Anyway to test an electric choke?

[JPL]

Hi all, anyway to test an electric choke? The 440 was having a harder time starting than normal,   so I took the air cleaner off and left the hood open, this way I can see the Holley 750 vac secondary carb with electric choke from inside the car, and noticed when I turn the key to the "on" postion and pump it once, the choke does not close. It worked in the past, the 12v power is still there, (only when the key is in the on position), good ground, it just doesn't close anymore. Anyone know what gives? Anyway to test it?  

Thanks!

[elacruze]

Check to see your linkages aren't bound, or got a squirrel stick in them. I don't know the Holley system, if you have a counterweight to close the choke plate check to see if it's broken off or something crazy. If it's closed by spring, perhaps that's broken-maybe inside the choke-stat. (electric device).

As far as testing, you should only have power coming into the choke mechanism after the engine starts; typically the choke power will run through an oil pressure switch, so the choke doesn't open while you sit in the car with the key on/engine off. Test the choke mechanism for continuity while cold. After it heats sufficiently, there's a bi-metal contact inside that opens after it gets hot enough and closes only when the underhood/engine temp falls to cold.

[elacruze]

After re-reading I see that you have no oil pressure switch in the choke loop. Be sure you have no power to the choke with the key off. Even a small short to choke can open the spring over time.

[SUPERSTAR14]

Hi all, anyway to test an electric choke? The 440 was having a harder time starting than normal,   so I took the air cleaner off and left the hood open, this way I can see the Holley 750 vac secondary carb with electric choke from inside the car, and noticed when I turn the key to the "on" postion and pump it once, the choke does not close. It worked in the past, the 12v power is still there, (only when the key is in the on position), good ground, it just doesn't close anymore. Anyone know what gives? Anyway to test it?  

Thanks!

The 12v is to heat the choke spring and open the choke butterfly. You'll need to check when key has not been on and choke is cold (ambient temp). Ensure the choke butterfly moves freely with light spring pressure keeping it closed. The choke can be adjusted by loosening the screws that retain it and rotating it until the butterfly closes. Do not turn choke much further than "just closed". Then you'll be able to start the car and watch the choke open as it warms up. If it doesn't open make sure there is still 12v. If it still does not open after confirming the 12v, replace choke thermostat and adjust as previously described.
Good luck
-Pat

[JPL]

Hi all, anyway to test an electric choke? The 440 was having a harder time starting than normal,   so I took the air cleaner off and left the hood open, this way I can see the Holley 750 vac secondary carb with electric choke from inside the car, and noticed when I turn the key to the "on" postion and pump it once, the choke does not close. It worked in the past, the 12v power is still there, (only when the key is in the on position), good ground, it just doesn't close anymore. Anyone know what gives? Anyway to test it?  

Thanks!

  The choke can be adjusted by loosening the screws that retain it and rotating it until the butterfly closes. Do not turn choke much further than "just closed". Then you'll be able to start the car and watch the choke open as it warms up. 

Thanks, but I thought by doing that adjustment, that would control how soon or how late the choke opens (vid below)..............also, to clarify, yes it does have 12v only when the key is in the "on" position, and I canoot close the butterfly manualy at all, hot cold, key on or off, but it is not binding anywhere, it used to work fine......

http://www.youtube.com/watch?v=0H5IBSFgYJE

[SUPERSTAR14]

Try opening the throttle by hand, then see if the choke butterfly will close with your other hand.

[JPL]

I might have it, quick question, when the car is cold & just sitting there, should the choke plate be open or closed?

[SUPERSTAR14]

The choke will not fully close (set) until the throttle is depressed. That is one of the reasons why we "pump" the accelerator when it's cold, the other would be to give it a shot of fuel.

[JPL]

I think I got it, I took the choke off, the arm that connects to the rod that goes to the choke plate had no spring tension at all, so I took the  black thermo cap off, I don't think the arm from inside the thermo housing was sitting in the curled spring end. At least I think it's supposed to sit in there, but now it has tension, and seems to be closing on start up......