Quadrajet choke question

[Slooptin]

Hey guys, got a carb issue I'm trying to sort out. my carb (17080512) was set up to have a secondary choke pull off (hot air choke), and currently doesn't have one. I'm rebuilding the carb and I was originally having an issue with the choke not closing on start up. could this be the culprit/is the secondary pull off necessary? Also if i buy the pull off/linkage, where does the vacuum line need to be routed to?

 

[Bextreme04]

Hey guys, got a carb issue I'm trying to sort out. my carb (17080512) was set up to have a secondary choke pull off (hot air choke), and currently doesn't have one. I'm rebuilding the carb and I was originally having an issue with the choke not closing on start up. could this be the culprit/is the secondary pull off necessary? Also if i buy the pull off/linkage, where does the vacuum line need to be routed to?

No, its my understanding that the secondary pull off actually acts as an additional restriction to keep the secondary's from opening too fast and has nothing to do with the choke closing. The choke closing when cold is purely mechanical and should happen with none of the other choke stuff working at all. It is mechanically closed by a spring inside the round choke housing. It is not uncommon for the spring to break when it gets old. I would take the three screws off of the housing and take a look at the spring. If the linkage is all present and functional, you should be able to hook the spring onto the lever inside the choke housing and then rotate it until it tensions up and closes the choke plate. I have a 17080213 and it is also a hot air system with the secondary pulloff. I converted mine to electric choke and blocked off the hot air lines, but I can maybe provide pics of everything all connected right when it was fully functional in the hot air configuration if I took any. Maybe post pics of your current setup and I can point out anything that is missing or wrongly connected?

 

[AuroraGirl]

may not be a qjet but its half of one. this by chance representative of a truck unit on a sbc manifold in anyway?

 

[Slooptin]

No, its my understanding that the secondary pull off actually acts as an additional restriction to keep the secondary's from opening too fast and has nothing to do with the choke closing. The choke closing when cold is purely mechanical and should happen with none of the other choke stuff working at all. It is mechanically closed by a spring inside the round choke housing. It is not uncommon for the spring to break when it gets old. I would take the three screws off of the housing and take a look at the spring. If the linkage is all present and functional, you should be able to hook the spring onto the lever inside the choke housing and then rotate it until it tensions up and closes the choke plate. I have a 17080213 and it is also a hot air system with the secondary pulloff. I converted mine to electric choke and blocked off the hot air lines, but I can maybe provide pics of everything all connected right when it was fully functional in the hot air configuration if I took any. Maybe post pics of your current setup and I can point out anything that is missing or wrongly connected?

Gotcha. I think mine may have just been out of adjustment + hot air tube was rusted apart + primary pulloff was shot. so those may have been contributing to the choke not working originally. Just trying to figure out what the PO messed with.

I'll post some pics when its all back together. I'd like to keep the hot air choke for the time being since that's what it came with and I'm anal about returning stuff to original functioning condition before i modify it.

Btw, where did you hook your electric choke to

 

[bullcube]

I had to convert one once, I think the electric choke fit on with no issues. Used the accessory wire, but you will want a resistor inline or it will come off too quickly unless it's summertime in Phoenix (don't recall the ohms needed...)

 

[Dave M]

Wire it from the ignition source, via a two prong oil pressure switch so it is only powered when the engine is running.

 

[Bextreme04]

NAPA PN#ECH OP6616 is the choke heater switch. It's $14 and my local napa has it in stock. It can be screwed into the location where there is a 1/4" pipe plug above the oil filter housing in the side of the block.

 

[Slooptin]

Thanks guys, appreciate the help/knowledge

 

[Slooptin]

NAPA PN#ECH OP6616 is the choke heater switch. It's $14 and my local napa has it in stock. It can be screwed into the location where there is a 1/4" pipe plug above the oil filter housing in the side of the block.

Sorry to dig this up one last time, but if I switch to an electric choke, am i running one wire from a power source to the switch and then another wire from the switch to the choke?

 

[75gmck25]

I assume an '85 would have a choke power source, so you will have to check the wiring diagram. My '75 did not originally have an electric choke, so I had to find an ignition-on power source to use.

You need ignition-on power to one terminal on the choke heater switch, and the other terminal has the wire running to the electric choke. The switch is turned on by oil pressure, so you only get power to the choke when the engine is actually running.

 

[Dave M]

Sorry to dig this up one last time, but if I switch to an electric choke, am i running one wire from a power source to the switch and then another wire from the switch to the choke?

Correct, as 75gmck25 has advised.

​

​

​

 

[85 Squarebody76]

I just ran a +12 volt wire from the positive side of ignition coil to the choke wire .. The +12 volt wire is only hot when the ignition is on and truck is running.. no other wires needed... works well for me..

 

[AuroraGirl]

I just ran a +12 volt wire from the positive side of ignition coil to the choke wire .. The +12 volt wire is only hot when the ignition is on and truck is running.. no other wires needed... works well for me..

Key on will drain battery, almost did it once(i have it same way)
But it is a simple route. I wired mine with a fuse tap as to not disturb wiring.

You must be registered for see images attach

I forgot which one its under, probably Wiper(off road use)

Anyway, OP has a 78, if OP wants to go this route I have like 100 brass fuse taps for a glass fuse box

You must be registered for see images attach

(78 k10, they slip under one side of the fuse but in the snap cavity too, then a spade can go on it)

 

[85 Squarebody76]

The wire is only hot when the motor is running which means the alt is charging the batt... no other time so it don't drain the battery...

 

[AuroraGirl]

The wire is only hot when the motor is running which means the alt is charging the batt... no other time so it don't drain the battery...

well i hope your electric choke never wears or experiences failure or starts to fail, that would be an annoying stall-condition but with no rhyme or reason and maybe just stranded somewhere. id at least be concious of it