1986 305 k10 sensor question

[v8jeeptj]

I am working on changing the intake and carb on my K10. I have a couple of questions;

1. My thermostat housing has a sensor which I assume is the temp switch and another nipple with all kind of smog vaccume lines. The temp switch has a wire that runs from it to some sensor in the carb and then back into the harness. What is this wire that runs to the carb and is it needed?

2. On the drivers side block next to the exhaust port there is a sensor with one wire. Is this the knock sensor and can I leave it dissconected since I am getting rid of all smog stuff?

 

[livid4dirt]

That should be the temp sender (drivers side by exhaust port). Knock sensor on my old 305 was passenger side of bock towards the tranny.

 

[v8jeeptj]

That should be the temp sender (drivers side by exhaust port). Knock sensor on my old 305 was passenger side of bock towards the tranny.

If that is the temp sensor then what is the sensor in the thermostat housing with one wire coming out then going to a sensor on the carb then the main harness

 

[livid4dirt]

Is that a Computor Controlled Carb?

 

[livid4dirt]

If so CCC, then the one at the thermo housing is a temp sensor for carb. The one on the drivers side by exhaust is a temp sender for your temp gauge.

 

[v8jeeptj]

If so CCC, then the one at the thermo housing is a temp sensor for carb. The one on the drivers side by exhaust is a temp sender for your temp gauge.

I dont think it it computer controlled, the only wires I see running to it are the electric choke and the wire that runs from the thermostat to the carb

 

[livid4dirt]

I'am no Q-Jet genius, so maybe someone else can chime in and point ya in the right direction. Can you set it up the same way without all the smog? On mine i de-smogged when i dropped the new crate engine in and just have the temp sender for gauge hooked up. Did not re-call mine having the same set-up as yours.
It had a total cluster of temp related vaccum type fittings coming out of thermo housing going to charcoal cannister and other places, but that was about it.

 

[v8jeeptj]

Could this have something to do with ECS? I found this older post.

67 older temp sender iis in intake up front, 68 up is in cyl head between the cylinders yep

80-up in intake is for carb, some have it and some dont,
depend son EST or ESC and the year and make and model too, i know 86 305 trucks have it in intake and is one black wire from it to carb, it is an extra control in the carb that others dont have

there are several minor variations of the EST and ESC systems 80-86(passenger cars and 1/2 tons/carb systems)

 

[paratrooper307]

I have the same setup (It was originally an 85 305 that I replaced with a crate 350) and I disconnected all of the smog stuff. That sensor with the vacuum ports is a temperature sensor and has to do with the EFE, EGR and other smog equipment. I run full length headers so I pulled out all those vacuum lines, and blocked off the EGR. I also switched to a standard distributor over the computer controlled one.

It runs great. The true CCC's which you mostly see on cars of that era, have a blue plug on the mixture control solenoid (which hooks into that sensor on the thermostat housing) and a TPS sensor near the throttle linkage, they also come with a computer-controlled distributor. Trucks have an electronicly controlled mixture solenoid with a grey plug (one wire is for 12V power, the other is for the sensor), no TPS sensor and a computer controlled distributer (this is the additional harness that comes off the distributor and electronically controls timing, assuming you have a stock distributor)

The sensor by the exhaust is for the coolant gauge, as others have said. You can just leave the sensor with the 4 vacuum ports, or remove it and plug the hole. If you choose to retain the quadrajet with the electronic mixture solenoid, you will have to leave it hooked up to the thermostat housing sensor, or the engine will run pig rich (black smoke out the exhaust rich, as I discovered when I knocked the plug off).

I guess the long and short of it is that the carb and truck will work fine without all the vacuum and emissions hardware, just make sure you plug up unused ports on the carb and get your timing and carb set properly. For me, the biggest benefit was cleaning up the engine compartment, and the peace of mind of not having to worry about all those brittle, 27+ year old vacuum lines breaking or leaking and being a pain everytime I worked under the hood.

 

[v8jeeptj]

Thanks for the help