Electric Choke Problem-Q-Jet

[Mr Red]

OK... Thought this was finished. But, have 12V at choke at both cold engine and well after engine warm up. Choke light doesn't come on at start up but bulb is OK cause it'll flash when you try to shut rig down and it wants to diesel. Thing is, if I unplug the choke lead, it still has the fast idle cam stepped up until I push it off w/ my finger--touch the throttle & back to higher idle. Weird thing is, after it runs for about 20-30 minutes, fast idle cam will kick off and stay at normal, warm idle.

I'm stumped. Anyone know if there is a relay somewhere that would control the fast idle cam and/or juice going to the lead that connects to the choke that could be bad and causing the problem? Any ideas appreciated.

<font color=red>David, '86 K5</font color=red>

 

[Rich84]

I had a similar problem with the fast idle cam after I rebuilt my holley. (a carb that will probably be replaced soon, since I still can't get better than about 8.5 mpg with it). I can't tell if the electric choke ever actually works, since it's so hot here I don't need it, but to fix the cam, I just backed the screw off to the point that the idle would'nt be too fast even if it stayed on. Another idea is that the choke linkage is binding. Hope this helps.

 

[Jeff 86K5]

Sounds like maybe your choke is toast or you have a bad connection. They have a PTC (Positive Thermal Coeffeicient) pill inside them that heats up when electricity is applied. Like a resistor. The heat causes a bi-metal disc to snap and open up a set of contacts. This turns off the choke and the light in the dash.

The coil spring that works the butterfly on the carbuerator is also made of bi-metal that expands and contracts as the temperature changes. This opens the choke when the engine warms.

The tang on the coil may be adjusted by loosening the screws that mount the choke to the carb and rotating it. There are marking dots on the choke. Only move it a couple of dots at a time to adjust this.

You might check your electrical connection. You have only one lead that plugs on the choke terminal. The ground is through the strap to the carb. Maybe your ground needs cleaning.

Hope this helps.



Jeff 86K5