have a check valve in it.

I have no clue where the 2 lines got hooked up to but a guess with the check valve they wanted 1 side not to pull vacuum from the other and only on the dist. can?

Crazy set up for sure

Dave ----

[Rusty_S85]

Yeah, I think the image issue has something to do with the float - it’s driving me a bit nuts too.

It’s going to the Sniper EFI system - It definitely needs 12 volts at key ON, but needs power when starting as well. It sounds like it’s ok if it only gets 10 volts for starting though. They don’t give any amperage requirements, and from the research I’ve done no one seems to have a problem with the stock wiring.

If you are doing sniper I havent confirmed it but lots of people swear holley recommends using the key hot in run and crank as a trigger for a relay then provide straight battery voltage to the sniper through the relay.

Im tempted to do this myself as I could in theory splice into the key hot wire for the ignition system as it has to be hot in the run and crank position. In theory it shouldnt harm the ignition system using it as a trigger and should take nothing away from the voltage to the ignition system. But I think I will try to drop my column and find a wire from the ignition switch itself that is hot in key on as well as crank and splice a jumper wire into it to run as a trigger for the sniper. Think it would be easier as I can run this wire along the dash and out through the firewall with the wiring for the passengerside lighting harness to my auxiliary fuse/relay box that will be mounted by the battery.

For the sniper itself there is no amperage rating but they do want more than 11 volts though otherwise the sniper cant fully function properly. The FiTech goes a bit further to 10.5 volts as a min.